Support adding kernel commandline options

[jandubois]

Description

#827 added a mechanism to specify additional kernel parameters for a specific image.

Unfortunately this does not allow providing additional parameters via an override.yaml or default.yaml file because image lists are simply concatenated; there is no way to modify attributes of an existing entry like we do for mounts and networks. There is also no obvious way how this can be made to work for images.

I would like to add a top-level attribute cmdline that will be appended in addition to any cmdline setting specified for a particular image. That would allow setting things globally, like:

cmdline: "vsyscall=emulate"

References:
microsoft/WSL#4694
https://gitlab.alpinelinux.org/alpine/aports/-/issues/6927#note_31075

[AkihiroSuda]

Not a huge fan of adding the cmdline as a global attribute.

Wondering if we could rather specify this as an EFI var inside the firmware: section.
I don't know how we could pass the EFI var into the kernel, but I believe it is possible.

[ripun]

Hi Team
is there any update on this ?

[jerindjoy]

Hi Team, Any updates on this or how to enable vsyscall=emulate for Mac running Lima?

[ttc0419]

Really appreciate to have this feature

[ttc0419]

@AkihiroSuda @jandubois There seems two ways we can do it, if we could change the boot loader to LinuxBootLoader we can just use the command line parameter of the function. Otherwise, we could try to use EFI_STUB to boot the kernel, it seems alpine virt kernel is compiled with this option.