10. How to Guides¶

10.4.1. How to take the C66x DSP out of reset with Linux running on A15¶

This document describes the procedure to bring the C66x core out of reset after booting Linux, or at the u-boot prompt.These steps are necessary in to order to load an application on the C66x core, without interfering with the operation of Linux running on the A15.

1. Once Linux has booted, launch the target configuration.

2. With the target configuration launched, right click on K2x.ccxml and select “Show all cores”

3. This will bring up the Non-Debuggable Devices section. Right click and connect the CS_DAP_Debug_SS core.

4. Go to Tools>GEL files and load the evmk2x.gel file by right clicking on the GEL file window. The Gel file would typically be located in the CCS installation under \ccsv6\ccs_base\emulation\boards\evmk2x\gel\

5. Once the GEL has been successfully loaded, go to Scripts>default and select K2x_TakeDSPOutofReset.

6. At this point the console would indicate that the DSP is out of reset.

7. Now the DSP cores can be right-clicked and connected successfully.

10.4.2. Target Configuration¶

10.5.1. Setup CCS for EVM and Processor-SDK RTOS¶

This page provides information on configuring CCS to work with both the EVM and the Processor-SDK for RTOS.

After installing the Processor-SDK RTOS, start CCS and it will automatically detect the newly installed components (products):

If you chose to install the SDK package in a different folder from where CCS is installed (e.g. C:\TEMP\RTOS-SDK\am57x), then you will need to add the path to the search path for CCS to locate the new packages. The screenshots below demonstrate the process to setup the CCS environment; the sequence for a Linux host is the same.

From CCS, select “Window -> Preferences”:

In the Preferences window, select “Code Composer Studio -> RTSC -> Products” in the panel on the left. Then, press the “Add” button on the panel on the right:

Next, verify the newly discovered products. If everything is correct, press the “Finish” button on the bottom:

When prompted, restart CCS for changes to take effect. You will see newly discovered products from the custom path.

1. In CCS, navigate to Help -> Check for Updates and select “Sitara device support” and “TI Emulators” and click Next.

2. Click “Next” again, select “I accept the terms of the license agreements” and click Finish to begin the installation.

3. You may be prompted to restart CCS for the updates to take effect. Click “Restart Now” when prompted to complete the installation.

In CCS, you need to create a Target Configuration for your EVM to be able to connect to the target. This configuration defines your:

• Connection to the target (XDS, FET, etc.)
• Target device (AM437x GP EVM, AM57x GP EVM, etc.)
• GEL file for hardware initialization. A GEL file is basically a “batch file” that sets up the CCS debug environment including memory map, PLL, clock, etc.

CCS comes with basic configuration that can be used to configure your particular setup. In the example below, we provide details for a GP AM437x EVM; configuration information for other supported EVMs are also provided as needed.

For EVM specific instructions, refer to the Hardware User’s Guide for your EVM

C:\ti\ccsv6\ccs_base\common\targetdb\devices\66AK2G02.xml

Line #1

<?xml version="1.1" encoding="UTF-8" standalone="no"?>
to
<?xml version="1.0" encoding="UTF-8" standalone="no"?>

From CCS, select “File -> New -> Target Configuration File”:

The AM437x GP EVM supports embedded XDS100V2 USB Emulation through the MicroUSB AB connector. Select

• Connection: Texas Instruments XDS100v2 USB Debug Probe
• Board or Device: EVMAM437X

Useful Tip

If you enter the starting numbers of your device in the Board or Device field, the list will show the relevant subset.

Here is a table showing configuration information for all supported EVMs in the Processor-SDK RTOS:

Next, save the target configuration by pressing the Save button:

Next, test the target configuration by pressing the Test Connection button. This will confirm that you have successfully created an emulator connection with your board.

From CCS, select “View -> Target Configurations”:

Open “User Defined” list and right click on the target configuration file that was just saved and select “Launch Selected Configuration”:

After launch, you can connect to a core. For GP AM437x EVM, select Cortex A9 and select “Connect Target”:

After connecting to target, check the console for status. Typically, the end of the configuration will indicate success or failure. For GP AM437x EVM, you will see the message “AM437x GP EVM Initialization is Done”:

After connecting to the boot master core – typically the ARM core – you may need to connect to a slave core in order to run code. Depending on your SOC, the slave core can be

• DSP C66x
• ARM M4
• PRUSS
• IVAHD

Typically the slave cores will wait in reset state until the master core wakes up the slave core to run code. To connect to the slave core on AM57x, go to Scripts menu in CCS Debug View and under AM572x MULTICORE Initialization enable the corresponding sub system clock. For example, enable DSP11SSClkEnable_API for the first DSP core. After running the clock enable option, you can connect to the core.

On AM57xx devices, all the timers on the chip have their suspend control signal routed to the A15 core. Which means that if any of the slave cores are using these timers, the timers will continue to run even when the slave core has been paused. The timer will only pause when the A15 core is halted.

This is confusing while debugging code on slave cores if you are relying on timer for logging, inserting delays or if the timer keeps firing interrupts even when the core is halted. One such scenario occurs with GPtimer5 when DSP developers are using SYS/BIOS. The OS uses GPtimer5 on the DSP and forces a frequency check to confirm the timer configuration, however the OS can’t gain access to the timer due to the hook up of the suspend control signals.

Due to this issue the SYS/BIOS developers will need to configure an additional CCS configuration check to connect the GPTimer suspend control signal to the DSP as shown in the image below:

If you face any problems, first check these basic items:

• Power cycle your target.
• Check the USB cable. One simple way to do this is to connect another device to the USB and ensure the cable works.
• Check host driver. Even with CCS turned off, your host should list the TI XDS as a USB device. If this does not work, try a different USB port.
• Latest emulation package. Ensure that you have the latest emulation files as specified in the Getting Started Guide.

If this does not resolve your problem, see these additional resources:

• Troubleshoot CCS
• Troubleshoot XDS100
• Troubleshoot XDS200
• Troubleshoot XDS560

10.5.2. Update environment when installing to a custom path¶

This page will provide configuration information if the SDK is installed in a custom path.

Useful Tip

To avoid changing environment variable for each new shell, modify environment variable file directly. This file is the setupenv file located in the SDK root directory.

Installing the SDK in a folder other than where CCS is installed will require modifications to CCS to be able to discover the SDK. See the Setup CCS How To page explaining how to update CCS configuration.

Installing the SDK in a folder other than the default (C:\TI for Windows, /home/[user]/ti for Linux) requires modifications to SDK RTOS scripts in order for recompilation and example/test creation to work properly.

In all the commands below, replace [version] with the appropriate version of the software/tool.

CCS installation and toolchain paths can be customized by setting the TOOLS_INSTALL_PATH environment variable prior to running the SDK level setupenv script. This feature is used if CCS and the toolchains are installed somewhere other than the default C:\ti location.

For example, environment configuration assuming CCS is installed to [os_base]\ti_temp and SDK RTOS has been installed to default path, [os_base]\ti :

• Windows

C:\> set TOOLS_INSTALL_PATH=C:\ti_temp

C:\> cd C:\ti\processor_sdk_rtos_[soc]_[version]

C:\ti\processor_sdk_rtos_[soc]_[version]> setupenv.bat

Gives the output:

Optional parameter not configured : CG_XML_BIN_INSTALL_PATH
REQUIRED for xdc release build
Example: set CG_XML_BIN_INSTALL_PATH=C:/ti/cg_xml/bin
Optional parameter not configured : DOXYGEN_INSTALL_PATH
REQUIRED for xdc release build
Example: set DOXYGEN_INSTALL_PATH=C:/ti/Doxygen/doxygen/1.5.1-p1/bin
**************************************************************************
Environment Configuration:
    PDK Directory             : /ti/PDK_AM~3/packages/
    CGTOOL INSTALL Directory  : C:/ti_temp/ccsv6/tools/compiler/ti-cgt-c6000_[version]
    TOOLCHAIN A15 Directory   : C:/ti_temp/ccsv6/tools/compiler/gcc-arm-none-eabi-[version]
    TOOLCHAIN A8 Directory    : C:/ti_temp/ccsv6/tools/compiler/gcc-arm-none-eabi-[version]
    TOOLCHAIN A9 Directory    : C:/ti_temp/ccsv6/tools/compiler/gcc-arm-none-eabi-[version]
    TOOLCHAIN M4 Directory    : C:/ti_temp/ccsv6/tools/compiler/ti-cgt-arm_[version]
    FPULIB_PATH               : C:/ti_temp/ccsv6/tools/compiler/gcc-arm-none-eabi-[version]/lib/gcc/arm-none-eabi/[version]/fpu
    CROSS_TOOL_PRFX           : arm-none-eabi-
    XDC_INSTALL_PATH          : C:/ti/xdctools_[version]_core
    BIOS_INSTALL_PATH         : C:/ti/bios_[version]
    IPC_INSTALL_PATH          : C:/ti/ipc_[version]
    EDMA3LLD_BIOS6_INSTALLDIR : C:/ti/edma3_lld_[version]
    NDK_INSTALL_PATH          : C:/ti/ndk_[version]
    IMGLIB_INSTALL_PATH       : C:/ti/imglib_c66x_[version]
    UIA_INSTALL_PATH          : C:/ti/uia_[version]
    PROC_SDK_INSTALL_PATH     : C:/ti/processor_sdk_rtos_[soc]_[version]
**************************************************************************
Changing to short name to support directory names containing spaces
current directory: C:/ti/processor_sdk_rtos_[soc]_[version]
PROCESSOR SDK BUILD ENVIRONMENT CONFIGURED
**************************************************************************

• Linux

$ export TOOLS_INSTALL_PATH=~/ti_temp

$ cd ~/ti/processor_sdk_rtos_[soc]_[version]/

~/ti/processor_sdk_rtos_[soc]_[version]$ source setupenv.sh

Gives the output:

Optional parameter not configured : CG_XML_BIN_INSTALL_PATH
REQUIRED for xdc release build
Example: export CG_XML_BIN_INSTALL_PATH="~/ti/cg_xml/bin"
Optional parameter not configured : DOXYGEN_INSTALL_PATH
REQUIRED for xdc release build
Example: export DOXYGEN_INSTALL_PATH="~/ti/Doxygen/doxygen/1.5.1-p1/bin"
**************************************************************************
Environment Configuration:
    PDK Directory             : /home/[user]/ti/pdk_[soc]_[version]/packages
    CGTOOL INSTALL Directory  : /home/[user]/ti_temp/ccsv6/tools/compiler/ti-cgt-c6000_[version]
    TOOLCHAIN A15 Directory   : /home/[user]/ti_temp/ccsv6/tools/compiler/gcc-arm-none-eabi-[version]
    TOOLCHAIN A8 Directory    : /home/[user]/ti_temp/ccsv6/tools/compiler/gcc-arm-none-eabi-[version]
    TOOLCHAIN A9 Directory    : /home/[user]/ti_temp/ccsv6/tools/compiler/gcc-arm-none-eabi-[version]
    TOOLCHAIN M4 Directory    : /home/[user]/ti_temp/ccsv6/tools/compiler/ti-cgt-arm_[version]
    FPULIB_PATH               : /home/[user]/ti_temp/ccsv6/tools/compiler/gcc-arm-none-eabi-[version]/lib/gcc/arm-none-eabi/[version]/fpu
    CROSS_TOOL_PRFX           : arm-none-eabi-
    XDC_INSTALL_PATH          : /home/[user]/ti/xdctools_[version]_core
    BIOS_INSTALL_PATH         : /home/[user]/ti/bios_[version]
    IPC_INSTALL_PATH          : /home/[user]/ti/ipc_[version]
    EDMA3LLD_BIOS6_INSTALLDIR : /home/[user]/ti/edma3_lld_[version]
    NDK_INSTALL_PATH          : /home/[user]/ti/ndk_[version]
    IMGLIB_INSTALL_PATH       : /home/[user]/ti/imglib_c66x_[version]
    UIA_INSTALL_PATH          : /home/[user]/ti/uia_[version]
    PROC_SDK_INSTALL_PATH     : /home/[user]/ti/processor_sdk_rtos_[soc]_[version]

PROCESSOR SDK BUILD ENVIRONMENT CONFIGURED
*******************************************************************************

The RTOS SDK top level Makefile can now be used to rebuild SDK RTOS components with CCS and toolchains installed in a custom installation path.

SDK RTOS component installation paths can be customized by setting the SDK_INSTALL_PATH variable prior to running the SDK level setupenv script. This feature is used if the SDK is installed somewhere other than the default C:\ti location.

For example, environment configuration assuming CCS is installed to the default path, [os_base]\ti and SDK RTOS has been installed to [os_base]\ti_temp:

• Windows

C:\> set SDK_INSTALL_PATH=C:/ti_temp

C:\> cd C:\ti_temp\processor_sdk_rtos_[soc]_[version]

C:\ti_temp\processor_sdk_rtos_[soc]_[version]> setupenv.bat

Gives the output:

Optional parameter not configured : CG_XML_BIN_INSTALL_PATH
REQUIRED for xdc release build
Example: set CG_XML_BIN_INSTALL_PATH=C:/ti/cg_xml/bin
Optional parameter not configured : DOXYGEN_INSTALL_PATH
REQUIRED for xdc release build
Example: set DOXYGEN_INSTALL_PATH=C:/ti/Doxygen/doxygen/1.5.1-p1/bin
**************************************************************************
Environment Configuration:
    PDK Directory             : /ti_temp/PDK_AM~3/packages/
    CGTOOL INSTALL Directory  : C:/ti/ccsv6/tools/compiler/ti-cgt-c6000_[version]
    TOOLCHAIN A15 Directory   : C:/ti/ccsv6/tools/compiler/gcc-arm-none-eabi-[version]
    TOOLCHAIN A8 Directory    : C:/ti/ccsv6/tools/compiler/gcc-arm-none-eabi-[version]
    TOOLCHAIN A9 Directory    : C:/ti/ccsv6/tools/compiler/gcc-arm-none-eabi-[version]
    TOOLCHAIN M4 Directory    : C:/ti/ccsv6/tools/compiler/ti-cgt-arm_[version]
    FPULIB_PATH               : C:/ti/ccsv6/tools/compiler/gcc-arm-none-eabi-[version]/lib/gcc/arm-none-eabi/[version]/fpu
    CROSS_TOOL_PRFX           : arm-none-eabi-
    XDC_INSTALL_PATH          : C:/ti_temp/xdctools_[version]_core
    BIOS_INSTALL_PATH         : C:/ti_temp/bios_[version]
    IPC_INSTALL_PATH          : C:/ti_temp/ipc_[version]
    EDMA3LLD_BIOS6_INSTALLDIR : C:/ti_temp/edma3_lld_[version]
    NDK_INSTALL_PATH          : C:/ti_temp/ndk_[version]
    IMGLIB_INSTALL_PATH       : C:/ti_temp/imglib_c66x_[version]
    UIA_INSTALL_PATH          : C:/ti_temp/uia_[version]
    PROC_SDK_INSTALL_PATH     : C:/ti_temp/processor_sdk_rtos_[soc]_[version]
**************************************************************************
Changing to short name to support directory names containing spaces
current directory: C:/ti_temp/processor_sdk_rtos_[soc]_[version]
PROCESSOR SDK BUILD ENVIRONMENT CONFIGURED
**************************************************************************

• Linux

$ export SDK_INSTALL_PATH=~/ti_temp

$ cd ~/ti_temp/processor_sdk_rtos_[soc]_[version]/

~/ti_temp/processor_sdk_rtos_[soc]_[version]$ source setupenv.sh

Gives the output:

Optional parameter not configured : CG_XML_BIN_INSTALL_PATH
REQUIRED for xdc release build
Example: export CG_XML_BIN_INSTALL_PATH="~/ti/cg_xml/bin"
Optional parameter not configured : DOXYGEN_INSTALL_PATH
REQUIRED for xdc release build
Example: export DOXYGEN_INSTALL_PATH="~/ti/Doxygen/doxygen/1.5.1-p1/bin"
**************************************************************************
Environment Configuration:
    PDK Directory             : /home/[user]/ti_temp/pdk_[soc]_[version]/packages
    CGTOOL INSTALL Directory  : /home/[user]/ti/ccsv6/tools/compiler/ti-cgt-c6000_[version]
    TOOLCHAIN A15 Directory   : /home/[user]/ti/ccsv6/tools/compiler/gcc-arm-none-eabi-[version]
    TOOLCHAIN A8 Directory    : /home/[user]/ti/ccsv6/tools/compiler/gcc-arm-none-eabi-[version]
    TOOLCHAIN A9 Directory    : /home/[user]/ti/ccsv6/tools/compiler/gcc-arm-none-eabi-[version]
    TOOLCHAIN M4 Directory    : /home/[user]/ti/ccsv6/tools/compiler/ti-cgt-arm_[version]
    FPULIB_PATH               : /home/[user]/ti/ccsv6/tools/compiler/gcc-arm-none-eabi-[version]/lib/gcc/arm-none-eabi/[version]/fpu
    CROSS_TOOL_PRFX           : arm-none-eabi-
    XDC_INSTALL_PATH          : /home/[user]/ti_temp/xdctools_[version]_core
    BIOS_INSTALL_PATH         : /home/[user]/ti_temp/bios_[version]
    IPC_INSTALL_PATH          : /home/[user]/ti_temp/ipc_[version]
    EDMA3LLD_BIOS6_INSTALLDIR : /home/[user]/ti_temp/edma3_lld_[version]
    NDK_INSTALL_PATH          : /home/[user]/ti_temp/ndk_[version]
    IMGLIB_INSTALL_PATH       : /home/[user]/ti_temp/imglib_c66x_[version]
    UIA_INSTALL_PATH          : /home/[user]/ti_temp/uia_[version]
    PROC_SDK_INSTALL_PATH     : /home/[user]/ti_temp/processor_sdk_rtos_[soc]_[version]

PROCESSOR SDK BUILD ENVIRONMENT CONFIGURED
*******************************************************************************

The RTOS SDK top level Makefile can now be used to rebuild SDK RTOS components installed in the custom installation path.

When CCS and the SDK RTOS are both installed to custom paths the SDK can be rebuilt by setting the SDK_INSTALL_PATH and TOOLS_INSTALL_PATH variables prior to running the SDK RTOS top level environment setup script. The Windows and Linux environment setup scripts can be found in the following locations, respectively:

• Windows - C:\custom\install\path\processor_sdk_rtos_[soc]_[version]\setupenv.bat
• Linux - /home/[user]/custom/install/path/processor_sdk_rtos_[soc]_[version]/setupenv.sh

The SDK_INSTALL_PATH and TOOLS_INSTALL_PATH environment variables must be set to the custom install path prior to running the environment setup script.

For example, environment configuration assuming CCS and the SDK have been installed to [os_base]\new_sdk_release\ :

• Windows

C:\> set SDK_INSTALL_PATH=C:\new_sdk_release
C:\> set TOOLS_INSTALL_PATH=C:\new_sdk_release

C:\> cd C:\new_sdk_release\processor_sdk_rtos_[soc]_[version]

C:\new_sdk_release\processor_sdk_rtos_[soc]_[version]> setupenv.bat

Gives the output:

Optional parameter not configured : CG_XML_BIN_INSTALL_PATH
REQUIRED for xdc release build
Example: set CG_XML_BIN_INSTALL_PATH=C:/ti/cg_xml/bin
Optional parameter not configured : DOXYGEN_INSTALL_PATH
REQUIRED for xdc release build
Example: set DOXYGEN_INSTALL_PATH=C:/ti/Doxygen/doxygen/1.5.1-p1/bin
**************************************************************************
Environment Configuration:
    PDK Directory             : /NEW_SD~1/PDK_AM~1/packages/
    CGTOOL INSTALL Directory  : C:/new_sdk_release/ccsv6/tools/compiler/ti-cgt-c6000_[version]
    TOOLCHAIN A15 Directory   : C:/new_sdk_release/ccsv6/tools/compiler/gcc-arm-none-eabi-[version]
    TOOLCHAIN A8 Directory    : C:/new_sdk_release/ccsv6/tools/compiler/gcc-arm-none-eabi-[version]
    TOOLCHAIN A9 Directory    : C:/new_sdk_release/ccsv6/tools/compiler/gcc-arm-none-eabi-[version]
    TOOLCHAIN M4 Directory    : C:/new_sdk_release/ccsv6/tools/compiler/ti-cgt-arm_[version]
    FPULIB_PATH               : C:/new_sdk_release/ccsv6/tools/compiler/gcc-arm-none-eabi-[version]/lib/gcc/arm-none-eabi/[version]/fpu
    CROSS_TOOL_PRFX           : arm-none-eabi-
    XDC_INSTALL_PATH          : C:/new_sdk_release/xdctools_[version]_core
    BIOS_INSTALL_PATH         : C:/new_sdk_release/bios_[version]
    IPC_INSTALL_PATH          : C:/new_sdk_release/ipc_[version]
    EDMA3LLD_BIOS6_INSTALLDIR : C:/new_sdk_release/edma3_lld_[version]
    NDK_INSTALL_PATH          : C:/new_sdk_release/ndk_[version]
    IMGLIB_INSTALL_PATH       : C:/new_sdk_release/imglib_c66x_[version]
    UIA_INSTALL_PATH          : C:/new_sdk_release/uia_[version]
    PROC_SDK_INSTALL_PATH     : C:/new_sdk_release/processor_sdk_rtos_[soc]_[version]
**************************************************************************
Changing to short name to support directory names containing spaces
current directory: C:/new_sdk_release/processor_sdk_rtos_[soc]_[version]
PROCESSOR SDK BUILD ENVIRONMENT CONFIGURED
**************************************************************************

• Linux

$ export SDK_INSTALL_PATH=~/new_sdk_release
$ export TOOLS_INSTALL_PATH=~/new_sdk_release

$ cd ~/new_sdk_release/processor_sdk_rtos_[soc]_[version]/

~/new_sdk_release/processor_sdk_rtos_[soc]_[version]$ source setupenv.sh

Gives the output:

Optional parameter not configured : CG_XML_BIN_INSTALL_PATH
REQUIRED for xdc release build
Example: export CG_XML_BIN_INSTALL_PATH="~/ti/cg_xml/bin"
Optional parameter not configured : DOXYGEN_INSTALL_PATH
REQUIRED for xdc release build
Example: export DOXYGEN_INSTALL_PATH="~/ti/Doxygen/doxygen/1.5.1-p1/bin"
**************************************************************************
Environment Configuration:
    PDK Directory             : /home/[user]/new_sdk_release/pdk_[soc]_[version]/packages
    CGTOOL INSTALL Directory  : /home/[user]/new_sdk_release/ccsv6/tools/compiler/ti-cgt-c6000_[version]
    TOOLCHAIN A15 Directory   : /home/[user]/new_sdk_release/ccsv6/tools/compiler/gcc-arm-none-eabi-[version]
    TOOLCHAIN A8 Directory    : /home/[user]/new_sdk_release/ccsv6/tools/compiler/gcc-arm-none-eabi-[version]
    TOOLCHAIN A9 Directory    : /home/[user]/new_sdk_release/ccsv6/tools/compiler/gcc-arm-none-eabi-[version]
    TOOLCHAIN M4 Directory    : /home/[user]/new_sdk_release/ccsv6/tools/compiler/ti-cgt-arm_[version]
    FPULIB_PATH               : /home/[user]/new_sdk_release/ccsv6/tools/compiler/gcc-arm-none-eabi-[version]/lib/gcc/arm-none-eabi/[version]/fpu
    CROSS_TOOL_PRFX           : arm-none-eabi-
    XDC_INSTALL_PATH          : /home/[user]/new_sdk_release/xdctools_[version]_core
    BIOS_INSTALL_PATH         : /home/[user]/new_sdk_release/bios_[version]
    IPC_INSTALL_PATH          : /home/[user]/new_sdk_release/ipc_[version]
    EDMA3LLD_BIOS6_INSTALLDIR : /home/[user]/new_sdk_release/edma3_lld_[version]
    NDK_INSTALL_PATH          : /home/[user]/new_sdk_release/ndk_[version]
    IMGLIB_INSTALL_PATH       : /home/[user]/new_sdk_release/imglib_c66x_[version]
    UIA_INSTALL_PATH          : /home/[user]/new_sdk_release/uia_[version]
    PROC_SDK_INSTALL_PATH     : /home/[user]/new_sdk_release/processor_sdk_rtos_[soc]_[version]

PROCESSOR SDK BUILD ENVIRONMENT CONFIGURED
*******************************************************************************

The RTOS SDK top level Makefile can now be used to rebuild SDK RTOS components installed in the custom installation path using CCS and toolchains installed in a custom path as well.

Installing the PDK in a folder other than the default (C:TI for Windows, /home/[user]/ti for Linux) requires modifications to PDK scripts in order for recompilation and example/test creation to work properly.

The instructions provided in the CCS in Custom Path and SDK RTOS in Default Path section can be used to rebuild components at the PDK level. The only difference is the PDK level setup script should be used instead of the SDK RTOS level setup script. The PDK level setup scripts are found in the following locations on Windows and Linux, respectively:

• Windows - C:\custom\install\path\pdk_[soc]_[version]\packages\pdksetupenv.bat
• Linux - /home/[user]/custom/install/path/pdk_[soc]_[version]/packages/pdksetupenv.sh

The instructions provided in the CCS in Default Path and SDK RTOS in Custom Path section can be used to rebuild components at the PDK level. The only difference is the PDK level setup script should be used instead of the SDK RTOS level setup script. The PDK level setup scripts are found in the following locations on Windows and Linux, respectively:

• Windows - C:\custom\install\path\pdk_[soc]_[version]\packages\pdksetupenv.bat
• Linux - /home/[user]/custom/install/path/pdk_[soc]_[version]/packages/pdksetupenv.sh

The instructions provided in the CCS and SDK RTOS in Custom Path section can be used to rebuild components at the PDK level. The only difference is the PDK level setup script should be used instead of the SDK RTOS level setup script. The PDK level setup scripts are found in the following locations on Windows and Linux, respectively:

• Windows - C:\custom\install\path\pdk_[soc]_[version]\packages\pdksetupenv.bat
• Linux - /home/[user]/custom/install/path/pdk_[soc]_[version]/packages/pdksetupenv.sh

The pdkProjectCreate scripts must be modified in order to build PDK example and test projects only if CCS has been installed to a custom path. The modification is the same for both Windows and Linux. Inside the pdkProjectCreate scripts is a CCS_INSTALL_PATH variable which points to the Code Composer Studio root directory. This variable must be redefined to the new location of the CCS root directory if CCS is installed to a custom path.

• Windows

REM Install Location for CCS
set CCS_INSTALL_PATH="C:\ti\ccsv6"

• Linux

# Install Location for CCS
export CCS_INSTALL_PATH=~/ti/ccsv6

10.5.3. Prevent BeagleBone board reset on JTAG Connect¶

https://elinux.org/Beagleboard:BeagleBone#Board_Reset_on_JTAG_Connect.28A3.2CA4.2CA5.29

10.5.4. Rebuild drivers from PDK directory¶

Refer Rebuilding the PDK for details on rebuilding the PDK components.

10.6.1. Flash bootable images (C66x, K2H/K2E/K2L only)¶

The Processor SDK RTOS for C6657, C6678, K2H, K2E, and K2L EVMs includes a script in the directory

[SDK Install Path]/processor_sdk_rtos_<platform>_<version>/bin

named program_evm.js. The purpose of this script is to automatically flash bootable images onto your EVM.

The following sections will describe how to use this script and the default flashable binaries in the Processor SDK RTOS.

• A Windows or Linux PC
• Processor SDK RTOS installed on your PC. The version to install must match the SOC you plan to use
• Code Composer Studio installed on your PC
• An USB connection to your EVM emulator

The files used are in the Processor SDK RTOS directory. Expanded below are the relevant files and directories for flashing the bootable images for C667x, but a similar structure is used for C665x.

├── bin
│   ├── configs
│   │   └── evm6678l
│   │       ├── evm6678l.ccxml
│   │       ├── evm6678le.ccxml
│   │       ├── evm6678le-linuxhost.ccxml
│   │       └── evm6678l-linuxhost.ccxml
│   ├── logs
│   └── program_evm.js
└── prebuilt-images
    ├── eeprom50.bin
    ├── eeprom51.bin
    ├── eepromwriter_evm6678l.out
    ├── eepromwriter_input50.txt
    ├── eepromwriter_input51.txt
    ├── eepromwriter_input.txt
    ├── nandwriter_evm6678l.out
    ├── nand_writer_input.txt
    ├── norwriter_evm6678l.out
    └── nor_writer_input.txt

Below is the expanded tree for K2H. Similarly, this also applies to K2E and K2L EVMs.

├── bin
│   ├── configs
│   │   └── evmk2h
│   │       ├── evmk2h.ccxml
│   │       ├── evmk2h-linuxhost.ccxml
│   │       └── program_evm_config
│   ├── logs
│   └── program_evm.js
└── prebuilt-images
    ├── app
    ├── config
    ├── MLO
    └── spi_flash_writer.out

Processor SDK RTOS provides the basic CCXML files to connect to your SOC. There is a separate CCXML file for each SOC, emulator, and host OS combination. These CCXML files are located in:

[SDK Install Path]/processor_sdk_rtos_<platform>_<version>/bin/config/<SOC>

Users can choose to use their own CCXML file by setting the environment variable, PROGRAM_EVM_TARGET_CONFIG_FILE, to point to their CCXML file in their terminal or command prompt.

You can create your own CCXML file by opening CCSv6 –> View –> Target Configurations, and right-clicking on the Target Configuration pane to select New Target Configuration. After selecting your SOC and emulator, remember to set the appropriate GEL file in the advance options for Core 0. The GEL file is used to do basic SOC initialization upon connecting to the core.

Processor SDK RTOS also provides the basic binaries needed to perform flashing. These are separated into two categories - flashwriters and flash images.

Flashwriters

• [C66x] eepromwriter_<SOC>.out - writes content to your EVM EEPROM flash memory
• [C66x] norwriter_<SOC>.out - writes content to your EVM NOR flash memory
• [C66x] nandwriter_<SOC>.out - writes content to your EVM NAND flash memory
• [K2H/E/L] spi_flash_writer.out - writes multiple images to your NOR flash memory

Flash images

• [C66x] eeprom50.bin - eeprom binary for address 0x50. The default for C66x is the POST application.
• [C66x] eeprom51.bin - eeprom binary for address 0x51. The default for C66x is the Intermediate Boot Loader (IBL).
• [C66x] nor.bin - nor binary to be used for NOR boot. May not be provided for every EVM or release version.
• [C66x] nand.bin - nand binary to be used for NAND boot. May not be provided for every EVM or release version.
• [K2H/K2E/K2L] app - NOR binary to be booted by Secondary Bootloader. The default for Keystone 2 is the POST application
• [K2H/K2E/K2L] MLO - Secondary Bootloader. The default flash location is in SPI NOR flash memory at offset 0.

For Windows users:

> cd [SDK Install Path]\processor_sdk_rtos_<platform>_<version>\bin
> set DSS_SCRIPT_DIR=[CCS Install Path]\ccsv6\ccs_base\scripting\bin
> %DSS_SCRIPT_DIR%\dss.bat program_evm.js [tmdx|tmds]evm(6678|6657|k2h|k2e|k2l)[l|le|ls][-le|-be]

For Linux users:

> cd [SDK Install Path]/processor_sdk_rtos_<platform>_<version>/bin
> export DSS_SCRIPT_DIR=[CCS Install Path]/ccsv6/ccs_base/scripting/bin
> $DSS_SCRIPT_DIR/dss.sh program_evm.js [tmdx|tmds]evm(6678|6657|k2h|k2e|k2l)[l|le|ls][-le|-be]

The last argument depends on the SOC that you have, concatenated with the options to select emulator and endianness:

• l: EVM uses XDS100 on-board Emulator
• le: EVM uses 560 Mezzanine Emulator daughter card
• ls: EVM uses XDS200 Emulator card
• -le: Little Endian
• -be: Big Endian

Some examples are:

TMDXEVM6678LE little endian

> $DSS_SCRIPT_DIR/dss.sh program_evm.js tmdxevm6678le-le

TMDSEVM6657LS little endian

> $DSS_SCRIPT_DIR/dss.sh program_evm.js tmdxevm6657ls-le

EVMK2H little endian

> $DSS_SCRIPT_DIR/dss.sh program_evm.js tmdsevmk2h

EVMK2E little endian

> $DSS_SCRIPT_DIR/dss.sh program_evm.js tmdsevmk2e

C:\ti\processor_sdk_rtos_c665x_2_00_01_07\bin>%DSS_SCRIPT_DIR%\dss.bat program_evm.js tmdxevm6657ls-le
board: evm6657l
endian: Little
emulation: XDS200 emulator
binaries: ../prebuilt-images/
ccxml: C:\ti\processor_sdk_rtos_c665x_2_00_01_07\bin/configs/evm6657l/evm6657ls.ccxml
C66xx_0: GEL Output:
Connecting Target...

C66xx_0: GEL Output: DSP core #0

C66xx_0: GEL Output: C6657L GEL file Ver is 1.006

C66xx_0: GEL Output: Global Default Setup...

C66xx_0: GEL Output: Setup Cache...

C66xx_0: GEL Output: L1P = 32K

C66xx_0: GEL Output: L1D = 32K

C66xx_0: GEL Output: L2 = ALL SRAM

C66xx_0: GEL Output: Setup Cache... Done.

C66xx_0: GEL Output: Main PLL (PLL1) Setup ...

C66xx_0: GEL Output: PLL in Bypass ...

C66xx_0: GEL Output: PLL1 Setup for DSP @ 1000.0 MHz.

C66xx_0: GEL Output:            SYSCLK2 = 333.3333 MHz, SYSCLK5 = 200.0 MHz.

C66xx_0: GEL Output:            SYSCLK8 = 15.625 MHz.

C66xx_0: GEL Output: PLL1 Setup... Done.

C66xx_0: GEL Output: Power on all PSC modules and DSP domains...

C66xx_0: GEL Output: Set_PSC_State... Timeout Error #03 pd=12, md=4!

C66xx_0: GEL Output: Power on all PSC modules and DSP domains... Done.

C66xx_0: GEL Output: DDR3 PLL (PLL2) Setup ...

C66xx_0: GEL Output: DDR3 PLL Setup... Done.

C66xx_0: GEL Output: DDR3 Init begin (1333 auto)

C66xx_0: GEL Output: XMC Setup ... Done

C66xx_0: GEL Output: IFRDY bit is SET: DDR3 Interface Ready

C66xx_0: GEL Output:
DDR3 initialization is complete.

C66xx_0: GEL Output: DDR3 Init done

C66xx_0: GEL Output: DDR3 memory test... Started

C66xx_0: GEL Output: DDR3 memory test... Passed

C66xx_0: GEL Output: PLL and DDR3 Initialization completed(0) ...

C66xx_0: GEL Output: configSGMIISerdes Setup... Begin

C66xx_0: GEL Output: SGMII SERDES has been configured.

C66xx_0: GEL Output: Enabling EDC ...

C66xx_0: GEL Output: L1P error detection logic is enabled.

C66xx_0: GEL Output: L2 error detection/correction logic is enabled.

C66xx_0: GEL Output: MSMC error detection/correction logic is enabled.

C66xx_0: GEL Output: Enabling EDC ...Done

C66xx_0: GEL Output: Global Default Setup... Done.

Start writing eeprom50
Writer:../prebuilt-images/eepromwriter_evm6657l.out

Image:../prebuilt-images/eeprom50.bin

C66xx_0: GEL Output: Invalidate All Cache...

C66xx_0: GEL Output: Invalidate All Cache... Done.

C66xx_0: GEL Output: GEL Reset...

C66xx_0: GEL Output: GEL Reset... Done.

C66xx_0: GEL Output: Disable all EDMA3 interrupts and events.

EEPROM Writer Utility Version 01.00.00.05

Writing 57432 bytes from DSP memory address 0x0c000000 to EEPROM bus address 0x0050 starting from device address 0x0000
...
Reading 57432 bytes from EEPROM bus address 0x0050 to DSP memory address 0x0c010000 starting from device address 0x0000
...
Verifying data read ...
EEPROM programming completed successfully
Start writing eeprom51
Writer:../prebuilt-images/eepromwriter_evm6657l.out

Image:../prebuilt-images/eeprom51.bin

C66xx_0: GEL Output: Invalidate All Cache...

C66xx_0: GEL Output: Invalidate All Cache... Done.

C66xx_0: GEL Output: GEL Reset...

C66xx_0: GEL Output: GEL Reset... Done.

C66xx_0: GEL Output: Disable all EDMA3 interrupts and events.

EEPROM Writer Utility Version 01.00.00.05

Writing 47888 bytes from DSP memory address 0x0c000000 to EEPROM bus address 0x0051 starting from device address 0x0000
...
Reading 47888 bytes from EEPROM bus address 0x0051 to DSP memory address 0x0c010000 starting from device address 0x0000
...
Verifying data read ...
EEPROM programming completed successfully
Writer:../prebuilt-images/nandwriter_evm6657l.out

NAND:../prebuilt-images/nand.bin

Required NAND files does not exist in ../prebuilt-images/

Writer:../prebuilt-images/norwriter_evm6657l.out

NOR:../prebuilt-images/nor.bin

Required NOR files does not exist in ../prebuilt-images/

In the above example, nothing was flashed to NAND or NOR since there were no nand.bin or nor.bin binaries to flash.

10.7.1. Adding Custom Board_Library Target to Processor SDK RTOS makefiles¶

Refer Creating Board Library with Custom Name

10.7.2. Processor SDK RTOS Porting Guide for AM571x/AM570x Speed Grades¶

The AM57x Family of Processors includes a wide range of operating performance to meet the needs of a number of broad applications. Among these options are a variety of speed grades to meet different performance points. These devices have a number of specialized cores to provide applications specific computation capabilities. These cores can be run at different speeds to fine tune the processor to the needs of the application, power budget, thermal characteristics, etc.

The Processor SDK for RTOS is a software development package provided to speed development by providing a software reference. This package now includes support for then entire AM57x family of processors which can be broken down into the AM572x, AM571x, and AM570x sets of devices or sub-familes. Most of the devices in this family are supported by the Processor SDK for RTOS right out of the box. This support is tested and validated on TI designed EVMs. These EVMs use the highest performance devices in the family in order to allow users to evaluate the entire spectrum of performance.

The AM571X and AM570x supports several lower power speed grades. If one of these devices is being used on the custom board, the GEL file and the board library needs to be changed to account for this difference. If this change is not made, the device could be running out of specification. These changes may reach across other cores and clocks on the device as well, depending on what speeds they need to operate at. This document is not an exhaustive list of all the changes needed for a proper board port as it focused on the changes needed to enable different speed grades.

Quick Feature Set comparison between devices in Sitara AM57xx family :

TI Supports following evaluation platform for AM57xx class of devices:

• AM572x GP EVM
• AM571x IDK
• AM572x IDK

When developer selects any of the above platforms in Code composer Studio, the target configuration automatically brings in the required initialization files and GEL files to configure the clocks, slave cores, external memory.

If you are using a custom platform or AM5708 device that is not available on a TI Evaluation platform, you can follow the steps provided below to connect to the SOC by reusing the GEL files that are provided for TI evaluation platforms. For example, here we demonstrate how you can create a target configuration for AM570x and connect to the device if your board design is based of one of TI evalauation platforms listed below. The assumption here is that the custom board is based off AM571X IDK platform

Step 1: Select the AM570x part number that is populated on your custom platform:

Step 2: Setup the GEL files for the SOC Go to the Advanced Tab as shown in the previous screenshot and update startup GEL file in the A15 Core as shown in the screenshot below

The board library provides setting for OPP_NOM, OPP_OD and OPP_HIGH in the PLL settings using 20 MHz input clock that has been used on the AM572x GP EVM as well as the AM571x IDK platform. This allows customers to setup the MPU to 1.5, 1.176 and 1GHz. For AM570x devices, we support the “J” and the “D” variant which support the following max speeds on the DPLLs:

When using the “J” speed grade, ensure that the DPLLs in the board set the DPLL to OPP_NOM and not for OPP_OD or OPP_HIGH.

To do this, you can invoke the Board_Init from your application using either

Board_initCfg boardCfg;
boardCfg = BOARD_INIT_PLL_OPP_NOM;
boardCfg |= BOARD_INIT_UNLOCK_MMR |
       BOARD_INIT_MODULE_CLOCK |
       BOARD_INIT_PINMUX_CONFIG |
       BOARD_INIT_DDR |
       BOARD_INIT_UART_STDIO |
       BOARD_INIT_WATCHDOG_DISABLE;
/* Board Library Init. */
   Board_init(boardCfg);

When using “D” rated parts that run at 500 MHz, in addition to the above configuration, you will also need to modify OPP_NOM settings in the board library by updating the DPLL setting for MPU and DSP in the file <BoardName>_pll.c as shown below:

Step1 : Update MPU, DSP, IVA and GPU DPLL setting

• MPU DPLL Changes:

/* Default to OPP_NOM */
     /* 500MHz at 20MHz sys_clk */
     mpuPllcParam.mult = 250U;
     mpuPllcParam.div = 9U;
     mpuPllcParam.dccEnable = 0U;
     mpuPllcParam.divM2 = 1U;

• DSP DPLL Changes:

/* 500MHz at 20MHz sys_clk */
dspPllcParam.mult = 130U;
dspPllcParam.div = 3U;
dspPllcParam.divM2 = 1U;
dspPllcParam.divM3 = 3U;

• Remove IVA and GPU PLL settings

Since IVA and GPU modules are not available on the device, we recommend removing the ivaPLL and gpuPLL settings in board.

              /* Default to OPP_NOM */
              /* 388.3MHz at 20MHz sys_clk */
-                ivaPllcParam.mult = 233U;
-                ivaPllcParam.div = 3U;
-                ivaPllcParam.divM2 = 3U;

             /* Default to OPP_NOM */
             /* 425MHz at 20MHz sys_clk */
-                gpuPllcParam.mult = 170U;
-                gpuPllcParam.div = 3U;
-                gpuPllcParam.divM2 = 2U;

Step 2 : Disable clocks configuration and wakeup for IVA in PRCM

• Remove IVA wakeup and Module configuration

The following updates need to be made in the file <BoardName>_clock.c to remove IVA wakeup and clock configuration

-        CSL_FINST(ivaCmReg->CM_IVA_CLKSTCTRL_REG,
-        IVA_CM_CORE_CM_IVA_CLKSTCTRL_REG_CLKTRCTRL, SW_WKUP);

   /* PRCM Specialized module mode setting functions */
-   CSL_FINST(ivaCmReg->CM_IVA_SL2_CLKCTRL_REG,
-       IVA_CM_CORE_CM_IVA_SL2_CLKCTRL_REG_MODULEMODE, AUTO);
-  while(CSL_IVA_CM_CORE_CM_IVA_SL2_CLKCTRL_REG_IDLEST_DISABLE ==
-      CSL_FEXT(ivaCmReg->CM_IVA_SL2_CLKCTRL_REG,
-       IVA_CM_CORE_CM_IVA_SL2_CLKCTRL_REG_IDLEST));
-   CSL_FINST(ivaCmReg->CM_IVA_IVA_CLKCTRL_REG,
-       IVA_CM_CORE_CM_IVA_IVA_CLKCTRL_REG_MODULEMODE, AUTO);
-   while(CSL_IVA_CM_CORE_CM_IVA_IVA_CLKCTRL_REG_IDLEST_DISABLE ==
-      CSL_FEXT(ivaCmReg->CM_IVA_IVA_CLKCTRL_REG,
-       IVA_CM_CORE_CM_IVA_IVA_CLKCTRL_REG_IDLEST));

An important one to consider is the speed of the DDR memory. The clock for the DDR is selected using the same dplls structure. Some higher speed grade parts support a 667 MHz DDR clock, but some of the lower speed grade parts only support a 533 MHz DDR3 clock. Make sure to choose the appropriate DDR clock for the device on the custom board.

Over in the board/src/<BoardName>/<BoardName_ddr>.c file, make sure that the EMIF is being configured correctly for the appropriate speed, and that the appropriate number of EMIFs is being selected to match the part being used. AM572x part has 2 DDR interfaces running at 533 MHz and the AM571x (and AM570x) only have one running at 667 MHz. This code can be kept or removed by the board port. As changes are made, the code must make sure to configure the new board correctly, with the appropriate number of DDR interfaces and speed configuration.

For AM571x and AM570x, make sure to use the code for the AM571x IDK in board/src/<BoardName>/<BoardName_ddr>.c to select 1 EMIF:

/* MA_LISA_MAP_i */
hMampuLsm->MAP_0 = 0x80600100U;
/* DMM_LISA_MAP_i */
hDmmCfg->LISA_MAP[0U] = 0x80600100U;

For AM572x, this is mapped as following

/* MA_LISA_MAP_i */
hMampuLsm->MAP_0 = 0x80740300;
hMampuLsm->MAP_1 = 0x80740300;
/* DMM_LISA_MAP_i */
hDmmCfg->LISA_MAP[0U] = 0x80740300;
hDmmCfg->LISA_MAP[1U] = 0x80740300;

• For part number where the Display subsystem or SATA is not available, the pins can be configured to any other pin functionality that may be required in the system. If you don`t need to use these pins, we recommend that you leave these pins in default MUXMODE and terminate the pinmux as recommended in the Schematics Checklist.
• There is no pinmux setting for CSI2 module so you can leave the MUXMODE=0 on those pins if there is no instance of the peripheral

Some control drivers use default Module input clock frequency settings in <module>_soc.c file that gets used by the Low level drivers to configure the peripheral clocks. The default module input clock frequency is set to the OPP_NOM values that are available on the superset variant of the device so if you are using lower speed grades. Ensure you change the default to match the module clock on the 500 MHz settings or you can use the following sequence to update the settings. Code below describes how the SPI driver module input clock frequency can be modified

SPI_v1_HWAttrs spi_cfg;
/* Get the default SPI init configurations */
SPI_socGetInitCfg(TEST_SPI_PORT, &spi_cfg);
/* Modify the default SPI configurations if necessary */
spi_cfg.inputClkFreq = 24000000;
/* Set the default SPI init configurations */
SPI_socSetInitCfg(TEST_SPI_PORT, &spi_cfg);

• Linux_Porting_Guide_for_AM571x/AM570x_Speed_Grades

Useful Utilities

• Clock Tree Tool
• Pin Mux tool

For any questions related Usage of AM572x, AM571x and AM570x devices, please post your question on TI E2E Forums

• TI E2E Forums for Sitara Processors

10.8.1. Create DSP and IPU firmware using PDK drivers and IPC to load from ARM Linux on AM57xx devices¶

This article is geared toward AM57xx users that are running Linux on the Cortex A15. The goal is to help users understand how to gain entitlement to the DSP (c66x) and IPU (Cortex M4) subsystems of the AM57xx.

AM572x device has two IPU subsystems (IPUSS), each of which has 2 cores. IPU2 is used as a controller in multi-media applications, so if you have Processor SDK Linux running, chances are that IPU2 already has firmware loaded. However, IPU1 is open for general purpose programming to offload the ARM tasks.

There are many facets to this task: building, loading, debugging, MMUs, memory sharing, etc. This article intends to take incremental steps toward understanding all of those pieces.

Software Dependencies to Get Started

Prerequisites

• Processor SDK Linux for AM57xx (Version 3.01 or newer needed)
• Processor SDK RTOS for AM57xx
• Code Composer Studio (choose version as specified on Proc SDK download page)

For reference within the context of this wiki page, the Linux SDK is installed at the following location:

/mnt/data/user/ti-processor-sdk-linux-am57xx-evm-xx.xx.xx.xx
├── bin
├── board-support
├── docs
├── example-applications
├── filesystem
├── ipc-build.txt
├── linux-devkit
├── Makefile
├── Rules.make
└── setup.sh

The RTOS SDK is installed at:

/mnt/data/user/my_custom_install_sdk_rtos_am57xx_xx.xx
├── bios_6_xx_xx_xx
├── cg_xml
├── ctoolslib_x_x_x_x
├── dsplib_c66x_x_x_x_x
├── edma3_lld_2_xx_xx_xx
├── framework_components_x_xx_xx_xx
├── imglib_c66x_x_x_x_x
├── ipc_3_xx_xx_xx
├── mathlib_c66x_3_x_x_x
├── ndk_2_xx_xx_xx
├── opencl_rtos_am57xx_01_01_xx_xx
├── openmp_dsp_am57xx_2_04_xx_xx
├── pdk_am57xx_x_x_x
├── processor_sdk_rtos_am57xx_x_xx_xx_xx
├── uia_2_xx_xx_xx
├── xdais_7_xx_xx_xx

CCS is installed at:

/mnt/data/user/ti/my_custom_ccs_x.x.x_install
├── ccsvX
│   ├── ccs_base
│   ├── doc
│   ├── eclipse
│   ├── install_info
│   ├── install_logs
│   ├── install_scripts
│   ├── tools
│   ├── uninstall_ccs
│   ├── uninstall_ccs.dat
│   ├── uninstallers
│   └── utils
├── Code Composer Studio x.x.x.desktop
└── xdctools_x_xx_xx_xx_core
    ├── bin
    ├── config.jar
    ├── docs
    ├── eclipse
    ├── etc
    ├── gmake
    ├── include
    ├── package
    ├── packages
    ├── package.xdc
    ├── tconfini.tcf
    ├── xdc
    ├── xdctools_3_xx_xx_xx_manifest.html
    ├── xdctools_3_xx_xx_xx_release_notes.html
    ├── xs
    └── xs.x86U

Typical Boot Flow on AM572x for ARM Linux users

AM57xx SOC’s have multiple processor cores - Cortex A15, C66x DSP’s and ARM M4 cores. The A15 typically runs a HLOS like Linux/QNX/Android and the remotecores(DSP’s and M4’s) run a RTOS. In the normal operation, boot loader(U-Boot/SPL) boots and loads the A15 with the HLOS. The A15 boots the DSP and the M4 cores.

In this sequence, the interval between the Power on Reset and the remotecores (i.e. the DSP’s and the M4’s) executing is dependent on the HLOS initialization time.

The figure below illustrates how remoteproc/rpmsg driver from ARM Linux kernel communicates with IPC driver on slave processor (e.g. DSP, IPU, etc) running RTOS.

In order to setup IPC on slave cores, we provide some pre-built examples in IPC package that can be run from ARM Linux. The subsequent sections describe how to build and run this examples and use that as a starting point for this effort.

Building the Bundled IPC Examples

The instructions to build IPC examples found under ipc_3_xx_xx_xx/examples/DRA7XX_linux_elf have been provided in the `Processor_SDK IPC Quick Start Guide <https://processors.wiki.ti.com/index.php/Processor_SDK_IPC_Quick_Start_Guide#Build_IPC_Linux_examples>`__.

Let’s focus on one example in particular, ex02_messageq, which is located at <rtos-sdk-install-dir>/ipc_3_xx_xx_xx/examples/DRA7XX_linux_elf/ex02_messageq. Here are the key files that you should see after a successful build:

├── dsp1
│   └── bin
│       ├── debug
│       │   └── server_dsp1.xe66
│       └── release
│           └── server_dsp1.xe66
├── dsp2
│   └── bin
│       ├── debug
│       │   └── server_dsp2.xe66
│       └── release
│           └── server_dsp2.xe66
├── host
│       ├── debug
│       │   └── app_host
│       └── release
│           └── app_host
├── ipu1
│   └── bin
│       ├── debug
│       │   └── server_ipu1.xem4
│       └── release
│           └── server_ipu1.xem4
└── ipu2
    └── bin
        ├── debug
        │   └── server_ipu2.xem4
        └── release
            └── server_ipu2.xem4

Running the Bundled IPC Examples

On the target, let’s create a directory called ipc-starter:

root@am57xx-evm:~# mkdir -p /home/root/ipc-starter
root@am57xx-evm:~# cd /home/root/ipc-starter/

You will need to copy the ex02_messageq directory of your host PC to that directory on the target (through SD card, NFS export, SCP, etc.). You can copy the entire directory, though we’re primarily interested in these files:

• dsp1/bin/debug/server_dsp1.xe66
• dsp2/bin/debug/server_dsp2.xe66
• host/bin/debug/app_host
• ipu1/bin/debug/server_ipu1.xem4
• ipu2/bin/debug/server_ipu2.xem4

The remoteproc driver is hard-coded to look for specific files when loading the DSP/M4. Here are the files it looks for:

• /lib/firmware/dra7-dsp1-fw.xe66
• /lib/firmware/dra7-dsp2-fw.xe66
• /lib/firmware/dra7-ipu1-fw.xem4
• /lib/firmware/dra7-ipu2-fw.xem4

These are generally a soft link to the intended executable. So for example, let’s update the DSP1 executable on the target:

root@am57xx-evm:~# cd /lib/firmware/
root@am57xx-evm:/lib/firmware# rm dra7-dsp1-fw.xe66
root@am57xx-evm:/lib/firmware# ln -s /home/root/ipc-starter/ex02_messageq/dsp1/bin/debug/server_dsp1.xe66 dra7-dsp1-fw.xe66

To reload DSP1 with this new executable, we perform the following steps:

root@am57xx-evm:/lib/firmware# cd /sys/bus/platform/drivers/omap-rproc/
root@am57xx-evm:/sys/bus/platform/drivers/omap-rproc# echo 40800000.dsp > unbind
[27639.985631] omap_hwmod: mmu0_dsp1: _wait_target_disable failed
[27639.991534] omap-iommu 40d01000.mmu: 40d01000.mmu: version 3.0
[27639.997610] omap-iommu 40d02000.mmu: 40d02000.mmu: version 3.0
[27640.017557] omap_hwmod: mmu1_dsp1: _wait_target_disable failed
[27640.030571] omap_hwmod: mmu0_dsp1: _wait_target_disable failed
[27640.036605]  remoteproc2: stopped remote processor 40800000.dsp
[27640.042805]  remoteproc2: releasing 40800000.dsp
root@am57xx-evm:/sys/bus/platform/drivers/omap-rproc# echo 40800000.dsp > bind
[27645.958613] omap-rproc 40800000.dsp: assigned reserved memory node dsp1_cma@99000000
[27645.966452]  remoteproc2: 40800000.dsp is available
[27645.971410]  remoteproc2: Note: remoteproc is still under development and considered experimental.
[27645.980536]  remoteproc2: THE BINARY FORMAT IS NOT YET FINALIZED, and backward compatibility isn't yet guaranteed.
root@am57xx-evm:/sys/bus/platform/drivers/omap-rproc# [27646.008171]  remoteproc2: powering up 40800000.dsp
[27646.013038]  remoteproc2: Booting fw image dra7-dsp1-fw.xe66, size 4706800
[27646.028920] omap_hwmod: mmu0_dsp1: _wait_target_disable failed
[27646.034819] omap-iommu 40d01000.mmu: 40d01000.mmu: version 3.0
[27646.040772] omap-iommu 40d02000.mmu: 40d02000.mmu: version 3.0
[27646.058323]  remoteproc2: remote processor 40800000.dsp is now up
[27646.064772] virtio_rpmsg_bus virtio2: rpmsg host is online
[27646.072271]  remoteproc2: registered virtio2 (type 7)
[27646.078026] virtio_rpmsg_bus virtio2: creating channel rpmsg-proto addr 0x3d

More info related to loading firmware to the various cores can be found here.

Finally, we can run the example on DSP1:

root@am57xx-evm:/sys/bus/platform/drivers/omap-rproc# cd /home/root/ipc-starter/ex02_messageq/host/bin/debug
root@am57xx-evm:~/ipc-starter/ex02_messageq/host/bin/debug# ./app_host DSP1
--> main:
[33590.700700] omap_hwmod: mmu0_dsp2: _wait_target_disable failed
[33590.706609] omap-iommu 41501000.mmu: 41501000.mmu: version 3.0
[33590.718798] omap-iommu 41502000.mmu: 41502000.mmu: version 3.0
--> Main_main:
--> App_create:
App_create: Host is ready
<-- App_create:
--> App_exec:
App_exec: sending message 1
App_exec: sending message 2
App_exec: sending message 3
App_exec: message received, sending message 4
App_exec: message received, sending message 5
App_exec: message received, sending message 6
App_exec: message received, sending message 7
App_exec: message received, sending message 8
App_exec: message received, sending message 9
App_exec: message received, sending message 10
App_exec: message received, sending message 11
App_exec: message received, sending message 12
App_exec: message received, sending message 13
App_exec: message received, sending message 14
App_exec: message received, sending message 15
App_exec: message received
App_exec: message received
App_exec: message received
<-- App_exec: 0
--> App_delete:
<-- App_delete:
<-- Main_main:
<-- main:

The similar procedure can be used for DSP2/IPU1/IPU2 also to update the soft link of the firmware, reload the firmware at run-time, and run the host binary from A15.

Overall Linux Memory Map

root@am57xx-evm:~# cat /proc/iomem
[snip...]
58060000-58078fff : core
58820000-5882ffff : l2ram
58882000-588820ff : /ocp/mmu@58882000
80000000-9fffffff : System RAM
80008000-808d204b : Kernel code
80926000-809c96bf : Kernel data
a0000000-abffffff : CMEM
ac000000-ffcfffff : System RAM

CMA Carveouts

root@am57xx-evm:~# dmesg | grep -i cma
[    0.000000] Reserved memory: created CMA memory pool at 0x0000000095800000, size 56 MiB
[    0.000000] Reserved memory: initialized node ipu2_cma@95800000, compatible id shared-dma-pool
[    0.000000] Reserved memory: created CMA memory pool at 0x0000000099000000, size 64 MiB
[    0.000000] Reserved memory: initialized node dsp1_cma@99000000, compatible id shared-dma-pool
[    0.000000] Reserved memory: created CMA memory pool at 0x000000009d000000, size 32 MiB
[    0.000000] Reserved memory: initialized node ipu1_cma@9d000000, compatible id shared-dma-pool
[    0.000000] Reserved memory: created CMA memory pool at 0x000000009f000000, size 8 MiB
[    0.000000] Reserved memory: initialized node dsp2_cma@9f000000, compatible id shared-dma-pool
[    0.000000] cma: Reserved 24 MiB at 0x00000000fe400000
[    0.000000] Memory: 1713468K/1897472K available (6535K kernel code, 358K rwdata, 2464K rodata, 332K init, 289K bss, 28356K reserved, 155648K  cma-reserved, 1283072K highmem)
[    5.492945] omap-rproc 58820000.ipu: assigned reserved memory node ipu1_cma@9d000000
[    5.603289] omap-rproc 55020000.ipu: assigned reserved memory node ipu2_cma@95800000
[    5.713411] omap-rproc 40800000.dsp: assigned reserved memory node dsp1_cma@9b000000
[    5.771990] omap-rproc 41000000.dsp: assigned reserved memory node dsp2_cma@9f000000

From the output above, we can derive the location and size of each CMA carveout:

For details on how to adjust the sizes and locations of the DSP/IPU CMA carveouts, please see the corresponding section for changing the DSP or IPU memory map.

To adjust the size of the “Default CMA” section, this is done as part of the Linux config:

linux/arch/arm/configs/tisdk_am57xx-evm_defconfig

#
# Default contiguous memory area size:
#
CONFIG_CMA_SIZE_MBYTES=24
CONFIG_CMA_SIZE_SEL_MBYTES=y

CMEM

To view the allocation at run-time:

root@am57xx-evm:~# cat /proc/cmem

Block 0: Pool 0: 1 bufs size 0xc000000 (0xc000000 requested)

Pool 0 busy bufs:

Pool 0 free bufs:
id 0: phys addr 0xa0000000

This shows that we have defined a CMEM block at physical base address of 0xA0000000 with total size 0xc000000 (192 MB). This block contains a buffer pool consisting of 1 buffer. Each buffer in the pool (only one in this case) is defined to have a size of 0xc000000 (192 MB).

Here is where those sizes/addresses were defined for the AM57xx EVM:

linux/arch/arm/boot/dts/am57xx-evm-cmem.dtsi

{
       reserved-memory {
               #address-cells = <2>;
               #size-cells = <2>;
               ranges;

               cmem_block_mem_0: cmem_block_mem@a0000000 {
                       reg = <0x0 0xa0000000 0x0 0x0c000000>;
                       no-map;
                       status = "okay";
               };

               cmem_block_mem_1_ocmc3: cmem_block_mem@40500000 {
                       reg = <0x0 0x40500000 0x0 0x100000>;
                       no-map;
                       status = "okay";
               };
       };

       cmem {
               compatible = "ti,cmem";
               #address-cells = <1>;
               #size-cells = <0>;

               #pool-size-cells = <2>;

               status = "okay";

               cmem_block_0: cmem_block@0 {
                       reg = <0>;
                       memory-region = <&cmem_block_mem_0>;
                       cmem-buf-pools = <1 0x0 0x0c000000>;
               };

               cmem_block_1: cmem_block@1 {
                       reg = <1>;
                       memory-region = <&cmem_block_mem_1_ocmc3>;
               };
       };
};

Changing the DSP Memory Map

First, it is important to understand that there are a pair of Memory Management Units (MMUs) that sit between the DSP subsystems and the L3 interconnect. One of these MMUs is for the DSP core and the other is for its local EDMA. They both serve the same purpose of translating virtual addresses (i.e. the addresses as viewed by the DSP subsystem) into physical addresses (i.e. addresses as viewed from the L3 interconnect).

DSP Physical Addresses

The physical location where the DSP code/data will actually reside is defined by the CMA carveout. To change this location, you must change the definition of the carveout. The DSP carveouts are defined in the Linux dts file. For example for the AM57xx EVM:

linux/arch/arm/boot/dts/am57xx-beagle-x15-common.dtsi

{
        dsp1_cma_pool: dsp1_cma@99000000 {
                compatible = "shared-dma-pool";
                reg = <0x0 0x99000000 0x0 0x4000000>;
                reusable;
                status = "okay";
        };

        dsp2_cma_pool: dsp2_cma@9f000000 {
                compatible = "shared-dma-pool";
                reg = <0x0 0x9f000000 0x0 0x800000>;
                reusable;
                status = "okay";
        };
};

You are able to change both the size and location. Be careful not to overlap any other carveouts!

Additionally, when you change the carveout location, there is a corresponding change that must be made to the resource table. For starters, if you’re making a memory change you will need a custom resource table. The resource table is a large structure that is the “bridge” between physical memory and virtual memory. This structure is utilized for configuring the MMUs that sit in front of the DSP subsystem. There is detailed information available in the article IPC Resource customTable.

Once you’ve created your custom resource table, you must update the address of PHYS_MEM_IPC_VRING to be the same base address as your corresponding CMA.

#if defined (VAYU_DSP_1)
#define PHYS_MEM_IPC_VRING      0x99000000
#elif defined (VAYU_DSP_2)
#define PHYS_MEM_IPC_VRING      0x9F000000
#endif

DSP Virtual Addresses

These addresses are the ones seen by the DSP subsystem, i.e. these will be the addresses in your linker command files, etc.

You must ensure that the sizes of your sections are consistent with the corresponding definitions in the resource table. You should create your own resource table in order to modify the memory map. This is describe in the wiki page IPC Resource customTable. You can look at an existing resource table inside IPC:

ipc/packages/ti/ipc/remoteproc/rsc_table_vayu_dsp.h

{
    TYPE_CARVEOUT,
    DSP_MEM_TEXT, 0,
    DSP_MEM_TEXT_SIZE, 0, 0, "DSP_MEM_TEXT",
},

{
    TYPE_CARVEOUT,
    DSP_MEM_DATA, 0,
    DSP_MEM_DATA_SIZE, 0, 0, "DSP_MEM_DATA",
},

{
    TYPE_CARVEOUT,
    DSP_MEM_HEAP, 0,
    DSP_MEM_HEAP_SIZE, 0, 0, "DSP_MEM_HEAP",
},

{
    TYPE_CARVEOUT,
    DSP_MEM_IPC_DATA, 0,
    DSP_MEM_IPC_DATA_SIZE, 0, 0, "DSP_MEM_IPC_DATA",
},

{
    TYPE_TRACE, TRACEBUFADDR, 0x8000, 0, "trace:dsp",
},


{
    TYPE_DEVMEM,
    DSP_MEM_IPC_VRING, PHYS_MEM_IPC_VRING,
    DSP_MEM_IPC_VRING_SIZE, 0, 0, "DSP_MEM_IPC_VRING",
},

Let’s have a look at some of these to understand them better. For example:

{
    TYPE_CARVEOUT,
    DSP_MEM_TEXT, 0,
    DSP_MEM_TEXT_SIZE, 0, 0, "DSP_MEM_TEXT",
},

Key points to note are:

1. The “TYPE_CARVEOUT” indicates that the physical memory backing this entry will come from the associated CMA pool.
2. DSP_MEM_TEXT is a #define earlier in the code providing the address for the code section. It is 0x95000000 by default. This must correspond to a section from your DSP linker command file, i.e. EXT_CODE (or whatever name you choose to give it) must be linked to the same address.
3. DSP_MEM_TEXT_SIZE is the size of the MMU pagetable entry being created (1MB in this particular instance). The actual amount of linked code in the corresponding section of your executable must be less than or equal to this size.

Let’s take another:

{
    TYPE_TRACE, TRACEBUFADDR, 0x8000, 0, "trace:dsp",
},

Key points are:

1. The “TYPE_TRACE” indicates this is for trace info.
2. The TRACEBUFADDR is defined earlier in the file as &ti_trace_SysMin_Module_State_0_outbuf__A. That corresponds to the symbol used in TI-RTOS for the trace buffer.
3. The “0x8000” is the size of the MMU mapping. The corresponding size in the cfg file should be the same (or less). It looks like this: SysMin.bufSize  = 0x8000;

Finally, let’s look at a TYPE_DEVMEM example:

{
    TYPE_DEVMEM,
    DSP_PERIPHERAL_L4CFG, L4_PERIPHERAL_L4CFG,
    SZ_16M, 0, 0, "DSP_PERIPHERAL_L4CFG",
},

Key points:

1. The “TYPE_DEVMEM” indicates that we are making an MMU mapping, but this does not come from the CMA pool. This is intended for mapping peripherals, etc. that already exist in the device memory map.
2. DSP_PERIPHERAL_L4CFG (0x4A000000) is the virtual address while L4_PERIPHERAL_L4CFG (0x4A000000) is the physical address. This is an identity mapping, meaning that peripherals can be referenced by the DSP using their physical address.

DSP Access to Peripherals

The default resource table creates the following mappings:

In other words, the peripherals can be accessed at their physical addresses since we use an identity mapping.

Inspecting the DSP IOMMU Page Tables at Run-Time

You can dump the DSP IOMMU page tables with the following commands:

In general, MMU0 and MMU1 are being programmed identically so you really only need to take a look at one or the other to understand the mapping for a given DSP.

For example:

root@am57xx-evm:~# cat /sys/kernel/debug/omap_iommu/40d01000.mmu/pagetable
L:      da:     pte:
--------------------------
1: 0x48000000 0x48000002
1: 0x48100000 0x48100002
1: 0x48400000 0x48400002
1: 0x48500000 0x48500002
1: 0x48600000 0x48600002
1: 0x48700000 0x48700002
1: 0x48800000 0x48800002
1: 0x48900000 0x48900002
1: 0x48a00000 0x48a00002
1: 0x48b00000 0x48b00002
1: 0x48c00000 0x48c00002
1: 0x48d00000 0x48d00002
1: 0x48e00000 0x48e00002
1: 0x48f00000 0x48f00002
1: 0x4a000000 0x4a040002
1: 0x4a100000 0x4a040002
1: 0x4a200000 0x4a040002
1: 0x4a300000 0x4a040002
1: 0x4a400000 0x4a040002
1: 0x4a500000 0x4a040002
1: 0x4a600000 0x4a040002
1: 0x4a700000 0x4a040002
1: 0x4a800000 0x4a040002
1: 0x4a900000 0x4a040002
1: 0x4aa00000 0x4a040002
1: 0x4ab00000 0x4a040002
1: 0x4ac00000 0x4a040002
1: 0x4ad00000 0x4a040002
1: 0x4ae00000 0x4a040002
1: 0x4af00000 0x4a040002

The first column tells us whether the mapping is a Level 1 or Level 2 descriptor. All the lines above are a first level descriptor, so we look at the associated format from the TRM:

The “da” (“device address”) column reflects the virtual address. It is derived from the index into the table, i.e. there does not exist a “da” register or field in the page table. Each MB of the address space maps to an entry in the table. The “da” column is displayed to make it easy to find the virtual address of interest.

The “pte” (“page table entry”) column can be decoded according to Table 20-4 shown above. For example:

1: 0x4a000000 0x4a040002

The 0x4a040002 shows us that it is a Supersection with base address 0x4A000000. This gives us a 16 MB memory page. Note the repeated entries afterward. That’s a requirement of the MMU. Here’s an excerpt from the TRM:

Changing Cortex M4 IPU Memory Map

In order to fully understand the memory mapping of the Cortex M4 IPU Subsystems, it’s helpful to recognize that there are two distinct/independent levels of memory translation. Here’s a snippet from the TRM to illustrate:

Cortex M4 IPU Physical Addresses

The physical location where the M4 code/data will actually reside is defined by the CMA carveout. To change this location, you must change the definition of the carveout. The M4 carveouts are defined in the Linux dts file. For example for the AM57xx EVM:

linux/arch/arm/boot/dts/am57xx-beagle-x15-common.dtsi

{
        ipu2_cma_pool: ipu2_cma@95800000 {
                compatible = "shared-dma-pool";
                reg = <0x0 95800000 0x0 0x3800000>;
                reusable;
                status = "okay";
        };

        ipu1_cma_pool: ipu1_cma@9d000000 {
                compatible = "shared-dma-pool";
                reg = <0x0 9d000000 0x0 0x2000000>;
                reusable;
                status = "okay";
        };
};

You are able to change both the size and location. Be careful not to overlap any other carveouts!

Additionally, when you change the carveout location, there is a corresponding change that must be made to the resource table. For starters, if you’re making a memory change you will need a custom resource table. The resource table is a large structure that is the “bridge” between physical memory and virtual memory. This structure is utilized for configuring the IPUx_MMU (not the Unicache MMU). There is detailed information available in the article IPC Resource customTable.

Once you’ve created your custom resource table, you must update the address of PHYS_MEM_IPC_VRING to be the same base address as your corresponding CMA.

#if defined(VAYU_IPU_1)
#define PHYS_MEM_IPC_VRING      0x9D000000
#elif defined (VAYU_IPU_2)
#define PHYS_MEM_IPC_VRING      0x95800000
#endif

Cortex M4 IPU Virtual Addresses

Unicache MMU

The Unicache MMU sits closest to the Cortex M4. It provides the first level of address translation. The Unicache MMU is actually “self programmed” by the Cortex M4. The Unicache MMU is also referred to as the Attribute MMU (AMMU). There are a fixed number of small, medium and large pages. Here’s a snippet showing some of the key mappings:

ipc_3_43_02_04/examples/DRA7XX_linux_elf/ex02_messageq/ipu1/IpuAmmu.cfg

/*********************** Large Pages *************************/
/* Instruction Code: Large page  (512M); cacheable */
/* config large page[0] to map 512MB VA 0x0 to L3 0x0 */
AMMU.largePages[0].pageEnabled = AMMU.Enable_YES;
AMMU.largePages[0].logicalAddress = 0x0;
AMMU.largePages[0].translationEnabled = AMMU.Enable_NO;
AMMU.largePages[0].size = AMMU.Large_512M;
AMMU.largePages[0].L1_cacheable = AMMU.CachePolicy_CACHEABLE;
AMMU.largePages[0].L1_posted = AMMU.PostedPolicy_POSTED;

/* Peripheral regions: Large Page (512M); non-cacheable */
/* config large page[1] to map 512MB VA 0x60000000 to L3 0x60000000 */
AMMU.largePages[1].pageEnabled = AMMU.Enable_YES;
AMMU.largePages[1].logicalAddress = 0x60000000;
AMMU.largePages[1].translationEnabled = AMMU.Enable_NO;
AMMU.largePages[1].size = AMMU.Large_512M;
AMMU.largePages[1].L1_cacheable = AMMU.CachePolicy_NON_CACHEABLE;
AMMU.largePages[1].L1_posted = AMMU.PostedPolicy_POSTED;

/* Private, Shared and IPC Data regions: Large page (512M); cacheable */
/* config large page[2] to map 512MB VA 0x80000000 to L3 0x80000000 */
AMMU.largePages[2].pageEnabled = AMMU.Enable_YES;
AMMU.largePages[2].logicalAddress = 0x80000000;
AMMU.largePages[2].translationEnabled = AMMU.Enable_NO;
AMMU.largePages[2].size = AMMU.Large_512M;
AMMU.largePages[2].L1_cacheable = AMMU.CachePolicy_CACHEABLE;
AMMU.largePages[2].L1_posted = AMMU.PostedPolicy_POSTED;

These 3 pages are “identity” mappings, performing a passthrough of requests to the associated address ranges. These intermediate addresses get mapped to their physical addresses in the next level of translation (IOMMU).

The AMMU ranges for code and data need to be identity mappings because otherwise the remoteproc loader wouldn’t be able to match up the sections from the ELF file with the associated IOMMU mapping. These mappings should suffice for any application, i.e. no need to adjust these. The more likely area for modification is the resource table in the next section. The AMMU mappings are needed mainly to understand the full picture with respect to the Cortex M4 memory map.

IOMMU

The IOMMU sits closest to the L3 interconnect. It takes the intermediate address output from the AMMU and translates it to the physical address used by the L3 interconnect. The IOMMU is programmed by the ARM based on the associated resource table. If you’re planning any memory changes then you’ll want to make a custom resource table as described in the wiki page IPC Resource customTable.

The default resource table (which can be adapted to make a custom table) can be found at this location:

ipc/packages/ti/ipc/remoteproc/rsc_table_vayu_ipu.h

#define IPU_MEM_TEXT            0x0
#define IPU_MEM_DATA            0x80000000

#define IPU_MEM_IOBUFS          0x90000000

#define IPU_MEM_IPC_DATA        0x9F000000
#define IPU_MEM_IPC_VRING       0x60000000
#define IPU_MEM_RPMSG_VRING0    0x60000000
#define IPU_MEM_RPMSG_VRING1    0x60004000
#define IPU_MEM_VRING_BUFS0     0x60040000
#define IPU_MEM_VRING_BUFS1     0x60080000

#define IPU_MEM_IPC_VRING_SIZE  SZ_1M
#define IPU_MEM_IPC_DATA_SIZE   SZ_1M

#if defined(VAYU_IPU_1)
#define IPU_MEM_TEXT_SIZE       (SZ_1M)
#elif defined(VAYU_IPU_2)
#define IPU_MEM_TEXT_SIZE       (SZ_1M * 6)
#endif

#if defined(VAYU_IPU_1)
#define IPU_MEM_DATA_SIZE       (SZ_1M * 5)
#elif defined(VAYU_IPU_2)
#define IPU_MEM_DATA_SIZE       (SZ_1M * 48)
#endif

<snip...>

{
    TYPE_CARVEOUT,
    IPU_MEM_TEXT, 0,
    IPU_MEM_TEXT_SIZE, 0, 0, "IPU_MEM_TEXT",
},

{
    TYPE_CARVEOUT,
    IPU_MEM_DATA, 0,
    IPU_MEM_DATA_SIZE, 0, 0, "IPU_MEM_DATA",
},

{
    TYPE_CARVEOUT,
    IPU_MEM_IPC_DATA, 0,
    IPU_MEM_IPC_DATA_SIZE, 0, 0, "IPU_MEM_IPC_DATA",
},

The 3 entries above from the resource table all come from the associated IPU CMA pool (i.e. as dictated by the TYPE_CARVEOUT). The second parameter represents the virtual address (i.e. input address to the IOMMU). These addresses must be consistent with both the AMMU mapping as well as the linker command file. The ex02_messageq example from ipc defines these memory sections in the file examples/DRA7XX_linux_elf/ex02_messageq/shared/config.bld.

You can dump the IPU IOMMU page tables with the following commands:

Please see the corresponding DSP documentation for more details on interpreting the output.

Cortex M4 IPU Access to Peripherals

The default resource table creates the following mappings:

Example: Accessing UART5 from IPU

1. For this example, it’s assumed the pin-muxing was already setup in the bootloader. If that’s not the case, you would need to do that here.
2. The UART5 module needs to be enabled via the CM_L4PER_UART5_CLKCTRL register. This is located at physical address 0x4A009870. So from the M4 we would program this register at virtual address 0x6A009870. Writing a value of 2 to this register will enable the peripheral.
3. After completing the previous step, the UART5 registers will become accessible. Normally UART5 is accessible at physical base address 0x48066000. This would correspondingly be accessed from the IPU at 0x68066000.

The IPUs and DSPs auto-idle by default. This can prevent you from being able to connect to the device using JTAG or from accessing local memory via devmem2. There are some options sprinkled throughout sysfs that are needed in order to force these subsystems on, as is sometimes needed for development and debug purposes.

There are some hard-coded device names that originate in the device tree (dra7.dtsi) that are needed for these operations:

To map these System FS names to the associated remoteproc entry, you can run the following commands:

root@am57xx-evm:~# ls -l /sys/kernel/debug/remoteproc/
root@am57xx-evm:~# cat /sys/kernel/debug/remoteproc/remoteproc*/name

The results of the commands will be a one-to-one mapping. For example, 58820000.ipu corresponds with remoteproc0.

Similarly, to see the power state of each of the cores:

root@am57xx-evm:~# cat /sys/class/remoteproc/remoteproc*/state

The state can be suspended, running, offline, etc. You can only attach JTAG if the state is “running”. If it shows as “suspended” then you must force it to run. For example, let’s say DSP0 is “suspended”. You can run the following command to force it on:

root@am57xx-evm:~# echo on > /sys/bus/platform/devices/40800000.dsp/power/control

The same is true for any of the cores, but replace 40800000.dsp with the associated System FS name from the chart above.

Adding IPC to an existing TI RTOS application on the DSP

A common thing people want to do is take an existing DSP application and add IPC to it. This is common when migrating from a DSP only solution to a heterogeneous SoC with an Arm plus a DSP. This is the focus of this section.

In order to describe this process, we need an example test case to work with. For this purpose, we’ll be using the GPIO_LedBlink_evmAM572x_c66xExampleProject example that’s part of the PDK (installed as part of the Processor SDK RTOS). You can find it at c:/ti/pdk_am57xx_1_0_4/packages/MyExampleProjects/GPIO_LedBlink_evmAM572x_c66xExampleProject. This example uses SYS/BIOS and blinks the USER0 LED on the AM572x GP EVM, it’s labeled D4 on the EVM silkscreen just to the right of the blue reset button.

There were several steps taken to make this whole process work, each of which will be described in following sections

1. Build and run the out-of-box LED blink example on the EVM using Code Composer Studio (CCS)
2. Take the ex02_message example from the IPC software bundle and turn it into a CCS project. Build it and modify the Linux startup code to use this new image. This is just a sanity check step to make sure we can build the IPC examples in CCS and have them run at boot up on the EVM.
3. In CCS, make a clone of the out-of-box LED example and rename it to denote it’s the IPC version of the example. Then using the ex02_messageq example as a reference, add in the IPC pieces to the LED example. Build from CCS then add it to the Linux firmware folder.

Running LED Blink PDK Example from CCS

TODO - Fill this section in with instructions on how to run the LED blink example using JTAG and CCS after the board has booted Linux.

in a Linux environment, specifically, removed the GPIO interrupts and then added a Clock object to call the LED GPIO toggle function on a periodic bases.

Make CCS project out of ex02_messageq IPC example

TODO - fill this section in with instructions on how to make a CCS project out of the IPC example source files.

Add IPC to the LED Blink Example

The first step is to clone our out-of-box LED blink CCS project and rename it to denote it’s using IPC. The easiest way to do this is using CCS. Here are the steps...

• In the Edit perspective, go into your Project Explorer window and right click on your GPIO_LedBlink_evmAM572x+c66xExampleProject project and select copy from the pop-up menu. Maske sure the project is not is a closed state.
• Rick click in and empty area of the project explorer window and select past.
• A dialog box pops up, modify the name to denote it’s using IPC. A good name is GPIO_LedBlink_evmAM572x+c66xExampleProjec_with_ipc.

This is the project we’ll be working with from here on. The next thing we want to do is select the proper RTSC platform and other components. To do this, follow these steps.

• Right click on the GPIO_LedBlink_evmAM572x+c66xExampleProjec_with_ipc project and select Properties
• In the left hand pane, click on CCS General.
• On the right hand side, click on the RTSC tab
• For XDCtools version: select 3.32.0.06_core
• In the list of Products and Repositories, check the following...
  • IPC 3.43.2.04
  • SYS/BIOS 6.45.1.29
  • am57xx PDK 1.0.4
• For Target, select ti.targets.elf.C66
• For Platform, select ti.platforms.evmDRA7XX
• Once the platform is selected, edit its name buy hand and append :dsp1 to the end. After this it should be ti.platforms.evmDRA7XX:dsp1
• Go ahead and leave the Build-profile set to debug.
• Hit the OK button.

Now we want to copy configuration and source files from the ex02_messageq IPC example into our project. The IPC example is located at C:/ti/ipc_3_43_02_04/examples/DRA7XX_linux_elf/ex02_messageq. To copy files into your CCS project, you can simply select the files you want in Windows explorer then drag and drop them into your project in CCS.

Copy these files into your CCS project...

• C:/ti/ipc_3_43_02_04/examples/DRA7XX_linux_elf/ex02_messageq/shared/AppCommon.h
• C:/ti/ipc_3_43_02_04/examples/DRA7XX_linux_elf/ex02_messageq/shared/config.bld
• C:/ti/ipc_3_43_02_04/examples/DRA7XX_linux_elf/ex02_messageq/shared/ipc.cfg.xs

Now copy these files into your CCS project...

• C:/ti/ipc_3_43_02_04/examples/DRA7XX_linux_elf/ex02_messageq/dsp1/Dsp1.cfg
• C:/ti/ipc_3_43_02_04/examples/DRA7XX_linux_elf/ex02_messageq/dsp1/MainDsp1.c
• C:/ti/ipc_3_43_02_04/examples/DRA7XX_linux_elf/ex02_messageq/dsp1/Server.c
• C:/ti/ipc_3_43_02_04/examples/DRA7XX_linux_elf/ex02_messageq/dsp1/Server.h

Finally, you will likely want to use a custom resource table so copy these files into your CCS project...

• C:/ti/ipc_3_43_02_04/packages/ti/ipc/remoteproc/rsc_table_vayu_dsp.h
• C:/ti/ipc_3_43_02_04/packages/ti/ipc/remoteproc/rsc_types.h

The rsc_table_vayu_dsp.h file defines an initialized structure so let’s make a .c source file.

• In your CCS project, rename rsc_table_vayu_dsp.h to rsc_table_vayu_dsp.c

• Open up Dsp1.cfg using a text editor (don’t open it using the GUI). Right click on it and select Open With -> XDCscript Editor
• We want to copy the entire contents into the clipboard. Select all and copy.
• Now just like above, open the gpio_test_evmAM572x.cfg config file in the text editor. Go to the very bottom and paste in the contents from the Dsp1.cfg file. Basically we’ve appended the contents of Dsp1.cfg into gpio_test_evmAM572x.cfg.

We’ve now added in all the necessary configuration and source files into our project. Don’t expect it to build at this point, we have to make edits first. These edits are listed below.

• Edit gpio_test_evmAM572x.cfg

Add the following to the beginning of your configuration file

var Program = xdc.useModule('xdc.cfg.Program');

Comment out the Memory sections configuration as shown below

/* ================ Memory sections configuration ================ */
//Program.sectMap[".text"] = "EXT_RAM";
//Program.sectMap[".const"] = "EXT_RAM";
//Program.sectMap[".plt"] = "EXT_RAM";
/* Program.sectMap["BOARD_IO_DELAY_DATA"] = "OCMC_RAM1"; */
/* Program.sectMap["BOARD_IO_DELAY_CODE"] = "OCMC_RAM1"; */

Since we are no longer using a shared folder, make the following change

//var ipc_cfg = xdc.loadCapsule("../shared/ipc.cfg.xs");
var ipc_cfg = xdc.loadCapsule("../ipc.cfg.xs");

Comment out the following. We’ll be calling this function directly from main.

//BIOS.addUserStartupFunction('&IpcMgr_ipcStartup');

Increase the system stack size

//Program.stack = 0x1000;
Program.stack = 0x8000;

Comment out the entire TICK section

/* --------------------------- TICK --------------------------------------*/
// var Clock = xdc.useModule('ti.sysbios.knl.Clock');
// Clock.tickSource = Clock.TickSource_NULL;
// //Clock.tickSource = Clock.TickSource_USER;
// /* Configure BIOS clock source as GPTimer5 */
// //Clock.timerId = 0;
//
// var Timer = xdc.useModule('ti.sysbios.timers.dmtimer.Timer');
//
// /* Skip the Timer frequency verification check. Need to remove this later */
// Timer.checkFrequency = false;
//
// /* Match this to the SYS_CLK frequency sourcing the dmTimers.
//  * Not needed once the SYS/BIOS family settings is updated. */
// Timer.intFreq.hi = 0;
// Timer.intFreq.lo = 19200000;
//
// //var timerParams = new Timer.Params();
// //timerParams.period = Clock.tickPeriod;
// //timerParams.periodType = Timer.PeriodType_MICROSECS;
// /* Switch off Software Reset to make the below settings effective */
// //timerParams.tiocpCfg.softreset = 0x0;
// /* Smart-idle wake-up-capable mode */
// //timerParams.tiocpCfg.idlemode = 0x3;
// /* Wake-up generation for Overflow */
// //timerParams.twer.ovf_wup_ena = 0x1;
// //Timer.create(Clock.timerId, Clock.doTick, timerParams);
//
// var Idle = xdc.useModule('ti.sysbios.knl.Idle');
// var Deh = xdc.useModule('ti.deh.Deh');
//
// /* Must be placed before pwr mgmt */
// Idle.addFunc('&ti_deh_Deh_idleBegin');

Make configuration change to use custom resource table. Add to the end of the file.

/* Override the default resource table with my own */
var Resource = xdc.useModule('ti.ipc.remoteproc.Resource');
Resource.customTable = true;

• Edit main_led_blink.c

Add the following external declarations

extern Int ipc_main();
extern Void IpcMgr_ipcStartup(Void);

In main(), add a call to ipc_main() and IpcMgr_ipcStartup() just before BIOS_start()

ipc_main();

if (callIpcStartup) {
    IpcMgr_ipcStartup();
}

/* Start BIOS */
BIOS_start();
return (0);

Comment out the line that calls Board_init(boardCfg). This call is in the original example because it assumes TI-RTOS is running on the Arm but in our case here, we are running Linux and this call is destructive so we comment it out.

#if defined(EVM_K2E) || defined(EVM_C6678)
    boardCfg = BOARD_INIT_MODULE_CLOCK |
    BOARD_INIT_UART_STDIO;
#else
    boardCfg = BOARD_INIT_PINMUX_CONFIG |
    BOARD_INIT_MODULE_CLOCK |
    BOARD_INIT_UART_STDIO;
#endif
    //Board_init(boardCfg);

• Edit MainDsp1.c

The app now has it’s own main(), so rename this one and get rid of args

//Int main(Int argc, Char* argv[])
Int ipc_main()
{

No longer using args so comment these lines

//taskParams.arg0 = (UArg)argc;
//taskParams.arg1 = (UArg)argv;

BIOS_start() is done in the app main() so comment it out here

/* start scheduler, this never returns */
//BIOS_start();

Comment this out

//Log_print0(Diags_EXIT, "<-- main:");

• Edit rsc_table_vayu_dsp.c

Set this #define before it’s used to select PHYS_MEM_IPC_VRING value

#define VAYU_DSP_1

Add this extern declaration prior to the symbol being used

extern char ti_trace_SysMin_Module_State_0_outbuf__A;

• Edit Server.c

No longer have shared folder so change include path

/* local header files */
//#include "../shared/AppCommon.h"
#include "../AppCommon.h"

Download the Full CCS Project

GPIO_LedBlink_evmAM572x_c66xExampleProject_with_ipc.zip

Adding IPC to an existing TI RTOS application on the IPU

A common thing people want to do is take an existing IPU application that may be controlling serial or control interfaces and add IPC to it so that the firmware can be loaded from the ARM. This is common when migrating from a IPU only solution to a heterogeneous SoC with an MPUSS (ARM) and IPUSS. This is the focus of this section.

In order to describe this process, we need an example TI RTOS test case to work with. For this purpose, we’ll be using the UART_BasicExample_evmAM572x_m4ExampleProject example that’s part of the PDK (installed as part of the Processor SDK RTOS). This example uses TI RTOS and does serial IO using UART3 port on the AM572x GP EVM, it’s labeled Serial Debug on the EVM silkscreen.

There were several steps taken to make this whole process work, each of which will be described in following sections

1. Build and run the out-of-box UART M4 example on the EVM using Code Composer Studio (CCS)
2. Build and run the ex02_messageQ example from the IPC software bundle and turn it into a CCS project. Build it and modify the Linux startup code to use this new image. This is just a sanity check step to make sure we can build the IPC examples in CCS and have them run at boot up on the EVM.
3. In CCS, make a clone of the out-of-box UART M4 example and rename it to denote it’s the IPC version of the example. Then using the ex02_messageq example as a reference, add in the IPC pieces to the UART example code. Build from CCS then add it to the Linux firmware folder.

Running UART Read/Write PDK Example from CCS

Developers are required to run pdkProjectCreate script to generate this example as described in the Processor SDK RTOS wiki article.

For the UART M4 example run the script with the following arguments:

pdkProjectCreate.bat AM572x evmAM572x little uart m4

After you run the script, you can find the UART M4 example project at <SDK_INSTALL_PATH>/pdk_am57xx_1_0_4/packages/MyExampleProjects/UART_BasicExample_evmAM572x_m4ExampleProject.

Import the project in CCS and build the example. You can now connect to the EVM using an emulator and CCS using the instructions provided here: https://processors.wiki.ti.com/index.php/AM572x_GP_EVM_Hardware_Setup

Connect to the ARM core and make sure GEL runs multicore initialization and brings the IPUSS out of reset. Connect to IPU2 core0 and load and run the M4 UART example. When you run the code you should see the following log on the serial IO console:

uart driver and utils example test cases :
Enter 16 characters or press Esc
1234567890123456  <- user input
Data received is
1234567890123456  <- loopback from user input
uart driver and utils example test cases :
Enter 16 characters or press Esc

Build and Run ex02_messageq IPC example

Follow instructions described in Article Run IPC Linux Examples

Update Linux Kernel device tree to remove UART that will be controlled by M4

Linux kernel enables all SOC HW modules which are required for its configuration. Appropriate drivers configure required clocks and initialize HW registers. For all unused IPs clocks are not configured.

The uart3 node is disabled in kernel using device tree. Also this restricts kernel to put those IPs to sleep mode.

&uart3 {
    status = "disabled";
    ti,no-idle;
};

Add IPC to the UART Example

The first step is to clone our out-of-box UART example CCS project and rename it to denote it’s using IPC. The easiest way to do this is using CCS. Here are the steps...

• In the Edit perspective, go into your Project Explorer window and right click on your UART_BasicExample_evmAM572x_m4ExampleProject project and select copy from the pop-up menu. Maske sure the project is not is a closed state.
• Rick click in and empty area of the project explorer window and select past.
• A dialog box pops up, modify the name to denote it’s using IPC. A good name is UART_BasicExample_evmAM572x_m4ExampleProject_with_ipc.

This is the project we’ll be working with from here on. The next thing we want to do is select the proper RTSC platform and other components. To do this, follow these steps.

• Right click on the UART_BasicExample_evmAM572x_m4ExampleProject_with_ipc project and select Properties
• In the left hand pane, click on CCS General.
• On the right hand side, click on the RTSC tab
• For XDCtools version: select 3.xx.x.xx_core
• In the list of Products and Repositories, check the following...
  • IPC 3.xx.x.xx
  • SYS/BIOS 6.4x.x.xx
  • am57xx PDK x.x.x
• For Target, select ti.targets.arm.elf.M4
• For Platform, select ti.platforms.evmDRA7XX
• Once the platform is selected, edit its name buy hand and append :ipu2 to the end. After this it should be ti.platforms.evmDRA7XX:ipu2
• Go ahead and leave the Build-profile set to debug.
• Hit the OK button.

Now we want to copy configuration and source files from the ex02_messageq IPC example into our project. The IPC example is located at C:/ti/ipc_3_xx_xx_xx/examples/DRA7XX_linux_elf/ex02_messageq. To copy files into your CCS project, you can simply select the files you want in Windows explorer then drag and drop them into your project in CCS.

Copy these files into your CCS project...

• C:/ti/ipc_3_xx_xx_xx/examples/DRA7XX_linux_elf/ex02_messageq/shared/AppCommon.h
• C:/ti/ipc_3_xx_xx_xx/examples/DRA7XX_linux_elf/ex02_messageq/shared/config.bld
• C:/ti/ipc_3_xx_xx_xx/examples/DRA7XX_linux_elf/ex02_messageq/shared/ipc.cfg.xs

Now copy these files into your CCS project...

• C:/ti/ipc_3_xx_xx_xx/examples/DRA7XX_linux_elf/ex02_messageq/ipu2/Ipu2.cfg
• C:/ti/ipc_3_xx_xx_xx/examples/DRA7XX_linux_elf/ex02_messageq/ipu2/MainIpu2.c
• C:/ti/ipc_3_xx_xx_xx/examples/DRA7XX_linux_elf/ex02_messageq/ipu2/Server.c
• C:/ti/ipc_3_xx_xx_xx/examples/DRA7XX_linux_elf/ex02_messageq/ipu2/Server.h

Finally, you will likely want to use a custom resource table so copy these files into your CCS project...

• C:/ti/ipc_3_xx_xx_xx/packages/ti/ipc/remoteproc/rsc_table_vayu_ipu.h
• C:/ti/ipc_3_xx_xx_xx/packages/ti/ipc/remoteproc/rsc_types.h

The rsc_table_vayu_dsp.h file defines an initialized structure so let’s make a .c source file.

• In your CCS project, rename rsc_table_vayu_ipu.h to rsc_table_vayu_ipu.c

Now we want to merge the IPC example configuration file with the LED blink example configuration file. Follow these steps...

• Open up Ipu2.cfg using a text editor (don’t open it using the GUI). Right click on it and select Open With -> XDCscript Editor
• We want to copy the entire contents into the clipboard. Select all and copy.
• Now just like above, open the uart_m4_evmAM572x.cfg config file in the text editor. Go to the very bottom and paste in the contents from the Ipu2.cfg file. Basically we’ve appended the contents of Ipu2.cfg into uart_m4_evmAM572x.cfg.

We’ve now added in all the necessary configuration and source files into our project. Don’t expect it to build at this point, we have to make edits first. These edits are listed below.

• Edit uart_m4_evmAM572x.cfg

Add the following to the beginning(at the top) of your configuration file

var Program = xdc.useModule('xdc.cfg.Program');

Since we are no longer using a shared folder, make the following change

//var ipc_cfg = xdc.loadCapsule("../shared/ipc.cfg.xs");
var ipc_cfg = xdc.loadCapsule("../ipc.cfg.xs");

Comment out the following. We’ll be calling this function directly from main.

//BIOS.addUserStartupFunction('&IpcMgr_ipcStartup');

Increase the system stack size

//Program.stack = 0x1000;
Program.stack = 0x8000;

Comment out the entire TICK section

/* --------------------------- TICK --------------------------------------*/
// var Clock = xdc.useModule('ti.sysbios.knl.Clock');
// Clock.tickSource = Clock.TickSource_NULL;
// //Clock.tickSource = Clock.TickSource_USER;
// /* Configure BIOS clock source as GPTimer5 */
// //Clock.timerId = 0;
//
// var Timer = xdc.useModule('ti.sysbios.timers.dmtimer.Timer');
//
// /* Skip the Timer frequency verification check. Need to remove this later */
// Timer.checkFrequency = false;
//
// /* Match this to the SYS_CLK frequency sourcing the dmTimers.
//  * Not needed once the SYS/BIOS family settings is updated. */
// Timer.intFreq.hi = 0;
// Timer.intFreq.lo = 19200000;
//
// //var timerParams = new Timer.Params();
// //timerParams.period = Clock.tickPeriod;
// //timerParams.periodType = Timer.PeriodType_MICROSECS;
// /* Switch off Software Reset to make the below settings effective */
// //timerParams.tiocpCfg.softreset = 0x0;
// /* Smart-idle wake-up-capable mode */
// //timerParams.tiocpCfg.idlemode = 0x3;
// /* Wake-up generation for Overflow */
// //timerParams.twer.ovf_wup_ena = 0x1;
// //Timer.create(Clock.timerId, Clock.doTick, timerParams);
//
// var Idle = xdc.useModule('ti.sysbios.knl.Idle');
// var Deh = xdc.useModule('ti.deh.Deh');
//
// /* Must be placed before pwr mgmt */
// Idle.addFunc('&ti_deh_Deh_idleBegin');

Make configuration change to use custom resource table. Add to the end of the file.

/* Override the default resource table with my own */
var Resource = xdc.useModule('ti.ipc.remoteproc.Resource');
Resource.customTable = true;

• Edit main_uart_example.c

Add the following external declarations

extern Int ipc_main();
extern Void IpcMgr_ipcStartup(Void);

In main(), add a call to ipc_main() and IpcMgr_ipcStartup() just before BIOS_start()

ipc_main();
if (callIpcStartup) {
   IpcMgr_ipcStartup();
 }
 /* Start BIOS */
 BIOS_start();
 return (0);

Comment out the line that calls Board_init(boardCfg). This call is in the original example because it assumes TI-RTOS is running on the Arm but in our case here, we are running Linux and this call is destructive so we comment it out. The board init call does all pinmux configuration, module clock and UART peripheral initialization.

In order to run the UART Example on M4, you need to disable the UART in the Linux DTB file and interact with the Linux kernel using Telnet (This will be described later in the article). Since Linux will be running uboot performs the pinmux configuration but clock and UART Stdio setup needs to be performed by the M4.

Original code

#if defined(EVM_K2E) || defined(EVM_C6678)
    boardCfg = BOARD_INIT_MODULE_CLOCK | BOARD_INIT_UART_STDIO;
#else
    boardCfg = BOARD_INIT_PINMUX_CONFIG | BOARD_INIT_MODULE_CLOCK | BOARD_INIT_UART_STDIO;
#endif
    Board_init(boardCfg);

Modified Code :

boardCfg = BOARD_INIT_UART_STDIO;
Board_init(boardCfg);

We are not done yet as we still need to configure turn the clock control on for the UART without impacting the other clocks. We can do that by adding the following code before Board_init API call:

CSL_l4per_cm_core_componentRegs *l4PerCmReg =
    (CSL_l4per_cm_core_componentRegs *)CSL_MPU_L4PER_CM_CORE_REGS;
CSL_FINST(l4PerCmReg->CM_L4PER_UART3_CLKCTRL_REG,
    L4PER_CM_CORE_COMPONENT_CM_L4PER_UART3_CLKCTRL_REG_MODULEMODE, ENABLE);
while(CSL_L4PER_CM_CORE_COMPONENT_CM_L4PER_UART3_CLKCTRL_REG_IDLEST_FUNC !=
   CSL_FEXT(l4PerCmReg->CM_L4PER_UART3_CLKCTRL_REG,
    L4PER_CM_CORE_COMPONENT_CM_L4PER_UART3_CLKCTRL_REG_IDLEST));

• Edit MainIpu2.c

The app now has it’s own main(), so rename this one and get rid of args

//Int main(Int argc, Char* argv[])
Int ipc_main()
{

No longer using args so comment these lines

//taskParams.arg0 = (UArg)argc;
//taskParams.arg1 = (UArg)argv;

BIOS_start() is done in the app main() so comment it out here

/* start scheduler, this never returns */
//BIOS_start();

Comment this out

//Log_print0(Diags_EXIT, "<-- main:");

• Edit rsc_table_vayu_ipu.c

Set this #define before it’s used to select PHYS_MEM_IPC_VRING value

#define VAYU_IPU_2

Add this extern declaration prior to the symbol being used

extern char ti_trace_SysMin_Module_State_0_outbuf__A;

• Edit Server.c

No longer have shared folder so change include path

/* local header files */
//#include "../shared/AppCommon.h"
#include "../AppCommon.h"

Handling AMMU (L1 Unicache MMU) and L2 MMU

There are two MMUs inside each of the IPU1, and IPU2 subsystems. The L1 MMU is referred to as IPU_UNICACHE_MMU or AMMU and L2 MMU. The description of how this is configured in IPC-remoteproc has been described in section Changing_Cortex_M4_IPU_Memory_Map. IPC handling of L1 and L2 MMU is different from how the PDK driver examples setup the memory access using these MMUs which the users need to manage when integrating the components. This difference is highlighted below:

• PDK examples use addresses (0x4X000000) to peripheral registers and use following MMU setting
  • L2 MMU uses default 1:1 Mapping
  • AMMU configuration translates physical 0x4X000000 access to logical 0x4X000000
• IPC+ Remote Proc ARM+M4 requires IPU to use logical address (0x6X000000) and uses following MMU setting
  • L2 MMU is configured such that MMU translates 0x6X000000 access to addresss 0x4X000000
  • AMMU is configured for 1:1 mapping 0x6X000000 and 0x6X000000

Therefore after integrating IPC with PDK drivers, it is recommended that the alias addresses are used to access peripherals and PRCM registers. This requires changes to the addresses used by PDK drivers and in application code.

The following changes were then made to the IPU application source code:

Add UART_soc.c file to the project and modify the base addresses for all IPU UART register instance in the UART_HwAttrs to use alias addresses:

#ifdef _TMS320C6X
    CSL_DSP_UART3_REGS,
    OSAL_REGINT_INTVEC_EVENT_COMBINER,
#elif defined(__ARM_ARCH_7A__)
    CSL_MPU_UART3_REGS,
    106,
#else
    (CSL_IPU_UART3_REGS + 0x20000000),    //Base Addr = 0x48000000 + 0x20000000 = 0x68000000
    45,
#endif

Adding custom SOC configuration also means that you should use the generic UART driver instead of driver with built in SOC setup. To do this comment the following line in .cfg:

var Uart              = xdc.loadPackage('ti.drv.uart');
//Uart.Settings.socType = socType;

There is also an instance in the application code where we added pointer to PRCM registers that need to be changed as follows.

 CSL_l4per_cm_core_componentRegs *l4PerCmReg =
(CSL_l4per_cm_core_componentRegs *) 0x6a009700; //CSL_MPU_L4PER_CM_CORE_REGS;

Now, you are ready to build the firmware. After the .out is built, change the extension to .xem4 and copy it over to the location in the filesystem that is used to load M4 firmware.

10.8.2. Customizing Memory map for creating Multicore Applications on AM57xx using IPC¶

https://www.ti.com/lit/an/sprac60/sprac60.pdf

10.8.3. IPC Debugging Tools and Techniques on AM57xx¶

The sections relevant to AM57xx have been pulled from the Debugging Tools and Techniques With IPC3.x Application Note and placed here.

During development of software, it is common to encounter issues that must be debugged to provide a robust software offering. When developing software that uses the IPC3.x product for inter-processor communication, there are tools and techniques available to aid in the debugging process. These tools and techniques help to more quickly understand and debug the issue. This document addresses all three HLOS’s supported by IPC3.x: Android™ platform, Linux®, and QNX®. Where applicable, differences between the OS’s are noted. This document aims to provide tools, techniques, and resources for debugging issues encountered when using the IPC3.x to communicate with remote core software.

There are several tools that can be leveraged for debugging the IPC, from simple tracing to using Code Composer Studio™ (CCS) to attach to the remote cores. Each provides different advantages in the debugging process.

When an issue occurs, checking the traces is often the first thing done. The traces can give quick insight into what may be happening. In normal, non-error cases, you might see little to no traces from the IPC. But when there is an error, there often is an error trace that can be used to shed light on the issue. An error trace often gives an error code and a module or function name that can be used to identify where the error was thrown.

Another useful place to look for debug info is in the debugfs. Information for each remote processor can be found there, as well as remote core traces, state information, and more.

Connecting over JTAG using Code Composer Studio provides the ability to see exactly what is happening on the remote core, providing access to a wealth of information including viewing memory, registers, and stepping through the code.

The first place to check when an issue occurs is the traces. Often an error code or a trace regarding an error gives some clue. Both the remote core traces and the HLOS-side traces can be checked.

By default, the IPC only prints error traces. To enable additional tracing, use the IPC_DEBUG environment variable at runtime. This feature is only supported on Linux and is available starting in IPC 3.22.00.05. Table 1 lists the two levels of tracing supported.

Table 1. IPC_DEBUG Trace Levels

When using QNX, additional traces are enabled by setting environment variables. There are separate environment variables for enabling traces in the resource manager and the user libraries.

Resource Manager Traces

Enable additional traces in the slog by setting the environment variable IPC_DEBUG_SLOG_LEVEL at runtime. By default, only errors and warnings are printed. The IPC_DEBUG_SLOG_LEVEL can be set before launching IPC to enable more traces. Setting the level to 7 enables all IPC traces. The default level is 2.

export IPC_DEBUG_SLOG_LEVEL=7

These traces are printed to the slog, and can be viewed by using the sloginfo command. All IPC traces use 42 as identification in the slog, and you can filter the slog to view only these traces:

sloginfo –m42

User Library Traces

User library traces can be enabled by using the variable IPC_DEBUG when launching the application. Valid levels are 1 to 3, with 3 being the most verbose. For example:

IPC_DEBUG=<level> app_host

The remote core traces can be checked by using debugfs. Run the following command, replacing the “X” with the core-id for the remote core to be checked.

cat /sys/kernel/debug/remoteproc/remoteprocX/trace0

Check the following when checking the traces after an error recovery has occurred:

cat /sys/kernel/debug/remoteproc/remoteprocX/trace0_last

This provides the last traces that happened before error recovery was triggered. For more information about debugging remote core faults and exceptions, see `Debugging MMU Faults and Exceptions`_.

The core-id, “X”, starts at 0 and increments to include all of the remote cores supported by the remoteproc module in the dts file. Because the number of remoteprocs supported can vary depending on the dts configuration, it is not ensured that a certain remote core will always have a certain core-id if the remoteprocs supported in the dts file changes.

The core associated with a particular core-id can be found by checking the name of the remoteproc (see `Linux and Android - Remoteproc`_). Table 2 associates the remoteproc name with the common name of the remote processor.

cat /sys/kernel/debug/remoteproc/remoteprocX/name

Table 2. Remoteproc Names for AM57xx

The remote core traces can be checked by using sysfs. Run the following command, replacing <core name> with the core name for the remote core to check. Valid core names for AM57xx are IPU1, IPU2, DSP1, and DSP2.

cat /dev/ipc-trace/<core name>

When checking the traces after error recovery has happened, check the logfile specified at IPC startup, if one was specified. When starting IPC, specify a logfile using the “-c” option. When an error recovery happens, the last traces are dumped to this log file. For more information about debugging remote core faults and exceptions, see `Debugging MMU Faults and Exceptions`_.

In some cases, you may want to add traces to get more information about the issue. If the issue is reliably reproducible, one technique is to add additional traces to get more information. If the issue is timing-related, this technique may not be helpful, as it may mask the issue

SYS-BIOS

You can add traces in the SYS-BIOS IPC code that come to the trace buffer by using the System_printf() API. After adding traces to the SYS-BIOS IPC and rebuilding the IPC, you must rebuild the remote core image. The traces come to the remote core trace buffer and can be viewed by following the instructions in `Linux and Android - Remote Core Traces`_.

Linux

Additionally, traces can be added in the Linux code. The modules of interest when adding traces are the remoteproc, iommu, and rpmsg modules in the kernel, and the MessageQ, MMRPC, and LAD modules in the user space.

In the kernel are these modules in the following paths:

• drivers/remoteproc/
• drivers/iommu/
• drivers/rpmsg/

Most of the user space code can be found in the IPC package, in the linux folder. The MMRPC code is found in the packages/ti/ipc/mm/ folder.

Useful information about the status of the remote cores can be found in debugfs.

Information about each remote core can be found in the following, where the “X” can be replaced with the remote core id.

cat /sys/kernel/debug/remoteproc/remoteprocX/<entry>

Table 3 lists what can be found for each core.

Table 3. Remoteproc Debugfs Entries

Information about the IOMMU can also be found in debugfs. It can be found in the following path, where “XXXXXXXX” is replaced by the register address for the remote core MMU registers.

cat /sys/kernel/debug/omap_iommu/XXXXXXXX.mmu/<entry>

Table 4 gives the corresponding core name for each MMU for AM57xx, and the register address in the TRM.

Table 4. IOMMU Entry Names

Some of this information is inaccessible from a suspended state. Table 5 lists what can be found for each core.

Table 5. IOMMU Debugfs Entries

Find out the current state of the remote core by issuing the following command:

cat /dev/ipc-state/<core_name>

The “core_name” is the name of the remote core. Valid names for AM57xx are IPU1, IPU2, DSP1, and DSP2. The current state will show as “running” or “reset”.

A useful tool for debugging issues is Code Composer Studio. CCS allows easy connection to the remote core in order to see the state of the remote core.

The remote core image must be built with debug symbols to see information such as the call stack and variables. Once attached, load the symbols. The symbols are built into the executable itself. When loading symbols, point to the same executable that is loaded on the target (or the unstripped version locally, if it is stripped to save space when loading to the target.)

You may want to disable auto-suspend of the remote cores (provided that is not what is being debugged). When the core is suspended, you will not be able to connect to the remote core using CCS. Auto-suspend can be disabled by setting the power control to “on” for the remote core.

echo on > /sys/bus/platform/devices/<device>/power/control

The remote core device name for each remote core can be found in Table 2.

You may decide to disable the watchdog timers when debugging and using CCS. Otherwise, while connected to the target, the watchdog may expire, triggering an abort sequence. Disable the watchdog timers for a remote core by removing their definitions from the dts file. For example, to disable the watchdog timers for IPU1, change the dts file as below:

&ipu1 {
    status = "okay";

    memory-region = <&ipu1_cma_pool>;

    mboxes = <&mailbox5 &mbox_ipu1_legacy>;

    timers = <&timer11>;

   - watchdog-timers = <&timer7>, <&timer8>;

   + /*watchdog-timers = <&timer7>, <&timer8>;*/

When using QNX, you can disable the watchdog from within the remote core image itself. If using Linux or Android, this step is not required; simply follow the instructions in `Linux and Android – Disabling Watchdog`_.

To disable the usage of the watchdog from the remote core without completely disabling the device exception module (DEH), comment out the calls to Watchdog_init in the SYS/BIOS IPC code. These calls can be found in packages/ti/deh/Deh.c, packages/ti/deh/DehDsp.c, and packages/ti/ipc/ipcmgr/IpcMgr.c.

packages/ti/deh/Deh.c:

/*
* ======== Deh_Module_startup ========
*/
Int Deh_Module_startup(Int phase)
{
if (AMMU_Module_startupDone() == TRUE) {
- Watchdog_init(ti_sysbios_family_arm_m3_Hwi_excHandlerAsm__I);
+ //Watchdog_init(ti_sysbios_family_arm_m3_Hwi_excHandlerAsm__I);
return Startup_DONE;
}
return Startup_NOTDONE;
}

packages/ti/deh/DehDsp.c:

Int Deh_Module_startup(Int phase)
{
#if defined(HAS_AMMU)
if (AMMU_Module_startupDone() == TRUE) {
- Watchdog_init((Void (*)(Void))ti_sysbios_family_c64p_Exception_handler);
+ //Watchdog_init((Void (*)(Void))ti_sysbios_family_c64p_Exception_handler);
return Startup_DONE;
}
return Startup_NOTDONE;
#else
- Watchdog_init((Void (*)(Void))ti_sysbios_family_c64p_Exception_handler);
+ //Watchdog_init((Void (*)(Void))ti_sysbios_family_c64p_Exception_handler);
return Startup_DONE;
#endif

packages/ti/ipc/ipcmgr/IpcMgr.c:

Void IpcMgr_rpmsgStartup(Void)
{
Assert_isTrue(MultiProc_self() != MultiProc_getId("HOST"), NULL);
RPMessage_init(MultiProc_getId("HOST"));
-#ifdef IpcMgr_USEDEH
+#if 0
/*
* When using DEH, initialize the Watchdog timers if not already done
* (i.e. late-attach)
*/
#ifdef IpcMgr_DSP
Watchdog_init((Void (*)(Void))ti_sysbios_family_c64p_Exception_handler);
#elif IpcMgr_IPU
Watchdog_init(ti_sysbios_family_arm_m3_Hwi_excHandlerAsm__I);
#endif
#endif
}
[...]
Void IpcMgr_ipcStartup(Void)
{
UInt procId = MultiProc_getId("HOST");
Int status;
/* TransportRpmsgSetup will busy wait until host kicks ready to recv: */
status = TransportRpmsgSetup_attach(procId, 0);
Assert_isTrue(status >= 0, NULL);
/* Sets up to communicate with host's NameServer: */
status = NameServerRemoteRpmsg_attach(procId, 0);
Assert_isTrue(status >= 0, NULL);
-#ifdef IpcMgr_USEDEH
+#if 0
/*
* When using DEH, initialize the Watchdog timers if not already done
* (i.e. late-attach)
*/
#ifdef IpcMgr_DSP
Watchdog_init((Void (*)(Void))ti_sysbios_family_c64p_Exception_handler);
#elif IpcMgr_IPU
Watchdog_init(ti_sysbios_family_arm_m3_Hwi_excHandlerAsm__I);
#endif
#endif
}

Following this, rebuild the IPC and the remote core image to have an image with DEH, but without watchdog enabled.

In certain cases, you may want to attach to the remote core before the issue has occurred. If the issue is reliably reproducible and always occurs at the same location, then adding a breakpoint close to where the issue happens could be a good way to get a better picture of what is happening.

One instance where it may be difficult is if the issue is happening during boot-up of the remote core. In this case, it may be necessary to add a while loop in the main function, to attach before the issue occurs. Add a loop similar to this:

{
volatile int foo = 1;
while (foo);
}

Then, after attaching, load the symbols, add the breakpoints, change “foo” to 0, and continue running.

You can also attach to the core after the issue, load the symbols, and see the state and view memory. You can view the Exception module’s exception CallStack ROV view and the task module’s per task CallStack ROV view. For more information about the runtime object viewer (ROV) in the RTSC documentation online, see Runtime Object Viewer.

Once attached and with symbols loaded, the state of the processor can be inspected. You can see the program counter, memory windows, registers, call stack, and the ROV, among other things.

Errors commonly manifest as MMU faults, exceptions, and watchdog errors (if using a version of IPC with watchdog available and enabled).

To debug an error, it may be necessary to turn of error recovery. Error recovery can be disabled by giving the following command:

echo disabled > /sys/kernel/debug/remoteproc/remoteprocX/recovery

See `Linux and Android - Remoteproc`_ for more information.

To disable error recovery on QNX using IPC version 3.22 and above, give the -d option when launching the ipc binary. For example:

ipc –d IPU2 dra7x-ipu2-fw.xem4

If any of these three errors are encountered, you will get a crash dump from the remote core which is visible in the remote core traces. If error recovery is disabled, the dump can be found in trace0 (when using Linux/Android) or in /dev/ipc-trace/<core_name> (when using QNX); otherwise, the trace is found in trace0_last (when using Linux/Android) and in the logfile (when using QNX).

An example of the crash dump will look like this:

[0] [ 91.045] Exception occurred at (PC) = 0000c976

[0] [ 91.045] CPU context: thread

[0] [ 91.045] BIOS Task name: {empty-instance-name} handle: 0x80060090.

[0] [ 91.045] BIOS Task stack base: 0x800600e0.

[0] [ 91.045] BIOS Task stack size: 0x800.

[0] [ 91.045] [t=0x18f6df13] ti.sysbios.family.arm.m3.Hwi: ERROR: line 1078: E_hardFault: FORCED

[0] [ 91.045] ti.sysbios.family.arm.m3.Hwi: line 1078: E_hardFault: FORCED

[0] [ 91.045] [t=0x18f9a0cb] ti.sysbios.family.arm.m3.Hwi: ERROR: line 1155: E_busFault: PRECISERR: Immediate Bus Fault, exact addr known, address: 96000000

[0] [ 91.045] ti.sysbios.family.arm.m3.Hwi: line 1155: E_busFault: PRECISERR: Immediate Bus

Fault, exact addr known, address: 96000000

[0] [ 91.045] R0 = 0x96000000 R8 = 0xffffffff

[0] [ 91.045] R1 = 0x00000000 R9 = 0xffffffff

[0] [ 91.045] R2 = 0x00000000 R10 = 0xffffffff

[0] [ 91.045] R3 = 0x80060814 R11 = 0xffffffff

[0] [ 91.045] R4 = 0x00013098 R12 = 0x8006074c

[0] [ 91.045] R5 = 0x0000000a SP(R13) = 0x80060820

[0] [ 91.045] R6 = 0xffffffff LR(R14) = 0x0000c973

[0] [ 91.045] R7 = 0xffffffff PC(R15) = 0x0000c976

[0] [ 91.045] PSR = 0x61000000

[0] [ 91.045] ICSR = 0x00438803

[0] [ 91.045] MMFSR = 0x00

[0] [ 91.045] BFSR = 0x82

[0] [ 91.045] UFSR = 0x0000

[0] [ 91.045] HFSR = 0x40000000

[0] [ 91.045] DFSR = 0x00000000

[0] [ 91.045] MMAR = 0x96000000

[0] [ 91.045] BFAR = 0x96000000

[0] [ 91.045] AFSR = 0x00000000

[0] [ 91.045] Stack trace

[0] [ 91.045] 00 [op faaaf00e] 00006abd (ret from call to 00015010)

[0] [ 91.045] 01 [op ff49f005] 00006ac3 (ret from call to 0000c954)

[0] [ 91.045] -- [op 98009000] 000154c9

[0] [ 91.045] -- [op 00000000] 000a0001

[0] [ 91.045] -- [op 80084a64] 0000fec9

[0] [ 91.045] -- [op 0001a75c] 000068b9

[0] [ 91.045] -- [op 80084a64] 0000fec9

[0] [ 91.045] -- [op bd0ef919] 00015b91

[0] [ 91.045] Stack dump base 800600e0 size 2048 sp 80060820:

[0] [ 91.045] 80060820: 00000001 00006abd 96000000 00000000 ffffffff 00006ac3 0000000a 00006bf4

[0] [ 91.045] 80060840: 00000000 00000000 80041800 80060ab0 00000080 56414c53 50495f45 be003155

[0] [ 91.045] 80060860: bebebebe bebebebe bebebebe bebebebe bebebebe bebebebe bebebebe bebebebe

[0] [ 91.045] 80060880: bebebebe bebebebe bebebebe bebebebe bebebebe 00000000 00000000 00000001

[0] [ 91.045] 800608a0: 00000001 000154c9 0001309a 0000000a 00000000 80041820 00000001 ffffffff

[0] [ 91.045] 800608c0: ffffffff 0000fec9 00000000 00000000 000068b9 0000fec9 00015b91 bebebebe

[0] [ 91.045] Terminating execution...

Some useful information that can be found in the dump is the fault address, PC address, register contents, and call stack.

When an error occurs, you gets a crash dump from the remote core that looks similar to the one in `Crash Dump`_.

The particular dump example above is from a MMU read fault. This dump provides important information in helping to understand what has happened. Some of the useful parts are broken down in the following section.

Timestamp

All traces (not just exception dumps) provide a timestamp for each trace. The time starts from the booting of the remote core.

[0] [ 91.045] Exception occurred at (PC) = 0000c976

[0] [ 91.045] CPU context: thread

[0] [ 91.045] BIOS Task name: {empty-instance-name} handle: 0x80060090.

The timestamp information can be useful even in non-crash situations, indicating the amount of time taken between two events. You can add traces at each event and then see when the events run.

For example, to check that a certain event is happening every second, put a trace at that event, then check the timestamps to see that it is happening as expected.

PC Address

The PC address where the exception occurred is also provided. This can be used, in conjunction with the map file or CCS, to identify the line of code where the exception happened.

[0] [ 91.045] Exception occurred at (PC) = 0000c976

[0] [ 91.045] CPU context: thread

[0] [ 91.045] BIOS Task name: {empty-instance-name} handle: 0x80060090.

Task Information

The information about the task that was executing when the exception occurred is also provided.

[0] [ 91.045] Exception occurred at (PC) = 0000c976

[0] [ 91.045] CPU context: thread

[0] [ 91.045] BIOS Task name: {empty-instance-name} handle: 0x80060090.

[0] [ 91.045] BIOS Task stack base: 0x800600e0.

[0] [ 91.045] BIOS Task stack size: 0x800.

Fault Information

The information about the fault is also provided. This can look different depending on the type of exception that occurred, but often provides a fault address to identify the source of the fault.

[0] [ 91.045] Exception occurred at (PC) = 0000c976

[0] [ 91.045] CPU context: thread

[0] [ 91.045] BIOS Task name: {empty-instance-name} handle: 0x80060090.

[0] [ 91.045] BIOS Task stack base: 0x800600e0.

[0] [ 91.045] BIOS Task stack size: 0x800.

[0] [ 91.045] [t=0x18f6df13] ti.sysbios.family.arm.m3.Hwi: ERROR: line 1078: E_hardFault: FORCED

[0] [ 91.045] ti.sysbios.family.arm.m3.Hwi: line 1078: E_hardFault: FORCED

[0] [ 91.045] [t=0x18f9a0cb] ti.sysbios.family.arm.m3.Hwi: ERROR: line 1155: E_busFault: PRECISERR: Immediate Bus Fault, exact addr known, address: 96000000

[0] [ 91.045] ti.sysbios.family.arm.m3.Hwi: line 1155: E_busFault: PRECISERR: Immediate Bus Fault, exact addr known, address: 96000000

Registers

A dump of the register contents at the time of the exception is also provided.

Stack Trace

The stack trace is also provided (see Figure 6). This can be used in conjunction with the source code and the map file or CCS to get more information about what was executing at the time of the crash.

MMU faults occur when an address that is not mapped to the remote core MMU is accessed. This can be due to a read, write, or an attempt to execute the address. When an MMU fault occurs, a crash dump from the remote core occurs that looks similar to the example provided in `Crash Dump`_.

Some debugging techniques, as well as common times when an MMU fault occurs, are given as examples in the following sections.

Using CCS to Halt the Code When the Fault Happens

If the fault always happens at the same address, pre-map the location and then set up CCS with a breakpoint for that address. In this way, you can view the state of the remote core when the fault happens and see the call stack. From there, put a breakpoint at the surrounding code and step through to see where the fault happens.

Pre-mapping the address can be done either through the remote core resource table, or through CCS. With CCS, you can connect to the debug DAP and then bring up a memory window to inspect the MMU registers. Directly program the MMU from here to map some unused memory to the fault address location.

For example:

• MMU CAM: 0x9600000E (Change the most significant 20 bits here to match the fault address. For example, it would be 96000 if the fault address is 0x96000010)
• MMU RAM: 0xBA300000 (Change the most significant 20 bits here to match an unused 4-KB physical region in the memory map)
• MMU Lock: 0x00000400
• MMU LD: 0x00000001

Using the Crash Dump to Find the Location of the Fault

The crash dump call stack can indicate where the crash occurred. Using that information, connect to the remote core with CCS and put a breakpoint in the code at the most recent function in the call stack before the crash. From there, step through the code until the crash happens.

Example – Accessing a Memory Region That is Not Mapped

When using the L2 MMU, every address accessed by the remote core must be mapped. An attempt to access an un-mapped address results in an MMU fault. The following example explores the crash dump of an access to an un-mapped area.

Here is an example fault dump:

From the crash dump, the fault address is 0x96000000. The address will not be found in the resource table, which is why the fault occurred.

Avoid hard-coding of virtual addresses for peripherals and memory blocks with a one-time physical to virtual address lookup using the resource table. There is an API available for this called Resource_physToVirt() in the resource module. This alerts that the address is not mapped in the resource table when the translation fails.

From here, either use the crash dump to see the PC and call stack or follow the instructions under the section “Using CCS to Halt the Code When the Fault Happens.” Error recovery, watchdog timers, and remoteproc autosuspend may need to be disabled to connect CCS. See `Linux and Android - Disabling Error Recovery`_, `Linux and Android – Disabling Watchdog`_, and `Linux and Android - Disabling Remoteproc Auto-Suspend`_ for more information on disabling these.

For this example, use the PC address which, as seen in the crash dump, is at 0xcfa6

[0] [ 107.092] Exception occurred at (PC) = 0000cfa6

Find the corresponding function by looking this address up in the map file for the remote core image. If the PC address is invalid due to an issue such as stack corruption, then this may not yield useful results. In this case, something useful is found:

Alternatively, use CCS to see the location of the fault. If CCS was already connected to the remote core before the fault happened, the core will have halted in the abort function. From here, directly set the PC address and see the line that caused the fault:

Use this technique at any time after booting the remote core to see what a PC address corresponds to. It will display the line that caused the error. This may, however, prevent proper execution because the registers and call stack won’t have proper values.

You can now isolate the particular line in the fxnFault() function that was executing. That code is found in the file <ipc_package>/packages/ti/ipc/tests/fault.c:

case 1:
        System_printf("Generating read MMU Fault...\n");
        a = *(volatile int *) (0x96000000);
        break;

Figure 8 clearly shows what caused the fault in this code, but when it is not clear, use CCS to see the fault in action. Once connected and the symbols are loaded, put a breakpoint in this function (if this function does not happen often). Once the breakpoint is hit, step through the code to find what is causing the fault.

Upon stepping through, observe that the variable, a, is being set to the contents of 0x96000000, which is equal to the fault address. This is the fault in this example.

Next, decide if this is a valid value that needs mapping, or if this is an invalid value that passed due to some error in the code. If it is still not known where the value is coming from, use CCS to trace it back through the call stack to fix the code. If it turns out that the address is an address that must be accessible to the remote core, then map it through the resource table to the appropriate physical memory.