Re: [DistroKit] [ptxdist] Prepare Image for Raspberry Pi 4

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

Hello Pranay,

On 28.10.22 14:47, Joshi, Pranay wrote:
> Hi Michael,
> 
> Thank you for your support.
> 
> Earlier we were stuck in building toolchain and root filesystem for Raspberry Pi platform using PTXDist Tool, OSELAS Toolchain and DistroKit. We have been successfully able to prepare an image with the solutions provided by you.

Cc += DistroKit Mailing List <distrokit@pengutronix.de>

The PTXdist mailing list is rather for the build system itself, toolchain
and upstream rules and not about particular board support packages.

> We tried prepared image over RPi 4, once we have powered up RPi 4 it is showing an error like "This board requires newer software".
> 
> After some inspection we understood that the prepared image can support RPi 3.

The DistroKit "next" branch supports Raspberry Pi 4 in 32-bit mode. The changes are not yet
in "master". The resulting image can be installed on Rasperry Pi 2, 3, CM3 and 4. Keep in mind
that I did not test rpi4 support on a CM4. It may need some slight tweaking.  

> Now can you please give some path to prepare supported image for RPi 4 using PTXDist tool?
> 
> From where can we get an idea to modify an image for a new platform like RPi 4 using PTXDist?

If you are willing to help, adding support for Raspberry Pi 3 and 4 64-bit to DistroKit
platform-v8a should be quite straight-forward. All components built by platform-v7a for
Raspberry Pi can be configured for 64-bit (bootloader, kernel, rootfs, rpi firmware),
but some integration into DistroKit is still required:

  - Add a new barebox-rpi.{make,in} rule to platform-v8a, which collects the same files
    as barebox-rpi2.make in platform-v7a. platform-v7a has barebox-common, but we don't
    have that for platform-v8a, so either add it or add it as a standalone rule

  - copy the barebox-rpi3.config to platform-v8a and change it to have CONFIG_64BIT=y

  - configure the kernel to enable all the Raspberry Pi 4 related drivers

  - Have DistroKit build the Raspberry Pi 4 device trees and generate bootspec entries using
    them

  - ensure config.txt has arm_64bit=1

  - Add image recipes that pull in the firmware, bootloader and rootfs

When done correctly, you will end up with a rpi.hdimg that can be booted from SD
on either Rpi3 or Rpi4.

Cheers,
Ahmad

> 
> 
> Pranay Joshi
> 
> Lead Engineer-Firmware Engineering
> 
> Drilling Services
> 
> Baker Hughes
> 
> 
> 

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