mirror of
https://github.com/torvalds/linux.git
synced 2024-12-24 20:01:55 +00:00
cf9b111c17
Remove old comments that include the old arch/i386 directory. Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
111 lines
1.9 KiB
C
111 lines
1.9 KiB
C
/* -*- linux-c -*- ------------------------------------------------------- *
|
|
*
|
|
* Copyright (C) 1991, 1992 Linus Torvalds
|
|
* Copyright 2007 rPath, Inc. - All Rights Reserved
|
|
*
|
|
* This file is part of the Linux kernel, and is made available under
|
|
* the terms of the GNU General Public License version 2.
|
|
*
|
|
* ----------------------------------------------------------------------- */
|
|
|
|
/*
|
|
* Very simple screen I/O
|
|
* XXX: Probably should add very simple serial I/O?
|
|
*/
|
|
|
|
#include "boot.h"
|
|
|
|
/*
|
|
* These functions are in .inittext so they can be used to signal
|
|
* error during initialization.
|
|
*/
|
|
|
|
void __attribute__((section(".inittext"))) putchar(int ch)
|
|
{
|
|
unsigned char c = ch;
|
|
|
|
if (c == '\n')
|
|
putchar('\r'); /* \n -> \r\n */
|
|
|
|
/* int $0x10 is known to have bugs involving touching registers
|
|
it shouldn't. Be extra conservative... */
|
|
asm volatile("pushal; pushw %%ds; int $0x10; popw %%ds; popal"
|
|
: : "b" (0x0007), "c" (0x0001), "a" (0x0e00|ch));
|
|
}
|
|
|
|
void __attribute__((section(".inittext"))) puts(const char *str)
|
|
{
|
|
int n = 0;
|
|
while (*str) {
|
|
putchar(*str++);
|
|
n++;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Read the CMOS clock through the BIOS, and return the
|
|
* seconds in BCD.
|
|
*/
|
|
|
|
static u8 gettime(void)
|
|
{
|
|
u16 ax = 0x0200;
|
|
u16 cx, dx;
|
|
|
|
asm volatile("int $0x1a"
|
|
: "+a" (ax), "=c" (cx), "=d" (dx)
|
|
: : "ebx", "esi", "edi");
|
|
|
|
return dx >> 8;
|
|
}
|
|
|
|
/*
|
|
* Read from the keyboard
|
|
*/
|
|
int getchar(void)
|
|
{
|
|
u16 ax = 0;
|
|
asm volatile("int $0x16" : "+a" (ax));
|
|
|
|
return ax & 0xff;
|
|
}
|
|
|
|
static int kbd_pending(void)
|
|
{
|
|
u8 pending;
|
|
asm volatile("int $0x16; setnz %0"
|
|
: "=rm" (pending)
|
|
: "a" (0x0100));
|
|
return pending;
|
|
}
|
|
|
|
void kbd_flush(void)
|
|
{
|
|
for (;;) {
|
|
if (!kbd_pending())
|
|
break;
|
|
getchar();
|
|
}
|
|
}
|
|
|
|
int getchar_timeout(void)
|
|
{
|
|
int cnt = 30;
|
|
int t0, t1;
|
|
|
|
t0 = gettime();
|
|
|
|
while (cnt) {
|
|
if (kbd_pending())
|
|
return getchar();
|
|
|
|
t1 = gettime();
|
|
if (t0 != t1) {
|
|
cnt--;
|
|
t0 = t1;
|
|
}
|
|
}
|
|
|
|
return 0; /* Timeout! */
|
|
}
|