fpu.c

См. документацию.

 
#include "common.h"
#include "io/ports.h"
 
bool fpu_initialized = false;
 
bool fpu_isInitialized() {
    return fpu_initialized;
}
 
void fpu_fldcw(const uint16_t cw) {
    __asm__ volatile("fldcw %0" : : "m"(cw));
}
 
void fpu_init() {
    uint32_t cr4 = 0;
 
    __asm__ volatile ("mov %%cr4, %0":"=r"(cr4));
    cr4 |= 0x200;
    __asm__ volatile("mov %0, %%cr4"::"r"(cr4));
 
    fpu_fldcw(0x37F);
 
    fpu_initialized = true;
 
    qemu_log("FPU init result: %f (should be 0.5)", 1.0 / 2.0);
}