diff options
| -rw-r--r-- | block.c | 20 |
1 files changed, 19 insertions, 1 deletions
@@ -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; @@ -291,7 +299,7 @@ int bdrv_write(BlockDriverState *bs, int64_t sector_num, { int ret, fd, i; int64_t offset, retl; - + if (bs->read_only) return -1; @@ -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); +} |