iolib.c

别人的根据linux0.11改的一个小的操作系统

/*
 * iolib.c
 *
 * There are some user functions,kernel can also...
 */
#include "def.h"
#include "time.h"
#include "sched.h"
#include "stdio.h"
#include "system.h"

void outportb(unsigned short port,unsigned char data)
{
	asm(
		"movw	%0,%%dx;"
		"movb	%1,%%al;"
		"outb	%%al,%%dx;"
		::"r"(port),"r"(data)
		:"%eax","%edx");
}
unsigned char inportb(unsigned short port)
{
	unsigned char data=0;

	asm(
		"movw	%1,%%dx;"
		"inb	%%dx,%%al;"
		"movb	%%al,%0;"
		:"=r"(data)
		:"r"(port)
		:"%eax","%edx");
		
	return data;
}
/*
 *clear screen
 *the function is a system call 0x80->0x01
 */
void clrscr()
{
	asm(
		"pushl	%%eax;"
		"movl	$0x01,%%eax;"
		"int	$0x80;"
		"popl	%%eax;"
		::
		:"%eax");
}
/*
 *scroll screen to up
 *system call 0x80->0x03
 */
void scrup()
{
	asm(
		"pushl	%%eax;"
		"movl	$0x03,%%eax;"
		"int	$0x80;"
		"popl	%%eax;"
		::
		:"%eax");
}



void print(char *str)
{
	while(*str){

		if(*str=='\n'){
			setCursor(0,getCursorRow()+1);
			str++;
			continue;
		}

		putchar(*str);
		str++;
	}
}

void memcopy(char *dest,char *source,long nbytes)
{
    while(nbytes--)
    {
        *(dest++) = *(source++);
    }
}