Subject: Raspberry Pi 4 Kernel and Boot

From: Chris Johnson <[email-masked]>
Date: Mon, 9 Sep 2019 23:54:40 -0500

I have tried running arm64 rpi alpine 3.10.2 on the Raspberry pi 4
and have found a couple of things that need to be adjusted.

The 3.10.2 release does not boot becuase it is missing a couple of new
files required by the Raspberry pi 4. These two files are:

start4.elf
fixup4.dat

They can be retrieved from the official raspberry pi repository:

https://github.com/raspberrypi/firmware/tree/master/boot

They go in the top level of the fat32(boot) partition of the 3.10.2
release. I do not see an aport that can be patched to include these and
I can not figure out how the releases are generated to create a
patch.

The config.txt needs a couple of modifications, arm_control is being
depreciated, so

arm_control=0x200 needs to be changed to arm_64bit=1

and the following needs to be added

enable_gic=1

I have tested the above changes, and they allow the raspberry pi 4
to boot with current release 3.10.2. However, no usb devices work. This
is because the kernel is not built with the correct defconfig for the
raspberry pi 4. The new defconfig is:

bcm2711_defconfig

I looked at the aport for main/linux-rpi and find it too confusing.
I created an abuild chroot on a 64-bit arm and tried to build it using
bcm2711_defconfig but cannot get past patching. The raspberry pi
specific changes from alpine linux seem to fail when I try to build.

Could these changes be included in the next release to allow the
raspberry pi 4 to work?

Thank you so much for an amazing distro

Sources of information for changes:

Raspberry pi 4 on Ubuntu
https://jamesachambers.com/raspberry-pi-ubuntu-server-18-04-2-installation-guide/

Raspberry pi 4 on Manjaro relase
https://www.manjaro.org/download/arm8-raspberry-pi-4-minimal/
I mounted the fat32 (boot) of the image to see what was going on
I am currently using this and it works flawlessly

Official Raspberry pi documentation
https://www.raspberrypi.org/documentation/configuration/
specifically
https://www.raspberrypi.org/documentation/configuration/boot_folder.md

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From: Natanael Copa <[email-masked]>
Date: Tue, 10 Sep 2019 09:40:14 +0200

Hi!

Thanks for this.

Can you please file an issue on
https://gitlab.alpinelinux.org/alpine/aports/issues with all those
details? It will help us not forget.

Thanks!

-nc

On Mon, 9 Sep 2019 23:54:40 -0500

---

From: Chris Johnson <[email-masked]>
Date: Tue, 10 Sep 2019 04:16:25 -0500

Just filed an issue (#10789).

Thanks!