How to change kernel parameter with GRUB2?

Question

This is not a duplicate. I want to change the following kernel parameters which I find in the default Linux kernel of Ubuntu 16.04LTS/32 4.4.0-59-generic:

CONFIG_MODULE_SIG=y
CONFIG_MODULE_SIG_ALL=y
CONFIG_MODULE_SIG_UEFI=y
CONFIG_MODULES_USE_ELF_REL=y

Of course I can recompile the kernel but I want to avoid it for several reasons. Can I change temporally or permanently grub like this:

GRUB_CMDLINE_LINUX=" … CONFIG_MODULE_SIG=n CONFIG_MODULE_SIG_ALL=n CONFIG_MODULE_SIG_UEFI=n CONFIG_MODULES_USE_ELF_REL=n"

Is this the correct way to do so or has this no effect on the kernel parameters?

Answer 1

You are confusing "kernel boot parameters" with "kernel configuration parameters". To do what you want, even though you don't want to, you need to modify the kernel configuration file and re-compile the kernel.

Because they are compile time directives, it is not possible to change kernel configuration parameters via the grub command line. However, and depending on what they are, sometimes the users objectives can still be achieved via kernel command line in grub. For example, say my kernel configuration had CONFIG_X86_INTEL_PSTATE=y. I can still tell the kernel not to use the Intel P-state CPU frequency scaling driver via this:

GRUB_CMDLINE_LINUX_DEFAULT="intel_pstate=disable"

in grub. So even though it is compiled into the kernel, it will not be used.