A previous change added 'console=tty1' to the default kernel command
line on armsr, in order to ensure the framebuffer console is enabled
on systems capable of graphics output.
Unfortunately, this change broke boards that used device tree
(DT) firmware with serial consoles, as the serial console
specified by the system firmware (stdout-path) was no longer
setup by the kernel.
A bit of probing determined that the SPCR (serial port console
direction table) on ACPI systems was preventing Linux from setting
up a default framebuffer console on these systems (which is why
console=tty1 was added).
(The affected ACPI systems are usually VMs using QEMU's
'virt' machine and EDK2 firmware. The firmware on these systems
does not remove the SPCR when a screen is present)
So to ensure all possible systems are setup correctly, we modify
the kernel so all "default" console types (serial and screen)
are setup when no console= arguments are specified on the kernel
command line.
Signed-off-by: Mathew McBride <matt@traverse.com.au>
Fixes: c099523d66 ("use console=tty1 to make console more
readily available")
Link: https://github.com/openwrt/openwrt/pull/17012
Signed-off-by: Robert Marko <robimarko@gmail.com>
(cherry picked from commit 3697022ce3)
Link: https://github.com/openwrt/openwrt/pull/19894
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
20271bf505