#include <zinnia/errno.h>
#include <uapi/archctl.h>
#include <x86_64/asm.h>
#include <x86_64/defs.h>

errno_t arch_archctl(uintptr_t op, uintptr_t arg) {
    switch (op) {
    case __ARCHCTL_SET_FSBASE:
        asm_wrmsr(MSR_FS_BASE, arg);
        return 0;
    case __ARCHCTL_SET_GSBASE:
        // Update the inactive GSBASE MSR, not ours.
        asm_wrmsr(MSR_KERNEL_GS_BASE, arg);
        return 0;
    default:
        return EINVAL;
    }
}