cpuid.c

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#include <type.h>
#include <hal/cpu/cpuid.h>
 
void cpuid(uint32_t leaf, uint32_t subleaf, uint32_t* eax, uint32_t* ebx,
       uint32_t* ecx, uint32_t* edx) {
    uint32_t a, b, c, d;
    asm volatile("cpuid"
             : "=a"(a), "=b"(b), "=c"(c), "=d"(d)
             : "a"(leaf), "c"(subleaf)
             : "memory");
    if (eax)
        *eax = a;
    if (ebx)
        *ebx = b;
    if (ecx)
        *ecx = c;
    if (edx)
        *edx = d;
}
 
int cpuid_get_model(void) {
    uint32_t eax, ebx, ecx, edx;
    cpuid(1, 0, &eax, &ebx, &ecx, &edx);
    int family =
        ((eax >> 8) & 0xf) + ((eax >> 20) & 0xff); // extended family
    int model = (int) (((eax >> 4) & 0xf)
               + (((eax >> 16) & 0xf) << 4)); // extended model
    return model + (family << 8);             // encode family+model
}
 
boolean_t cpuid_check_apic(void) {
    uint32_t eax, ebx, ecx, edx;
    cpuid(1, 0, &eax, &ebx, &ecx, &edx);
    return (edx & (1 << 9)) != 0;
}
 
int cpuid_get_bsp_id(void) {
    uint32_t eax, ebx, ecx, edx;
    cpuid(1, 0, &eax, &ebx, &ecx, &edx);
    return (ebx >> 24) & 0xff;
}