[Pkg-raspi-maintainers] Bug#1055084: Bug#1055084: raspi-firmware: Raspberry Pi 4 fails to boot 6.1.0-13-arm64 reliably (detects /dev/mmcblk0 instead of mmcblk1)

[Lucas Nussbaum]

On 31/10/23 at 10:44 +0100, Cyril Brulebois wrote:
> Hi Lucas,
> 
> Lucas Nussbaum <lucas at debian.org> (2023-10-31):
> > After upgrading my RPI4 to bookworm, it no longer boots reliably.
> > Sometimes the SD card gets detected as mmcblk0, sometimes as mmcblk1,
> > causing the initramfs to fail to find the root filesystem.
> > 
> > Going back to the bullseye kernel (5.10.0-26-arm64) makes it boot
> > reliably, detecting the SD card as mmcblk1.
> 
> Using label-based booting makes this issue go away:
>   https://salsa.debian.org/raspi-team/image-specs/-/commit/f89f71560d2ca1bd60d97dbb26b89782657d56ae
> 
> Before this commit, the first few boots would happen with a label-based
> booting, but that would go away as soon as the raspi-firmware hook would
> run, leaving you to get either mmcblk0 or mmcblk1 at boot-up.
> 
> I only observed that on the Pi 4 family (Pi 4 and Compute Module 4), and
> I'm not sure this is directly linked to the Linux version. (I've had a
> lot of back and forth due to heavy debugging so I don't recall coming to
> a conclusion for that one except “use labels, always”.)

Thanks!

So, assuming there's a specific issue when upgrading from bullseye to
bookworm (which I believe but I'm not 100% sure), this would affect
upgrades but not new installs, since new installs now use partition
labels.

For reference, to fix this, I did:
# check that I use labels
lsblk -o name,mountpoint,label,size,uuid
# edit /etc/default/raspi-firmware
sed -i 's/^#ROOTPART=.*/ROOTPART=LABEL=RASPIROOT/' /etc/default/raspi-firmware
# apply changes to cmdline.txt
dpkg-reconfigure raspi-firmware
# check that cmdline.txt looks good
# reboot

Lucas