cpuid.s:

.global cpuid_vendor

cpuid_vendor:
    pushal

    mov $0x0, %eax
    cpuid

    movl %ebx, (%edi)
    movl %edx, 4(%edi)
    movl %ecx, 8(%edi)

    popal
    ret

source/cpuid.h:

extern void cpuid_vendor(uint8_t cpuid_vendor_string[12]);

kernel.c:

	uint8_t cpuid_vendor_string[12];
    cpuid_vendor(cpuid_vendor_string);

    for (int i = 0; i < 12; i++)
    {
        printf("%c", cpuid_vendor_string[i]);
    }