[FAQ] TDA4VH-Q1: How to change the ATF to print on MCU_UART in SBL bootflow

Initially, you would create the binaries required for BootApp referring the below steps "Booting Linux via MMCSD"

https://software-dl.ti.com/jacinto7/esd/processor-sdk-rtos-j784s4/09_02_00_05/exports/docs/pdk_j784s4_09_02_00_30/docs/userguide/j784s4/boot/boot_app.html

If you are loading vision_apps binaries, then you could refer the below FAQ instead

https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1332298/faq-tda4vl-q1-run-vision_apps-in-sbl-boot-flow-with-bootapp-image

On the EVM, you would see the logs of SBL on MCU_UART 0 and ATF, OPTEE and Linux logs on Main UART 8

Any change in the custom board UART would require a rebuild of the firmwares with the specific UART port

This FAQ focused on changing the UART instance to MCU_UART for ATF

Step 1: Change the K3_USART_BASE and K3_USART_CLK_SPEED in ${PSDKLA}/board-support/trusted-firmware-a-2.10+git/plat/ti/k3/include/platform_def.h

  For mcu uart, it would be K3_USART_BASE 0x40a00000 and K3_USART_CLK_SPEED   96000000

Step 2: Rebuild the ATF firmware using the below command removing optee

make CROSS_COMPILE="${PSDKLA}/linux-devkit/sysroots/x86_64-arago-linux/usr/bin/aarch64-oe-linux/aarch64-oe-linux-" ARCH=aarch64 PLAT=k3 TARGET_BOARD=j784s4

Step 3: Copy the generated b31.bin to ${PSDKLA}/board-support/prebuilt-images

Step 4: Replace the below file "atf_optee.lds" in ${PSDKRA}/mcusw/mcuss_demos/boot_app_mcu_rtos/main_domain_apps/scripts/hlos/linux/atf_optee.lds

/cfs-file/__key/communityserver-discussions-components-files/791/atf_5F00_optee.lds

Step 5: Follow the "Steps to generate Linux related images" in the below FAQ

https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1332298/faq-tda4vl-q1-run-vision_apps-in-sbl-boot-flow-with-bootapp-image

Step 6: Replace the generated atf_optee.appimage in the SD Card and boot the same.

Now the ATF logs would be seen on the MCU_UART

Regards,

Nikhil