Le 25/03/2021 à 20:32, Will Deacon a écrit :

On Thu, Mar 25, 2021 at 12:18:38PM +0100, Christophe Leroy wrote:

quoted

- For ARM it means to append the bootloader arguments to the CONFIG_CMDLINE
- For Powerpc it means to append the CONFIG_CMDLINE to the bootloader arguments
- For SH  it means to append the CONFIG_CMDLINE to the bootloader arguments
- For EFI it means to append the bootloader arguments to the CONFIG_CMDLINE
- For OF it means to append the CONFIG_CMDLINE to the bootloader arguments

So what happens on ARM for instance when it selects CONFIG_OF for instance ?

I think ARM gets different behaviour depending on whether it uses ATAGs or
FDT.

As far as I can see, ARM uses either ATAGs only or both ATAGs and FDT. ATAGs is forced to 'y' when 
USE_OF is set. Do I miss something ?

quoted

Or should we consider that EXTEND means APPEND or PREPEND, no matter which ?
Because EXTEND is for instance used for:

	config INITRAMFS_FORCE
		bool "Ignore the initramfs passed by the bootloader"
		depends on CMDLINE_EXTEND || CMDLINE_FORCE

Oh man, I didn't spot that one :(

I think I would make the generic options explicit: either APPEND or PREPEND.
Then architectures which choose to define CMDLINE_EXTEND in their Kconfigs
can select the generic option that matches their behaviour.

INITRAMFS_FORCE sounds like it should depend on APPEND (assuming that means
CONFIG_CMDLINE is appended to the bootloader arguments).

Christophe