force boot sector feature

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@616 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
bellard 2004-02-16 21:56:36 +00:00
parent f72b519c86
commit cf98951b82

18
block.c
View File

@ -55,6 +55,9 @@ struct BlockDriverState {
int cow_bitmap_size;
int cow_fd;
int64_t cow_sectors_offset;
int boot_sector_enabled;
uint8_t boot_sector_data[512];
char filename[1024];
};
@ -262,6 +265,10 @@ int bdrv_read(BlockDriverState *bs, int64_t sector_num,
if (is_changed(bs->cow_bitmap, sector_num, nb_sectors, &n)) {
fd = bs->cow_fd;
offset = bs->cow_sectors_offset;
} else if (sector_num == 0 && bs->boot_sector_enabled) {
memcpy(buf, bs->boot_sector_data, 512);
n = 1;
goto next;
} else {
fd = bs->fd;
offset = 0;
@ -278,6 +285,7 @@ int bdrv_read(BlockDriverState *bs, int64_t sector_num,
return -1;
}
}
next:
nb_sectors -= n;
sector_num += n;
buf += n * 512;
@ -324,3 +332,13 @@ void bdrv_get_geometry(BlockDriverState *bs, int64_t *nb_sectors_ptr)
{
*nb_sectors_ptr = bs->total_sectors;
}
/* force a given boot sector. */
void bdrv_set_boot_sector(BlockDriverState *bs, const uint8_t *data, int size)
{
bs->boot_sector_enabled = 1;
if (size > 512)
size = 512;
memcpy(bs->boot_sector_data, data, size);
memset(bs->boot_sector_data + size, 0, 512 - size);
}