xv6-cs450/ide.c
2006-06-16 20:29:25 +00:00

117 lines
2.1 KiB
C

/*
* Minimal PIO-based (non-interrupt-driven) IDE driver code.
* For information about what all this IDE/ATA magic means,
* see the materials available on the class references page.
*/
#include "types.h"
#include "param.h"
#include "mmu.h"
#include "proc.h"
#include "defs.h"
#include "x86.h"
#define IDE_BSY 0x80
#define IDE_DRDY 0x40
#define IDE_DF 0x20
#define IDE_ERR 0x01
static int diskno = 0;
static int
ide_wait_ready(int check_error)
{
int r;
while (((r = inb(0x1F7)) & (IDE_BSY|IDE_DRDY)) != IDE_DRDY)
/* do nothing */;
if (check_error && (r & (IDE_DF|IDE_ERR)) != 0)
return -1;
return 0;
}
int
ide_probe_disk1(void)
{
int r, x;
// wait for Device 0 to be ready
ide_wait_ready(0);
// switch to Device 1
outb(0x1F6, 0xE0 | (1<<4));
// check for Device 1 to be ready for a while
for (x = 0; x < 1000 && (r = inb(0x1F7)) == 0; x++)
/* do nothing */;
// switch back to Device 0
outb(0x1F6, 0xE0 | (0<<4));
cprintf("Device 1 presence: %d\n", (x < 1000));
return (x < 1000);
}
void
ide_set_disk(int d)
{
if (d != 0 && d != 1)
panic("bad disk number");
diskno = d;
}
int
ide_read(uint32_t secno, void *dst, unsigned nsecs)
{
int r;
if(nsecs > 256)
panic("ide_read");
ide_wait_ready(0);
outb(0x3f6, 0);
outb(0x1F2, nsecs);
outb(0x1F3, secno & 0xFF);
outb(0x1F4, (secno >> 8) & 0xFF);
outb(0x1F5, (secno >> 16) & 0xFF);
outb(0x1F6, 0xE0 | ((diskno&1)<<4) | ((secno>>24)&0x0F));
outb(0x1F7, 0x20); // CMD 0x20 means read sector
sleep(0);
for (; nsecs > 0; nsecs--, dst += 512) {
if ((r = ide_wait_ready(1)) < 0)
return r;
insl(0x1F0, dst, 512/4);
}
return 0;
}
int
ide_write(uint32_t secno, const void *src, unsigned nsecs)
{
int r;
if(nsecs > 256)
panic("ide_write");
ide_wait_ready(0);
outb(0x1F2, nsecs);
outb(0x1F3, secno & 0xFF);
outb(0x1F4, (secno >> 8) & 0xFF);
outb(0x1F5, (secno >> 16) & 0xFF);
outb(0x1F6, 0xE0 | ((diskno&1)<<4) | ((secno>>24)&0x0F));
outb(0x1F7, 0x30); // CMD 0x30 means write sector
for (; nsecs > 0; nsecs--, src += 512) {
if ((r = ide_wait_ready(1)) < 0)
return r;
outsl(0x1F0, src, 512/4);
}
return 0;
}