3.4. Android on SD Card¶

This applications Notes contains step to use SD Card instead of EMMC.

3.4.1. Build U-Boot with this changes¶

Apply this patch in U-boot source code:

diff --git a/configs/am62x_evm_a53_defconfig b/configs/am62x_evm_a53_defconfig
index 51f7ea5ab9..aa7f7372d0 100644
--- a/configs/am62x_evm_a53_defconfig
+++ b/configs/am62x_evm_a53_defconfig
@@ -96,7 +96,7 @@ CONFIG_USB_FUNCTION_FASTBOOT=y
CONFIG_FASTBOOT_BUF_ADDR=0xC0000000
CONFIG_FASTBOOT_BUF_SIZE=0x2F000000
CONFIG_FASTBOOT_FLASH=y
-CONFIG_FASTBOOT_FLASH_MMC_DEV=0
+CONFIG_FASTBOOT_FLASH_MMC_DEV=1
CONFIG_FASTBOOT_CMD_OEM_FORMAT=y
CONFIG_TI_SCI_PROTOCOL=y
CONFIG_DM_I2C=y

Follow this link to build U-Boot.

Rebuild U-boot then copy u-boot.img in Android build system environment : vendor/ti/am62x/bootloader/am62-sk

Follow this link to build Android image. Go in your Android environment then rebuild with TARGET_SDCARD_BOOT=true build args:

cd ${YOUR_PATH}/ti-aosp-12
lunch <BUILD_TARGET>
m TARGET_SDCARD_BOOT=true

Warning

Minimal size for SD card is 16GB

Change the Boot Mode DIP switches to SD card boot mode.
Boot mode DIP Switch: SW1: 11000010 SW2: 01000000

Go in out dir in android environment and launch this command:

# If you are using binaries built locally
cd out/target/product/am62x
sudo ./flashall.sh --sdcard="/dev/sdX"

flashall.sh script print in your console instruction to do

Note

Replace X in /dev/sdX/ by letter corresponding to your SDCard