Question about installing the kernel on the Pi 4

Message

jgaz · Post by **jgaz** » Wed Dec 01, 2021 12:59 pm

So, the quick install instructions for the Raspberry Pi https://wiki.gentoo.org/wiki/Raspberry_ ... tall_Guide say to git clone the official kernel from the upstream git project. But, I see sys-boot/raspberrypi-firmware exists. Isn't the kernel already rolled up into that ebuild? Can't I just emerge that instead?

alamahant · Post by **alamahant** » Wed Dec 01, 2021 3:19 pm

Yes
I looked into the ebuild and it apparently installs the files in /boot.
But i couldnt find anything about the actual kernel and the "modules" directory which contains the kernel modules.
Maybe I am mistaken.

The way I do it is

Code: Select all

git clone --depth=1  https://github.com/raspberrypi/firmware
cp -a firmware/boot/* /boot/
cp -a firmware/modules/* /lib/modules/

Then I edit config.txt and optionally cmdline.txt and rebuild my initramfs if any.
For updating the kernel i use

Code: Select all

cp /boot/*.txt /root/
rsync --delete /<src>/ /<dst>/
cp /root/*.txt /boot/

Post by **NeddySeagoon** » Wed Dec 01, 2021 5:42 pm

Moved from Installing Gentoo to Gentoo on ARM.

The Default kernel uses the Powersave CPU governor by default. That clocks the Pi at 600MHz.
You probably want Ondemand.

Firmware means two different things on the Pi4 on all tho other PIs, is means the content of /boot which mostly runs on the GPU before the ARM CPU is allowed to do anything.
It even loads the kernel and initrd, if there is one.

The PI 4 still need most of that but not bootcode.bin.
On the Pi4, bootcode.bin has been replaced with real firmware is an SPI PROM, so the term is ambiguous.

dev-embedded/rpi-eeprom is about updating the SPI PROM 'firmware'.