It should be independent, the Linux x86 microcode code ( https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/x86/kernel/cpu/microcode/i

It should be independent, the Linux x86 microcode code ( https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/x86/kernel/cpu/microcode/intel.c https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/lin... and /amd.c) seems to write to MSR (model-specific register) 0x79 on Intel and MSR 0xc0010020 on AMD.