Commonly used kernel parameters
microsoft-surface-rt.dtb
for APX booting
microsoft-surface-rt-efi.dtb
for EFI booting
Specifies the root filesystem which should be used.
/dev/mmcblk0pN
eMMC partition N
/dev/mmcblk1pN
µSD Card partition N
/dev/sdaN
USB partition N
tty0
for normal console (internal screen+tCover/USB keyboard)
ttyS0,115200n8
for serial console at 115200 Baud, no parity bit, 8bits (need uart access)
You can specify multiple console= options on the kernel command line. Output will appear on all of them. The last device will be used when you open /dev/console
. So, for example:
defines that opening /dev/console
will get you the current foreground virtual console, and kernel messages will appear on both the VGA console and the 2nd serial port (ttyS1 or COM2) at 9600 baud.
Note that you can only define one console per device type (serial, video). - https://www.kernel.org/doc/html/latest/admin-guide/serial-console.html
Waits for root filesystem. Some root filesystems will be mounted after the kernel finished initalizing hardware. Thats the case for USB. eMMC/SD seems to work without this parameter.
EFI doesn't support CPU idle therefore it must be disabled for efi booting. You shouldn't use this param for APX booting.