SK-AM64: SKAM64 -A (multiple core loading)

shruti gupta

Part Number: SK-AM64

Hi ,

Is it possible to load multiple cores in skam64 at the same time , or to load one arm core from the other arm core like we can do with the R5F and PRU........for example if I consider R5F0 as my main core , and another R5F1 as my remote core so is there a way to load the remote core from the main core , instead of loading it manually ? my use case is I have multiple things to process and for each parameter I want to use a different core for computation. I was checking the example code given in the SDK for IPC notify echo , there it was mentioned that for a multicore program all the executables need to be loaded and run , can this loading be done from a single core or in other words , is there a way to flash multiple SOC initialization binaries at once ?

Regards,

Shruti Gupta

over 2 years ago

0 Nick Saulnier over 2 years ago

TI__Guru* 97010 points

Hello Shruti,

How are you booting your board?

The SBL boot method found in MCU+ SDK will initialize multiple remote cores before Linux boot happens. The SPL boot method that is the default in the Linux SDK uses the Linux RemoteProc driver to initialize remote cores during Linux boot. For both boot methods, all cores that are enabled will be initialized (though not at literally the exact same nanosecond).

Another question: What do you mean by "at the same time" (i.e., do you care about a specific window of time?) If you are trying to initialize multiple cores within a specific time window, what are you trying to accomplish by doing that?

Regards,

Nick

0 shruti gupta over 2 years ago in reply to Nick Saulnier

TI__Genius 9540 points

Hi Nick ,

Thanks for the response , so yes I have a test time of 3 seconds , out of which I will be doing the data capture and the processing on the data within 2 seconds , so for that I need to synchronize multiple cores , to start the capture and processing at the same time , I'm not using Linux , using the freertos for my program , sharing here a brief overview of what I want to achieve , hope that helps to understand the use case in a better way

0 Prashant Shivhare over 2 years ago in reply to shruti gupta

TI__Guru 64261 points

Hi Shruti,

Do you have the executables for each core & looking to boot all these at a time? If so, you could create an Appimage which will contain executables for each core. Then, the SBL at run time will parse this Appimage & load the executables for each core. At the end, the SBL will run these cores one by one.

Regards,

Prashant

0 shruti gupta over 2 years ago in reply to Prashant Shivhare

TI__Genius 9540 points

Hi Prashanth ,

I do have binaries (.out files ) for every core which I want to use , do you have any documents which I can refer to create the app image including multiple cores ? I think what you are suggesting will work for my use case.

0 Prashant Shivhare over 2 years ago in reply to shruti gupta

TI__Guru 64261 points

Hi Shruti,

For your use case, you can refer to the "Out2RPRC" & "Multi-core Image Gen" sections of the following guide: https://software-dl.ti.com/mcu-plus-sdk/esd/AM64X/08_04_00_17/exports/docs/api_guide_am64x/TOOLS_BOOT.html

Basically, the steps are:

Convert each .out file to .rprc files using the elf2rprc tool.
Take each .rprc file & package them together into one .appimage file using multicoreImageGen tool.

If you are using the default makefile of an example, then you also don't need to do the first step as the makefile will generate the .rprc file as part of the build process. You can then take these .rprc files & generate the final .appimage by yourself.

In case of doubts in the second step, you may refer to the below FAQ also.

https://e2e.ti.com/.../faq-am6442-am64x-multi-core-image-gen-for-gp-and-hs---fs-hw-versions

Regards,

Prashant

0 shruti gupta over 2 years ago in reply to Prashant Shivhare

TI__Genius 9540 points

Thanks Prashanth , will check these documents

0 shruti gupta over 2 years ago in reply to Prashant Shivhare

TI__Genius 9540 points

Hi Prashanth,

is there a specific sequence in which the cores are getting loaded like if it depends on the core id ...from my observation it is coming out like that only , can you confirm if it is correct or not?

+1 Prashant Shivhare over 2 years ago in reply to shruti gupta

TI__Guru 64261 points

Hi Shruti,

I believe there is no specific sequence one has to follow. The loading of the executables can be done in any order. And when it's time to run the cores, all the cores except R5FSS0 must be run before & then at the end the R5FSS0 self-resets & passes the control to the R5FSS0 application.

I check the SBL_OSPI & see that the order is: M4F -> R5FSS1 -> A53 -> R5FSS0. If this order does not meet your use case, you can modify the SBL to change the order.

Regards,

Prashant

0 Nick Saulnier over 2 years ago in reply to Prashant Shivhare

TI__Guru* 97010 points

Commenting from the Linux terminal side for future readers:

the mapping of /sys/class/remoteproc/remoteprocX to a specific processor is not fixed. I expect this to be true regardless of whether MCU+ SBL initializes the remote cores, or the Linux RemoteProc driver initializes the remote cores. (e.g., R5F0_0 may be remoteproc0 one boot, and remoteproc1 on a different boot)

Please check the name of the remoteproc before starting to interact with it through the Linux terminal. For more information, reference https://dev.ti.com/tirex/explore/node?a=7qm9DIS__LATEST&node=A__ANKEb6LZY6VAX.9xvGwQ-g__linux_academy_am64x__7qm9DIS__LATEST

Regards,

Nick

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SK-AM64: SKAM64 -A (multiple core loading)