Re: [PATCH v5 0/4] Add minimal boot support for Raspberry Pi 5

From: Stefan Wahren
Date: Fri May 31 2024 - 06:00:41 EST


Hi Andrea,

Am 30.05.24 um 12:11 schrieb Andrea della Porta:
Hi,

This patchset adds minimal support for the Broadcom BCM2712 SoC and for
the on-board SDHCI controller on Broadcom BCM2712 in order to make it
possible to boot (particularly) a Raspberry Pi 5 from SD card and get a
console through uart.
Changes to arm64/defconfig are not needed since the actual options work
as they are.
This work is heavily based on downstream contributions.

Tested on Tumbleweed substituting the stock kernel with upstream one,
either chainloading uboot+grub+kernel or directly booting the kernel
from 1st stage bootloader. Steps to reproduce:
- prepare an SD card from a Raspberry enabled raw image, mount the first
FAT partition.
- make sure the FAT partition is big enough to contain the kernel,
anything bigger than 64Mb is usually enough, depending on your kernel
config options.
- build the kernel and dtbs making sure that the support for your root
fs type is compiled as builtin.
- copy the kernel image in your FAT partition overwriting the older one
(e.g. kernel*.img for Raspberry Pi OS or u-boot.bin for Tumbleweed).
- copy arch/arm64/boot/dts/broadcom/bcm2712-rpi-5-b.dtb on FAT partition.
- make sure you have a cmdline.txt file in FAT partition with the
following content:
# cat /boot/efi/cmdline.txt
root=/dev/mmcblk0p3 rootwait rw console=tty ignore_loglevel earlycon
console=ttyAMA10,115200
- if you experience random SD issues during boot, try to set
initial_turbo=0 in config.txt.
was this an issue since the beginning of this series?

What kind of SD issues?

Is there a downstream reference?