[Bug 2073835] Re: Default kernel commandline options on Raspberry Pi

[Juerg Haefliger]

> boot.scr is only relevant when booting via U-Boot. In this case
/boot/firmware/cmdline.txt is not considered.

I don't think that's entirely correct. The Pi firmware loads the options
from /boot/firmware/cmdline.txt and patches the in-memory DT (I believe)
from which u-boot gets the chosen args and then appends 'quiet splash'
to that:

U-Boot> fdt addr ${fdt_addr}
U-Boot> fdt move ${fdt_addr} ${fdt_addr_r}
U-Boot> fdt get value bootargs /chosen bootargs
U-Boot> env print bootargs
bootargs=coherent_pool=1M snd_bcm2835.enable_compat_alsa=0 snd_bcm2835.enable_hdmi=1 video=Composite-1:720x480 at 60i,margin_left=32,margin_right=32,margin_top=32,margin_bottom=32 smsc95xx.macaddr=B8:27:EB:97:40:CC vc_mem.mem_base=0x3ec00000 vc_mem.mem_size=0x40000000  dwc_otg.lpm_enable=0 elevator=deadline rng_core.default_quality=700 vt.handoff=2 console=tty1 console=ttyAMA0,115200 ignore_loglevel

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to flash-kernel in Ubuntu.
https://bugs.launchpad.net/bugs/2073835

Title:
  Default kernel commandline options on Raspberry Pi

Status in flash-kernel package in Ubuntu:
  New

Bug description:
  This is Pi specific. The problem is that in older releases where we
  use u-boot in the Ubuntu raspi images, flash-kernel uses default
  kernel commandline options 'quiet splash' (from /usr/share/flash-
  kernel/default/flash-kernel) which end up hard-coded in
  /boot/firmware/boot.scr, specifically this line:

  setenv bootargs " ${bootargs} quiet splash"

  This line basically extends the kernel commandline options specified
  in /boot/firmware/cmdline.txt. On Pi, there should only be one place
  to specify kernel options and that's cmdline.txt, u-boot/flash-kernel
  should not modify or extend these options.

  We recently had a customer issue where we needed to enable kernel
  logging over the serial console which required modification of
  cmdline.txt *and* rebuilding boot.scr to drop 'quiet splash'. We
  should not have to touch boot.scr for this.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/flash-kernel/+bug/2073835/+subscriptions