AM6548: SPL manual R5 app loading doesn't seem to work

Huichun Feng

Part Number: AM6548

Hi,

I'm trying to do manual loading of LED blink example at u-boot prompt, the load has successed, but the R5 doesn't seem to work (the LEDs didn't blink and UART has no output) after issuing "rproc start 0" (no error reported), Is there anything I misunderstood?

Specifically, I did the following:

Download and install "ti-processor-sdk-rtos-am65xx-evm-08_02_00_05-linux-x64-installer.run" (i.e. version 08_02_00_05 of RTOS SDK).
In the RTOS SDK, navigate to "pdk_am65xx_08_02_00_21/packages/ti/drv/gpio/test/led_blink".
Build the example with command "make BOARD=am65xx_idk CORE=mcu1_0 BUILD_OS_TYPE=baremetal"
Copy "pdk_am65xx_08_02_00_21/packages/ti/binary/GPIO_LedBlink_TestApp_freertos/bin/am65xx_idk/GPIO_LedBlink_TestApp_freertos_mcu1_0_release_strip.xer5f" into the boot partition of the SD card.
In SPL, init the rproc with "rproc init".
Load the ELF with "fatload mmc 1 0x90000000 GPIO_LedBlink_TestApp_freertos_mcu1_0_release_strip.xer5f"
Load the ELF into R5 with "rproc load 0 0x90000000 0x${filesize}"
Start R5 with "rproc start 0"

Nothing happened after step 8, even after issuing "boot" in u-boot. Thereotically, the LED should blinking as the same as CCS loads the same app. Would it be the difference of SPL?

PS1 The current SPL is coming from the "default image" of Linux-RT SDK, namely version 08.06.00.47 of Linux-RT SDK. The flash is performed by script "create-sdcard.sh".

PS2 Step 7 returns "Load Remote Processor 0 with data@addr=0x90000000 70724 bytes: Success!".

PS3 My board is the official one, AM65x IDK.

Thanks!

7 months ago

+1 Nick Saulnier 7 months ago

TI__Guru* 76425 points

Hello,

Can you please show your terminal output for going through the steps at
https://software-dl.ti.com/processor-sdk-linux/esd/AM65X/08_02_00_02/exports/docs/linux/Foundational_Components/U-Boot/UG-RemoteProc.html ?

Just to make sure there isn't something we would not expect.

Just because peripherals are not responding, does not necessarily mean that the firmware failed to load. There could be other factors, e.g. if that peripheral was already grabbed by uboot.

The first thing I would try to do is connect to the remote core with CCS to see what the core is doing. If needed, you could add software breakpoints into your code to control where in the program the code it.

This looks like a starting point for connecting CCS to the processor (though you wouldn't care about connecting to the SPL in this case):
https://software-dl.ti.com/processor-sdk-linux/esd/docs/06_03_00_106/linux/Foundational_Components_U-Boot.html#uboot-spl-debugging-tips

Another helpful note for connecting CCS to a remote core that was already initialized (in this case, by Uboot) is here:
https://dev.ti.com/tirex/explore/node?node=A__AVn3JGT9fqm0PbS.pegO-g__AM62-ACADEMY__uiYMDcq__LATEST
section "Debug the remote core program from CCS while Linux is running"

That doc was written for AM62x, but the concept of that section should apply to AM65x.

If CCS doesn't work easily, we could also try doing something like writing to a known area of memory with the R5F program and reading it from uboot to see if the R5F firmware actually executed the "memory write" instruction, but I would try getting the CCS connection working first.

Regards,
Nick

0 Huichun Feng 7 months ago in reply to Nick Saulnier

Prodigy 81 points

Thanks for the info! The LED worked after using the executable (.out) built from the MCU SDK, which is also an ELF (checked with command "file <exec_filename>"). Do you know the difference between .out and .xer5f ELFs?

Thanks!

Huichun

0 Nick Saulnier 7 months ago in reply to Huichun Feng

TI__Guru* 76425 points

edited Dec 6 2023

Hello Huichun,

Glad to hear that building the project from the MCU SDK creates an output file that works as expected!

Should there be a difference between .out and .xer5f binaries?

As far as I am aware, there should not be any differences between ELF files with those two different extensions. See this e2e for a discussion of why the SDK's prebuilt binaries are .xer5f instead of .out, and whether there are any differences:
https://e2e.ti.com/support/processors-group/processors/f/processors-forum/835734/ccs-am6548-generating-xer5f-files-for-r5/3090803#3090803

Let's check for bugs

I am not very familiar with the AM65x PDK / TI_RTOS SDK (SDK 8.2). With the latest RTOS release, we moved AM65x to the same FreeRTOS that we are using on our other parts, the MCU+ SDK 9.1.

https://www.ti.com/tool/download/MCU-PLUS-SDK-AM65X
https://www.ti.com/tool/download/PROCESSOR-SDK-RTOS-AM65X

But let's do a quick sanity check to see if it looks like there is a bug with the PDK system.

1) Were both the .out file and the .xer5f file in the same output folder? If not, where were the outputs?

2) Did both output files seem to be identical? (e.g., same size?)

Regards,

Nick

0 Nick Saulnier 7 months ago in reply to Nick Saulnier

TI__Guru* 76425 points

Hello Huichun,

Ahh, after reading your other thread I see when you say "MCU SDK", you are referring to the MCU+ SDK 9.1.

https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1298904/am6548-sbl-doesn-t-load-appimage-from-pdk-example

That would be a lot harder to directly compare the projects. Please ignore the "check for bugs" part of my previous response.

Regards,

Nick

0 Huichun Feng 7 months ago in reply to Nick Saulnier

Prodigy 81 points

Hello Nick,

FWIW, in PDK, the .xer5f and .out files are not in the same folder. Actually, I didn't find .out file in PDK build.

Thanks,

Huichun

0 Nick Saulnier 7 months ago in reply to Huichun Feng

TI__Guru* 76425 points

Hello Huichun,

I will treat this thread as closed. Let us know if additional work is required on this thread.

Regards,

Nick

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AM6548: SPL manual R5 app loading doesn't seem to work