#define FOOLOS_MODULE_NAME "x86"

#include "x86.h"
#include "timer.h"
#include "lib/logger/log.h"

//
// suffix (b, w, l, q for byte, word, dword, and qword).
//


/*
volatile void sleep(int i)
{
    uint64_t clock=timer_get_ticks();
    while(clock+i>timer_get_ticks());
}
*/


// disable interrupts
void x86_int_disable()
{
    asm volatile("cli");
}

// enable interrupts
void x86_int_enable()
{
    asm volatile("sti");
}

// get control registers (cr0-cr4)
uint32_t x86_get_cr0()
{
    uint32_t cr;
    asm volatile("mov %%cr0, %0": "=b"(cr));
    return cr;
}

uint32_t x86_get_cr1()
{
    uint32_t cr=0;
    
    // reading the reserved cr1 register results in crash.
    // (at least on emulators)
    // asm volatile("mov %%cr1, %0": "=b"(cr));
    
    return cr;
}

void x86_mov(uint8_t val)
{
}

uint32_t x86_get_cr2()
{
    uint32_t cr;
    asm volatile("mov %%cr2, %0": "=b"(cr));
    return cr;
}

uint32_t x86_get_cr3()
{
    uint32_t cr=0;
    asm volatile("mov %%cr3, %0": "=b"(cr));
    return cr;
}

uint32_t x86_get_cr4()
{
    uint32_t cr;
    asm volatile("mov %%cr4, %0": "=b"(cr));
    return cr;
}
void x86_outb(int port, uint8_t data)
{
    asm volatile("outb %0,%w1" : : "a" (data), "d" (port));
}

uint8_t x86_inb(int port)
{
    uint8_t data;
    asm volatile("inb %w1,%0" : "=a" (data) : "d" (port));
    return data;
}

void x86_outw(int port, uint16_t data)
{
    asm volatile("outw %0,%w1" : : "a" (data), "d" (port));
}

uint16_t x86_inw(int port)
{
    uint16_t data;
    asm volatile("inw %w1,%0" : "=a" (data) : "d" (port));
    return data;
}

void x86_outl(int port, uint32_t data)
{
    asm volatile("outl %0,%w1" : : "a" (data), "d" (port));
}

uint32_t x86_inl(int port)
{
    uint32_t data;
    asm volatile("inl %w1,%0" : "=a" (data) : "d" (port));
    return data;
}


void x86_set_pdbr(uint32_t addr) 
{
    asm volatile("mov %0, %%cr3":: "b"(addr));

}

// enable PT bit in CR0
void x86_paging_enable()
{
    uint32_t cr0=x86_get_cr0();
    cr0 |= 0x80000000; // enable paging 
    asm volatile("mov %0, %%cr0":: "b"(cr0));
}


// disable PT bit in CR0
void x86_paging_disable()
{
    uint32_t cr0=x86_get_cr0();
    cr0 &= ~0x80000000;
    asm volatile("mov %0, %%cr0":: "b"(cr0));
}

void x86_flush_tlb(uint32_t addr)
{
    asm volatile("invlpg (%0)" ::"r" (addr) : "memory");
}

//xchg
uint8_t x86_xchg(uint8_t *addr, uint8_t val)
{   

  uint8_t result;

  // The + in "+m" denotes a read-modify-write operand.
  asm volatile("lock xchgb %0, %1" :
               "+m" (*addr), "=a" (result) :
               "1" (val) :
               "cc");

 //log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"xchg val:%d with addr:0x%08X : result: %d",val,addr,result);
 
  return result;
}