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#include <system.h>

   int gdt_install();
   int idt_install();
   int isrs_install();
   int irq_install();
   int init_video();
   float timer_install();
   float keyboard_install();

/* copys 'count' bytes'bytes of data from 'src' to
   *  'dest', finally return 'dest' */
void *memcpy(void *dest, const void *src, size_t count)
{
    const char *sp = (const char *)src;
    char *dp = (char *)dest;
    for(; count != 0; count--) *dp++ = *sp++;
    return dest;
}

/*  sets 'count' bytes in 'dest' to 'val'.
    *  Again, return 'dest' */
void *memset(void *dest, char val, size_t count)
{
    char *temp = (char *)dest;
    for( ; count != 0; count--) *temp++ = val;
    return dest;
}
/* Same as above, but this time, we're working with a 16-bit
    *  'val' and dest pointer. Your code can be an exact copy of
    *  the above, provided that your local variables if any, are
    *  unsigned short */
unsigned short *memsetw(unsigned short *dest, unsigned short val, size_t count)
{
    unsigned short *temp = (unsigned short *)dest;
    for( ; count != 0; count--) *temp++ = val;
    return dest;
}
/* This loops through character array 'str', returning how
    *  many characters it needs to check before it finds a 0.
    *  In simple words, it returns the length in bytes of a string */
size_t strlen(const char *str)
{
    size_t retval;
    for(retval = 0; *str != '\0'; str++) retval++;
    return retval;
}
//reads I/O ports
unsigned char inportb (unsigned short _port)
{
    unsigned char rv;
    __asm__ __volatile__ ("inb %1, %0" : "=a" (rv) : "dN" (_port));
    return rv;
}
//writes I/O ports
void outportb (unsigned short _port, unsigned char _data)
{
    __asm__ __volatile__ ("outb %1, %0" : : "dN" (_port), "a" (_data));
}
//simple main function
void main()
{
    int i;

    gdt_install();
    idt_install();
    isrs_install();
    irq_install();
    init_video();
    timer_install();
    keyboard_install();

    __asm__ __volatile__ ("sti");

    puts("test\n");

//    i = 10 / 0;
//    putch(i);

    for (;;);
}

#ifndef __SYSTEM_H
#define __SYSTEM_H

/* MAIN.C */
extern unsigned char *memcpy(unsigned char *dest, const unsigned char *src, int count);
extern unsigned char *memset(unsigned char *dest, unsigned char val, int count);
extern unsigned short *memsetw(unsigned short *dest, unsigned short val, int count);
extern int strlen(const char *str);
extern unsigned char inportb (unsigned short _port);
extern void outportb (unsigned short _port, unsigned char _data);

#endif

  int gdt_install();
  int idt_install();
  int isrs_install();
  int irq_install();
  int init_video();
  float timer_install();
  float keyboard_install();

extern unsigned char *memcpy(unsigned char *dest, const unsigned char *src, int count);
extern unsigned char *memset(unsigned char *dest, unsigned char val, int count);
extern unsigned short *memsetw(unsigned short *dest, unsigned short val, int count);
extern int strlen(const char *str);

size_t retval;