61 lines
1.3 KiB
C
61 lines
1.3 KiB
C
|
// Fake IDE disk; stores blocks in memory.
|
||
|
|
// Useful for running kernel without scratch disk.
|
||
|
|
|
||
|
|
#include "types.h"
|
||
|
|
#include "defs.h"
|
||
|
|
#include "param.h"
|
||
|
|
#include "mmu.h"
|
||
|
|
#include "proc.h"
|
||
|
|
#include "x86.h"
|
||
|
|
#include "traps.h"
|
||
|
|
#include "spinlock.h"
|
||
|
|
#include "sleeplock.h"
|
||
|
|
#include "fs.h"
|
||
|
|
#include "buf.h"
|
||
|
|
|
||
|
|
extern uchar _binary_fs_img_start[], _binary_fs_img_size[];
|
||
|
|
|
||
|
|
static int disksize;
|
||
|
|
static uchar *memdisk;
|
||
|
|
|
||
|
|
void ideinit(void) {
|
||
|
|
memdisk = _binary_fs_img_start;
|
||
|
|
disksize = (uint)_binary_fs_img_size / BSIZE;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Interrupt handler.
|
||
|
|
void ideintr(void) {
|
||
|
|
// no-op
|
||
|
|
}
|
||
|
|
|
||
|
|
// Sync buf with disk.
|
||
|
|
// If B_DIRTY is set, write buf to disk, clear B_DIRTY, set B_VALID.
|
||
|
|
// Else if B_VALID is not set, read buf from disk, set B_VALID.
|
||
|
|
void iderw(struct buf *b) {
|
||
|
|
uchar *p;
|
||
|
|
|
||
|
|
if (!holdingsleep(&b->lock)) {
|
||
|
|
panic("iderw: buf not locked");
|
||
|
|
}
|
||
|
|
if ((b->flags & (B_VALID | B_DIRTY)) == B_VALID) {
|
||
|
|
panic("iderw: nothing to do");
|
||
|
|
}
|
||
|
|
if (b->dev != 1) {
|
||
|
|
panic("iderw: request not for disk 1");
|
||
|
|
}
|
||
|
|
if (b->blockno >= disksize) {
|
||
|
|
panic("iderw: block out of range");
|
||
|
|
}
|
||
|
|
|
||
|
|
p = memdisk + b->blockno * BSIZE;
|
||
|
|
|
||
|
|
if (b->flags & B_DIRTY) {
|
||
|
|
b->flags &= ~B_DIRTY;
|
||
|
|
memmove(p, b->data, BSIZE);
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
memmove(b->data, p, BSIZE);
|
||
|
|
}
|
||
|
|
b->flags |= B_VALID;
|
||
|
|
}
|