[WIP] Enable Rockchip arch in kernel

[sambonbonne]

Set CONFIG_ARCH_ROCKCHIP

After some discussion on Matrix about Odroid M1S (based on RK3566), I made this PR to enable Rockchip arch in the kernel.

The goal is to test the generated aarch64 image on my hardware and to see if the initrd size is not increased to much before discussing about the possible inclusion of this configuration in Flatcar.

⚠️ This PR is based on #2300 to use 6.12 kernel, because Odroid M1S support has been added on 6.12, so it can't be merged prior to #2300.

How to use

Installing the image in Odroid M1S requires U-Boot binaries and multiple steps. I will add testing commands if it works on my hardware and someone want to try it on real hardware.

Testing done

No testing for now. I plan to download the generated image (when it's generated) and install it on my hardware to test if it boots.

• Changelog entries added in the respective changelog/ directory (user-facing change, bug fix, security fix, update)
• Inspected CI output for image differences: /boot and /usr size, packages, list files for any missing binaries, kernel modules, config files, kernel modules, etc.

[ader1990]

CONFIG_ARCH_MULTI_V7 might be required too

[sambonbonne]

RK3566 is ARMv8-A (it has only 4 Cortex A-55, which are ARMv8.2-A) and CONFIG_ARCH_MULTI_V7 is for ARMv7 (if I understand correctly). So at first sight, it should not be required but if my real test fails, I'll try to add it.

[ader1990]

See https://cateee.net/lkddb/web-lkddb/ARCH_ROCKCHIP.html: depends on: CONFIG_ARCH_MULTI_V7

[sambonbonne]

Thanks, this is weird because it says it's for Rockchip Cortex-A9 so I'll try without it and if it doesn't work, I'll try to add it.

If I add it, I'll try to use the SDK container to build locally and make the change if it helps.

[ader1990]

@sambonbonne the image was built, you can download it and try it from the github actions artifacts page. https://github.com/flatcar/scripts/actions/runs/12575139169?pr=2556

[github-actions]

Build action triggered: https://github.com/flatcar/scripts/actions/runs/13440424290

[sambonbonne]

@ader1990 thank you! I had some problems when trying to edit the partition layout of my SD card with fdisk on thursday (for U-Boot) and I couldn't try to fix it this week-end but I may have time to work on it on Monday or Tuesday. I already know what I can try to fix my partitioning problem so it should not take too long for me to try.

I understand 3MB is too big, unfortunately I don't know enough about "kernel things" to help on this so if I manage to have a working image, I hope we will be able to reduce the added size or find an alternative.

[sambonbonne]

@ader1990 I'm trying to use flatcar-install /path/to/flatcar_production_image.bin but I have some errors, IDK if I did something wrong. Here are the logs:

$ flatcar-install -d /dev/sdb -B arm64-usr -i /path/to/ignition.json -f /path/to/flatcar_production_image.bin -u
Using existing image: /path/to/flatcar_production_image.bin
Writing /path/to/flatcar_production_image.bin...
Running in chroot, ignoring request.
Running in chroot, ignoring request.
mount: /tmp/flatcar-install.77HskzhsAm/oemfs: WARNING: source write-protected, mounted read-only.
Installing Ignition config /path/to/ignition.json...
cp: cannot create regular file '/tmp/flatcar-install.77HskzhsAm/oemfs/config.ign': Read-only file system
Error: return code 1 from [[ -n "${IGNITION}" ]]
/dev/sdb: 8 bytes were erased at offset 0x00000200 (gpt): 45 46 49 20 50 41 52 54
/dev/sdb: 2 bytes were erased at offset 0x000001fe (PMBR): 55 aa
/dev/sdb: calling ioctl to re-read partition table: Success

If you have any idea to help me, I will be very happy!

[sambonbonne]

@ader1990 I managed to fix my problem and to use flatcar-install with the generated image.

But it seems the first partition, the EFI one, is not mountable when installed so I could not write the boot.scr file. I mounted the partition of the image file to copy the boot.scr before running flatcar-install so I guess it's a workaround but I find it suspicious that the partition is not mountable after dd.

Anyway, the image does not seem to boot so I added CONFIG_ARCH_MULTI_V7 as you recommended but I can't run the pipeline myself. I tried to build using the SDK container but I have some problems when emergeing and I don't have the knowledge to fix it.

Can you launch the pipeline so I can try a new image with the added kernel parameter? Otherwise, should I ask for help with the SDK container (if yes, where? The Matrix channel?)?
Thanks in advance!

Just FYI, here is the boot.txt file I use to generate the boot.scr:

load ${devtype} ${devnum}:1 ${kernel_addr_r} /EFI/boot/bootaa64.efi                                           
bootefi ${kernel_addr_r}  

[ader1990]

@sambonbonne had to solve some conflicts, I did trigger a new build and you should be able to download the image artifact in a few hours, if all goes well.

[sambonbonne]

@ader1990 thanks! I hope the new image will boot. I'll give it a try when I'm able to.

[sambonbonne]

@ader1990 it seems I cannot set CONFIG_ARCH_MULTI_V7, the pipeline for ARM64 failed with:

ERROR: sys-kernel/coreos-modules-6.12.0::coreos-overlay failed (configure phase):
  Requested options not enabled in build:
    CONFIG_ARCH_MULTI_V7

See https://github.com/flatcar/scripts/actions/runs/12743950372/job/35527535677#step:7:4656.

So I guess I can't enable the CONFIG_ARCH_MULTI_V7 option?

[ader1990]

@ader1990 it seems I cannot set CONFIG_ARCH_MULTI_V7, the pipeline for ARM64 failed with:

ERROR: sys-kernel/coreos-modules-6.12.0::coreos-overlay failed (configure phase):
  Requested options not enabled in build:
    CONFIG_ARCH_MULTI_V7

See https://github.com/flatcar/scripts/actions/runs/12743950372/job/35527535677#step:7:4656.

So I guess I can't enable the CONFIG_ARCH_MULTI_V7 option?

it seems that the newer kernel 6.12 does not need it anymore. You can push a new change and I can start the build.

For building the kernel properly with Flatcar, I have the following notes for https://www.flatcar.org/docs/latest/reference/developer-guides/sdk-modifying-flatcar/#getting-started:

./build_packages --board arm64-usr

# make sure the tmp is clean
sudo rm -rf /build/arm64-usr/var/tmp/portage/sys-kernel*

# if the kernel sources have been changed
emerge-arm64-usr sys-kernel/coreos-sources

# if the kernel config or patches have changed
emerge-arm64-usr sys-kernel/coreos-modules

# if the bootengine commit id has changed
emerge-arm64-usr sys-kernel/bootengine

# if the bootengine commit id has changed
sudo rm /build/arm64-usr/usr/share/bootengine/bootengine.cpio
emerge-arm64-usr sys-kernel/coreos-kernel

# do a build packages to make sure
./build_packages --board arm64-usr

# follow the official docs
# https://www.flatcar.org/docs/latest/reference/developer-guides/sdk-modifying-flatcar/#getting-started
# do build_image
# do image_to_vm

[sambonbonne]

Hello @ader1990 and thanks for those details!

I pushed a commit to remove the CONFIG_ARCH_MULTI_V7. I also got the error when trying to build locally.

Speaking of, I tried to build again after removing this config, so I enter the SDK container with ./run_sdk_container -a arm64 -t and run ./build_package --board arm64-usr but I get another error and I don't understand how it's possible, as I use the SDK container:

sys-kernel/coreos-modules-6.12.0 is missing libraries:
	x86_64: libcrypto.so.3
WARNING build_packages: test_image_content: Failed dependency check
WARNING build_packages: This may be the result of having a long-lived SDK with binary
WARNING build_packages: packages that predate portage 2.2.18. If this is the case try:
    emerge-arm64-usr -agkuDN --rebuilt-binaries=y -j9  @world
    emerge-arm64-usr -a --depclean

I will try to run both emerge commands and rebuild but I you think of something else, feel free to tell me.
Edit: I ran both command, both seem to not do anything specific (but succeeded) and the build fails with the same error.

I hope I don't ask for too much with all my questions, to be honest this is my first time building an entire distro, it's challenging and very instructive.

[ader1990]

What usually happens when trying to run build_packages, is that the error is a little up in the logs, and you might need to tee those logs in a file to better search for the error: ./build_packages --board arm64-usr 2>&1 | tee -a build_packages.log.

When I have errors with the build process, I usually start with a very clean environment from scratch, as there might be leftovers or errors introduced by multiple builds. Being a dockerized environment, it is usually easy to create a new env, just remove the cloned repository, do a docker rm of the dangling containers and images, do a docker system prune for safety (of course, make sure you are not using that env for other work), and start over. Always start with a new cloned repo of flatcar/scripts, otherwise you can do a git reset, git clean -fxd, git rebase on flatcar/scripts main branch, and start the process from step 1: ./run_sdk_container -t.

[ader1990]

@sambonbonne image was built here: https://github.com/flatcar/scripts/actions/runs/12845716694

[sambonbonne]

@ader1990 just wanted to tell you I'm still investigating the boot problem.

I tried multiple boot.txt files, even to directly boot vmlinuz-a (with the bootz command) and even that don't work so I think the problem is on U-boot (the difficult part being: I don't have a UART cable so I can't see U-boot logs).

Beside this, I managed to boot MicroOS with this simple boot.txt (using mkimage to make a boot.scr of course):

btrload ${devtype} ${devnum}:${bootpart} ${ramdisk_addr_r} /boot/grub2/arm64-efi/kernel.img
bootm ${ramdisk_addr_r}  

So I know U-Boot is capable of booting a working OS, I just don't know why it doesn't boot Flatcar.

Edit: I just decided to order a serial cable to see if U-Boot logs message to the UART port, it may take some time to arrive but I still want to work on this.

[sambonbonne]

Latest push is due to me rebasing this branch from ader1990/linux_kernel_6_10 and removing the commits which added then removed CONFIG_ARCH_MULTI_V7. No need to rebuild for now.

[sambonbonne]

Good news: I got my cable and I already have some things.

Bad news: right now, it's still complicated to find why Flatcar doesn't boot.

I can see the Grub menu through the serial port but after booting Flatcar, even by adding a debug parameter, all I get is:

Booting a command list

EFI stub: Booting Linux Kernel...
EFI stub: EFI_RNG_PROTOCOL unavailable
EFI stub: Using DTB from configuration table
EFI stub: Exiting boot services...

I also tried to boot the A partition directly (still from Grub menu) with the debug parameter, nothing more than the above logs.

I think I miss a kernel configuration, I'm looking for it. Fortunately, Home Assistant provides a working image for Odroid M1S so I will try to find out what they use. I hope I'll be able to build locally this time, this would avoid multiple pipelines just to find out missing parameters.
I guess this will increase the initrd size but let's find out the config, then we'll see.

[ader1990]

I see that the support has been there since the 6.12 torvalds/linux@10dc64f, so it should work. For the debug logs, I might suggest adding more kernel config params - mainly console=ttyAMA0 console=ttyAMA1 console=ttyS0 console=ttyS1, maybe you can get some more information. Also, it would be helpful to share a kernel config file from an image that works, to cross-compare and see what might be missing.

Thanks.

[sambonbonne]

My comment is a bit long so I tried to structure it two parts.

Debug

I tried different parameters for debug logs: the four console=… you gave and console=tty0 (this last was tried because I found it in the boot partition of the HAOS image): I get nothing. I tried in the default entry and in the A partition entry.

Maybe I do it wrong but it's not my first time adding a temporary kernel parameter from Grub: I use cu as a serial console, I some Odroid boot information, then I have the Grub menu. I edit the first entry, append the parameter at the end of the line starting with linux and ending with $linux_cmdline and hit Ctrl-x to boot.

Kernel configs

As a theoretically working kernel config, I have two sources for Odroid M1S:

• Gentoo wiki: https://wiki.gentoo.org/wiki/Hardkernel_ODROID-M1S#Kernel_building
• Home Assistant: https://www.home-assistant.io/installation/odroid/#flashing-home-assistant-m1s

Gentoo wiki configs try

I tried to add configs from Gentoo wiki but that's where I got some build error when running build_packages from my machine. I pulled my branch since you rebased it on main (thanks for that) but now I have a new build error, from podman, the podman's build log (in /build/arm64-usr/var/log/portage/app-containers:podman-5.3.0:20250212-102732.log) just ends with this:

/build/arm64-usr/var/log/portage/app-containers:podman-5.3.0:20250212-102732.log

cd .                                                                                                                                                                                         
GOROOT='/usr/lib/go' /usr/lib/go/pkg/tool/linux_amd64/link -o $WORK/b001/exe/a.out -importcfg $WORK/b001/importcfg.link -installsuffix shared -X=runtime.godebugDefault=asynctimerchan=1,goty
pesalias=0,httpservecontentkeepheaders=1,tls3des=1,tlskyber=0,x509keypairleaf=0,x509negativeserial=1 -buildmode=pie -buildid=Di7VbJOVEz0cCecPSPVh/lIE-3YL_RKIYFm-tCLNS/g5oi0ADpMmXJOtBy8UrJ/D
i7VbJOVEz0cCecPSPVh -X github.com/containers/podman/v5/libpod/define.buildInfo=1739356126 -X github.com/containers/podman/v5/libpod/config._installPrefix=/usr -X github.com/containers/podma
n/v5/libpod/config._etcDir=/etc -X github.com/containers/podman/v5/pkg/systemd/quadlet._binDir=/usr/bin -X github.com/containers/common/pkg/config.additionalHelperBinariesDir= -extld=aarch6
4-cros-linux-gnu-gcc $WORK/b001/_pkg_.a                                                                                                                                                      
/usr/lib/go/pkg/tool/linux_amd64/buildid -w $WORK/b001/exe/a.out # internal                                                                                                                  
mkdir -p bin/                                                                                                                                                                                
cp $WORK/b001/exe/a.out bin/podman-testing                                                                                                                                                   
/usr/lib/go/pkg/tool/linux_amd64/buildid -w $WORK/b001/exe/a.out # internal                                                                                                                  
mkdir -p bin/                                                                                                                                                                                
cp $WORK/b001/exe/a.out bin/podman                                                                                                                                                           
test -z "" || chcon -t container_runtime_exec_t bin/podman                                                                                                                                      

I built from a fresh environment (new clone and remove all Flatcar containers and images) so I don't understand how I can still face this kind of errors (I run the ./build_package --board arm64-usr from the SDK container, run with ./run_sdk_container -a arm64 -t).

Is it possible to build a smaller set just to try the boot, without Podman for example?

Home Assistant OS info

For HAOSS (short for Home Assistant OS), it bootloops when installed on SD card so I may have to try to install it directly on eMMC and maybe I can find a way to copy the /proc/config.gz to check if there is useful kernel parameters. But even if I find other kernel parameters to add, I may face build errors.

[sambonbonne]

I managed to build with more parameters but still no luck. I created a PR on my repo for that and started a self-hosted runner with the required labels.

Build working but image still not booting: sambonbonne@1eb4d0b

Build failing: sambonbonne@98c0da9 (build log: https://github.com/sambonbonne/flatcar-scripts/actions/runs/13437246231/job/37542450165)

My next try, when I have the time, will be to run the HAOSS image directly in eMMC (instead of SD) and see if the kernel config is available. 🤞

[chewi]

Just to let you know that we do want to support this eventually. I'm hard at work on addressing the lack of space in /boot, which we need to fix before we can enable Rockchip support.

[sambonbonne]

@chewi I'm happy to know you want to support this when it's possible, I would have been very frustrated if I did this die-and-retry process for nothing 😁

But I understand the priority is on /boot space, Adrian explained the problem and I perfectly understand. This let me some time to try different things in this PR.

[sambonbonne]

Good news: I managed to boot HAOS, dump the /proc/config.gz and, of course, gunzip it. The text file is 10760 lines long (with comments and spacing but still, I guess this is the expected amount of lines for a Linux kernel).

Bad news: they are on kernel 6.6.73, so I guess they use some patches to make the Odroid M1S work.

I'll try to build my branch with their config file anyway in a few days.

Does anyone know if there is a way to check if a config has been renamed between two kernel versions (especially from 6.6 to 6.12)?

[chewi]

Do you mean config options changing name? I have a git clone of the kernel, so I'd check the history, but make oldconfig is very useful too. It'll ask about options that aren't in your config.