Append options to GRUB_CMDLINE_LINUX_DEFAULT without modification on files

Question

I want to add an option to GRUB_CMDLINE_LINUX_DEFAULT without modifying any files on the system. The reason is that I want to apply it by installing a driver package, but currently I haven't found any way to do that without touching /etc/default/grub or /etc/grub/10_linux. I tried to add it with the script below which should be executed before 10_linux but it has no effect:

$ cat /etc/grub.d/09_linux_vmalloc 
    #!/bin/sh
    set -e

    export GRUB_CMDLINE_LINUX_DEFAULT="$GRUB_CMDLINE_LINUX_DEFAULT vmalloc=256MB"

Solution

Newer grub packages now provide to add files with own modifications at /etc/default/grub.d/ . In my case I was able to modify grub with my packaging by:

thopiekar@t91:~$ cat /etc/default/grub.d/emgd.cfg 
GRUB_CMDLINE_LINUX_DEFAULT="$GRUB_CMDLINE_LINUX_DEFAULT vmalloc=256MB selinux=0 vga=current"

Thank you all anyway :)

Comments

[bain]

It is not really clear what exactly you are trying to do, or why, but you can edit /boot/grub/grub.cfg directly without editing /etc files, or you can run grub-mkconfig and then modify the output.

[Eliah Kagan]

@bain I'd suggest posting that (or something like it) as an answer.

[thopiekar]

Well, that'S not what I want to do. I just want to provide a file (placed somewhere) to make update-grub append my needed option without changing any (upstream) files. I already done that years before using a script, but it broke (somehow) others /etc/default/grub . Just want to avoid that...

[muru]

How new? Which Ubuntu version started supporting this?

[thopiekar]

Don't know. Just found it after installing linux-crashdump to debug a kernel module. kexec is using to to pass parameters to grub.