4.3. OSAL¶
4.3.1. Introduction¶
The OSAL library provides operating system abstraction layer API sample implementations that are required for processor SDK drivers. Scope of APIs supported in the module is limited to support OS services required for RTOS or bare metal drivers
- Supported Operating Systems
- FreeRTOS
- Non-OS (Baremetal)
- Supported SOCs
- Please refer to component release notes
4.3.2. User Interface¶
For details about individual fields of this library structure, see the PDK doxygen documentation / OSAL API Guide
4.3.2.1. APIs¶
Porting of OSAL component will enable extending PDK components to additional OS environment. Reference top level API header file includes:
#include <ti/osal/osal.h>
The following table shows which all OSAL modules are supported for FreeRTOS and Non-OS. Using OSAL APIs that are not supported for an OS will result in linking errors.
| OSAL Module | FreeRTOS | Non-OS(Baremetal) |
|---|---|---|
| Tasks (TaskP) | YES | NO |
| Semaphores (SempahoreP) | YES | YES |
| HW Interrupts (HwiP) | YES | YES |
| HW Timers (TimerP) | YES | YES |
| Cache Ops (CahceP) | YES | YES |
| Cycle profiler (CycleProfilerP) | YES | YES |
| SW Timer (ClockP) | YES | NO |
| Events (EventP) | YES | NO |
| SW Mailbox (MailboxP) | YES | NO |
| Mutex (MutexP) | YES | NO |
| Queue (QueueP) | YES | NO |
| Arbitrary Heap (HeapP) | YES | NO |
| Task/CPU Load (LoadP) | YES | NO |
| SW Interrupts (SwiP) | NO | NO |
In case of FreeRTOS/Non-OS, static memory allocation is done inside the osal library for all the modules.
The static memory allocation for SemaphoreP and HwiP are scalable if needed by the application users, especially when the create APIs fail to create the SemaphoreP and HwiP handles. (Indicated by NULL handle values).
The application can provide a continuous segment of external memory for SemaphoreP as below.
- Get the current OSAL attributes
...
osal_ret = Osal_getHwAttrs(&hwAttrs);
- Set the continuous external memory block address and size
...
hwAttrs.extSemaphorePBlock.base = (uintptr_t) &semPMemBlock[0];
...
hwAttrs.extSemaphorePBlock.size = SEMP_BLOCK_SIZE;
...
ctrlBitMap = OSAL_HWATTR_SET_SEMP_EXT_BASE;
...
osal_ret = Osal_setHwAttrs(ctrlBitMap, &hwAttrs);
The application can provide a continuous segment of external memory for HwiP as below.
- Get the current OSAL attributes
...
osal_ret = Osal_getHwAttrs(&hwAttrs);
- Set the continuous external memory block address and size
...
hwAttrs.extSemaphorePBlock.base = (uintptr_t) &hwiPMemBlock[0];
...
hwAttrs.extSemaphorePBlock.size = HWIP_BLOCK_SIZE;
...
ctrlBitMap = OSAL_HWATTR_SET_HWIP_EXT_BASE;
...
osal_ret = Osal_setHwAttrs(ctrlBitMap, &hwAttrs);
4.3.2.2. Application Integration Details¶
Baremetal or Non-OS Use case
Reference library path to be included in application build environment:
<ti/osal/lib/nonos/[soc]/[[cpu]/>
FreeRTOS based application
Reference library path to be included in application build environment:
<ti/osal/lib/freertos/[soc]/[[cpu]/>
4.3.3. Application¶
4.3.3.1. Examples¶
OSAL Unit Test
Application Name
| Example | FreeRTOS | Non-OS(Baremetal) |
|---|---|---|
| Unit Test | OSAL_TestApp_freertos | OSAL_Baremetal_TestApp |
Description
The unit testapp tests all the supported OSAL modules for an OS and prints output on UART console.
Expected Results
The output for each of the tests (Hwi, Timer, Delay, Semaphores etc) can be seen on the UART console like
<Module> tests have passed.
After a successful run following will also be displayed on the UART console.
All tests have passed.