serial.c

来自「newos is new operation system」· C语言 代码 · 共 47 行

#include "of.h"
#include "isa.h"

#define SERIAL_REG(x) (*(volatile unsigned char *)(0xfe000000 | (x)))

int init_serial(void)
{
	isa_write8(0x2fb, 0x80);
	isa_write8(0x2f8, 1);
	isa_write8(0x2f9, 0);
	isa_write8(0x2fb, 0x3);

	return 0;
}

void serial_write(const void *_buf, int len)
{
	const unsigned char *buf = _buf;
	int i;

	for(i=0; i < len; i++) {
		while ((isa_read8(0x2fd) & 0x20) == 0)
			;
		isa_write8(0x2f8, buf[i]);
	}
}

int serial_read(void *_buf, int len)
{
	unsigned char *buf = _buf;
	int i;

	for(i=0; i < len; i++) {
		while ((isa_read8(0x2fd) & 1) == 0)
			;
		buf[i] = isa_read8(0x2f8);
	}
	return i;
}

int serial_read_int32(int *buf)
{
	if(serial_read(buf, 4) != 4)
		return -1;
	return 0;
}