/* * Copyright (C) 2013 HUAWEI * Author: Cai Zhiyong <caizhiyong@huawei.com> * * Read block device partition table from the command line. * Typically used for fixed block (eMMC) embedded devices. * It has no MBR, so saves storage space. Bootloader can be easily accessed * by absolute address of data on the block device. * Users can easily change the partition. * * The format for the command line is just like mtdparts. * * For further information, see "Documentation/block/cmdline-partition.txt" * */ #include <linux/cmdline-parser.h> #include "check.h" #include "cmdline.h" static char *cmdline; static struct cmdline_parts *bdev_parts; static int add_part(int slot, struct cmdline_subpart *subpart, void *param) { int label_min; struct partition_meta_info *info; char tmp[sizeof(info->volname) + 4]; struct parsed_partitions *state = (struct parsed_partitions *)param; if (slot >= state->limit) return 1; put_partition(state, slot, subpart->from >> 9, subpart->size >> 9); info = &state->parts[slot].info; label_min = min_t(int, sizeof(info->volname) - 1, sizeof(subpart->name)); strncpy(info->volname, subpart->name, label_min); info->volname[label_min] = '\0'; snprintf(tmp, sizeof(tmp), "(%s)", info->volname); strlcat(state->pp_buf, tmp, PAGE_SIZE); state->parts[slot].has_info = true; return 0; } static int __init cmdline_parts_setup(char *s) { cmdline = s; return 1; } __setup("blkdevparts=", cmdline_parts_setup); /* * Purpose: allocate cmdline partitions. * Returns: * -1 if unable to read the partition table * 0 if this isn't our partition table * 1 if successful */ int cmdline_partition(struct parsed_partitions *state) { sector_t disk_size; char bdev[BDEVNAME_SIZE]; struct cmdline_parts *parts; if (cmdline) { if (bdev_parts) cmdline_parts_free(&bdev_parts); if (cmdline_parts_parse(&bdev_parts, cmdline)) { cmdline = NULL; return -1; } cmdline = NULL; } if (!bdev_parts) return 0; bdevname(state->bdev, bdev); parts = cmdline_parts_find(bdev_parts, bdev); if (!parts) return 0; disk_size = get_capacity(state->bdev->bd_disk) << 9; cmdline_parts_set(parts, disk_size, 1, add_part, (void *)state); strlcat(state->pp_buf, "\n", PAGE_SIZE); return 1; }