| Cai Zhiyong | bab5541 | 2013-09-11 14:20:09 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2013 HUAWEI |
| 3 | * Author: Cai Zhiyong <caizhiyong@huawei.com> |
| 4 | * |
| 5 | * Read block device partition table from command line. |
| 6 | * The partition used for fixed block device (eMMC) embedded device. |
| 7 | * It is no MBR, save storage space. Bootloader can be easily accessed |
| 8 | * by absolute address of data on the block device. |
| 9 | * Users can easily change the partition. |
| 10 | * |
| 11 | * The format for the command line is just like mtdparts. |
| 12 | * |
| 13 | * Verbose config please reference "Documentation/block/cmdline-partition.txt" |
| 14 | * |
| 15 | */ |
| 16 | |
| 17 | #include <linux/cmdline-parser.h> |
| 18 | |
| 19 | #include "check.h" |
| 20 | #include "cmdline.h" |
| 21 | |
| 22 | static char *cmdline; |
| 23 | static struct cmdline_parts *bdev_parts; |
| 24 | |
| 25 | static int add_part(int slot, struct cmdline_subpart *subpart, void *param) |
| 26 | { |
| 27 | int label_min; |
| 28 | struct partition_meta_info *info; |
| 29 | char tmp[sizeof(info->volname) + 4]; |
| 30 | struct parsed_partitions *state = (struct parsed_partitions *)param; |
| 31 | |
| 32 | if (slot >= state->limit) |
| 33 | return 1; |
| 34 | |
| 35 | put_partition(state, slot, subpart->from >> 9, |
| 36 | subpart->size >> 9); |
| 37 | |
| 38 | info = &state->parts[slot].info; |
| 39 | |
| 40 | label_min = min_t(int, sizeof(info->volname) - 1, |
| 41 | sizeof(subpart->name)); |
| 42 | strncpy(info->volname, subpart->name, label_min); |
| 43 | info->volname[label_min] = '\0'; |
| 44 | |
| 45 | snprintf(tmp, sizeof(tmp), "(%s)", info->volname); |
| 46 | strlcat(state->pp_buf, tmp, PAGE_SIZE); |
| 47 | |
| 48 | state->parts[slot].has_info = true; |
| 49 | |
| 50 | return 0; |
| 51 | } |
| 52 | |
| 53 | static int __init cmdline_parts_setup(char *s) |
| 54 | { |
| 55 | cmdline = s; |
| 56 | return 1; |
| 57 | } |
| 58 | __setup("blkdevparts=", cmdline_parts_setup); |
| 59 | |
| 60 | /* |
| 61 | * Purpose: allocate cmdline partitions. |
| 62 | * Returns: |
| 63 | * -1 if unable to read the partition table |
| 64 | * 0 if this isn't our partition table |
| 65 | * 1 if successful |
| 66 | */ |
| 67 | int cmdline_partition(struct parsed_partitions *state) |
| 68 | { |
| 69 | sector_t disk_size; |
| 70 | char bdev[BDEVNAME_SIZE]; |
| 71 | struct cmdline_parts *parts; |
| 72 | |
| 73 | if (cmdline) { |
| 74 | if (bdev_parts) |
| 75 | cmdline_parts_free(&bdev_parts); |
| 76 | |
| 77 | if (cmdline_parts_parse(&bdev_parts, cmdline)) { |
| 78 | cmdline = NULL; |
| 79 | return -1; |
| 80 | } |
| 81 | cmdline = NULL; |
| 82 | } |
| 83 | |
| 84 | if (!bdev_parts) |
| 85 | return 0; |
| 86 | |
| 87 | bdevname(state->bdev, bdev); |
| 88 | parts = cmdline_parts_find(bdev_parts, bdev); |
| 89 | if (!parts) |
| 90 | return 0; |
| 91 | |
| 92 | disk_size = get_capacity(state->bdev->bd_disk) << 9; |
| 93 | |
| 94 | cmdline_parts_set(parts, disk_size, 1, add_part, (void *)state); |
| 95 | |
| 96 | strlcat(state->pp_buf, "\n", PAGE_SIZE); |
| 97 | |
| 98 | return 1; |
| 99 | } |