diff --git a/cmd/Kconfig b/cmd/Kconfig index da86a940ce..0107c0fa3e 100644 --- a/cmd/Kconfig +++ b/cmd/Kconfig @@ -1034,6 +1034,14 @@ config CMD_LSBLK Print list of available block device drivers, and for each, the list of known block devices. +config CMD_MBR + bool "MBR (Master Boot Record) command" + select DOS_PARTITION + select HAVE_BLOCK_DEVICE + help + Enable the 'mbr' command to ready and write MBR (Master Boot Record) + style partition tables. + config CMD_MISC bool "misc" depends on MISC diff --git a/cmd/Makefile b/cmd/Makefile index 5b3400a840..87aa949e2f 100644 --- a/cmd/Makefile +++ b/cmd/Makefile @@ -178,6 +178,7 @@ obj-$(CONFIG_CMD_ZFS) += zfs.o obj-$(CONFIG_CMD_DFU) += dfu.o obj-$(CONFIG_CMD_GPT) += gpt.o +obj-$(CONFIG_CMD_MBR) += mbr.o obj-$(CONFIG_CMD_ETHSW) += ethsw.o obj-$(CONFIG_CMD_AXI) += axi.o obj-$(CONFIG_CMD_PVBLOCK) += pvblock.o diff --git a/cmd/mbr.c b/cmd/mbr.c new file mode 100644 index 0000000000..da2e3a4722 --- /dev/null +++ b/cmd/mbr.c @@ -0,0 +1,314 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * cmd_mbr.c -- MBR (Master Boot Record) handling command + * + * Copyright (C) 2020 Samsung Electronics + * author: Marek Szyprowski + * + * based on the gpt command. + */ + +#include +#include +#include +#include +#include + +/** + * extract_val() - Extract a value from the key=value pair list + * @str: pointer to string with key=values pairs + * @key: pointer to the key to search for + * + * The list of parameters is come separated, only a value for + * the given key is returend. + * + * Function allocates memory for the value, remember to free! + * + * Return: Pointer to allocated string with the value. + */ +static char *extract_val(const char *str, const char *key) +{ + char *v, *k; + char *s, *strcopy; + char *new = NULL; + + strcopy = strdup(str); + if (strcopy == NULL) + return NULL; + + s = strcopy; + while (s) { + v = strsep(&s, ","); + if (!v) + break; + k = strsep(&v, "="); + if (!k) + break; + if (strcmp(k, key) == 0) { + new = strdup(v); + break; + } + } + + free(strcopy); + + return new; +} + +/** + * found_key() - Search for a key without a value in the parameter list + * @str: pointer to string with key + * @key: pointer to the key to search for + * + * The list of parameters is come separated. + * + * Return: True if key has been found. + */ +static bool found_key(const char *str, const char *key) +{ + char *k; + char *s, *strcopy; + bool result = false; + + strcopy = strdup(str); + if (!strcopy) + return NULL; + + s = strcopy; + while (s) { + k = strsep(&s, ","); + if (!k) + break; + if (strcmp(k, key) == 0) { + result = true; + break; + } + } + + free(strcopy); + + return result; +} + +static int str_to_partitions(const char *str_part, int blksz, + unsigned long *disk_uuid, struct disk_partition **partitions, + int *parts_count) +{ + char *tok, *str, *s; + int i; + char *val, *p; + int p_count; + struct disk_partition *parts; + int errno = 0; + uint64_t size_ll, start_ll; + + if (str_part == NULL) + return -1; + + str = strdup(str_part); + if (str == NULL) + return -ENOMEM; + + /* extract disk guid */ + s = str; + val = extract_val(str, "uuid_disk"); + if (val) { + val = strsep(&val, ";"); + p = val; + *disk_uuid = ustrtoull(p, &p, 0); + free(val); + /* Move s to first partition */ + strsep(&s, ";"); + } + if (s == NULL) { + printf("Error: is the partitions string NULL-terminated?\n"); + return -EINVAL; + } + + /* remove the optional semicolon at the end of the string */ + i = strlen(s) - 1; + if (s[i] == ';') + s[i] = '\0'; + + /* calculate expected number of partitions */ + p_count = 1; + p = s; + while (*p) { + if (*p++ == ';') + p_count++; + } + + /* allocate memory for partitions */ + parts = calloc(sizeof(struct disk_partition), p_count); + if (parts == NULL) + return -ENOMEM; + + /* retrieve partitions data from string */ + for (i = 0; i < p_count; i++) { + tok = strsep(&s, ";"); + + if (tok == NULL) + break; + + /* size */ + val = extract_val(tok, "size"); + if (!val) { /* 'size' is mandatory */ + errno = -4; + goto err; + } + p = val; + if ((strcmp(p, "-") == 0)) { + /* auto extend the size */ + parts[i].size = 0; + } else { + size_ll = ustrtoull(p, &p, 0); + parts[i].size = size_ll / blksz; + } + free(val); + + /* start address */ + val = extract_val(tok, "start"); + if (val) { /* start address is optional */ + p = val; + start_ll = ustrtoull(p, &p, 0); + parts[i].start = start_ll / blksz; + free(val); + } + + /* system id */ + val = extract_val(tok, "id"); + if (!val) { /* '' is mandatory */ + errno = -4; + goto err; + } + p = val; + parts[i].sys_ind = ustrtoul(p, &p, 0); + free(val); + + /* bootable */ + if (found_key(tok, "bootable")) + parts[i].bootable = PART_BOOTABLE; + } + + *parts_count = p_count; + *partitions = parts; + free(str); + + return 0; +err: + free(str); + free(parts); + + return errno; +} + +static int do_write_mbr(struct blk_desc *dev, const char *str) +{ + unsigned long disk_uuid = 0; + struct disk_partition *partitions; + int blksz = dev->blksz; + int count; + + if (str_to_partitions(str, blksz, &disk_uuid, &partitions, &count)) { + printf("MBR: failed to setup partitions from \"%s\"\n", str); + return -1; + } + + if (layout_mbr_partitions(partitions, count, dev->lba)) { + printf("MBR: failed to layout partitions on the device\n"); + free(partitions); + return -1; + } + + if (write_mbr_partitions(dev, partitions, count, disk_uuid)) { + printf("MBR: failed to write partitions to the device\n"); + free(partitions); + return -1; + } + + return 0; +} + +static int do_verify_mbr(struct blk_desc *dev, const char *str) +{ + unsigned long disk_uuid = 0; + struct disk_partition *partitions; + int blksz = dev->blksz; + int count, i, ret = 1; + + if (str_to_partitions(str, blksz, &disk_uuid, &partitions, &count)) { + printf("MBR: failed to setup partitions from \"%s\"\n", str); + return -1; + } + + for (i = 0; i < count; i++) { + struct disk_partition p; + + if (part_get_info(dev, i+1, &p)) + goto fail; + + if ((partitions[i].size && p.size < partitions[i].size) || + (partitions[i].start && p.start < partitions[i].start) || + (p.sys_ind != partitions[i].sys_ind)) + goto fail; + } + ret = 0; +fail: + free(partitions); + return ret; +} + +static int do_mbr(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]) +{ + const char *parts = NULL; + int ret = CMD_RET_SUCCESS; + int dev = 0; + char *ep; + struct blk_desc *blk_dev_desc = NULL; + + if (argc != 4 && argc != 5) + return CMD_RET_USAGE; + + dev = (int)simple_strtoul(argv[3], &ep, 10); + if (!ep || ep[0] != '\0') { + printf("'%s' is not a number\n", argv[3]); + return CMD_RET_USAGE; + } + blk_dev_desc = blk_get_dev(argv[2], dev); + if (!blk_dev_desc) { + printf("%s: %s dev %d NOT available\n", + __func__, argv[2], dev); + return CMD_RET_FAILURE; + } + + if ((strcmp(argv[1], "write") == 0)) { + parts = (argc == 5) ? argv[4] : env_get("mbr_parts"); + printf("MBR: write "); + ret = do_write_mbr(blk_dev_desc, parts); + } else if ((strcmp(argv[1], "verify") == 0)) { + printf("MBR: verify "); + parts = (argc == 5) ? argv[4] : env_get("mbr_parts"); + ret = do_verify_mbr(blk_dev_desc, parts); + } else { + return CMD_RET_USAGE; + } + + if (ret) { + printf("error!\n"); + return CMD_RET_FAILURE; + } + + printf("success!\n"); + return CMD_RET_SUCCESS; +} + +U_BOOT_CMD(mbr, CONFIG_SYS_MAXARGS, 1, do_mbr, + "MBR (Master Boot Record)", + " \n" + " - MBR partition table restoration utility\n" + " Restore or check partition information on a device connected\n" + " to the given block interface\n" + " Example usage:\n" + " mbr write mmc 0 [\"${mbr_parts}\"]\n" + " mbr verify mmc 0 [\"${partitions}\"]\n" +); diff --git a/doc/usage/index.rst b/doc/usage/index.rst index fbb2c0481c..5869fba189 100644 --- a/doc/usage/index.rst +++ b/doc/usage/index.rst @@ -14,4 +14,5 @@ Shell commands bootefi bootmenu button + mbr pstore diff --git a/doc/usage/mbr.rst b/doc/usage/mbr.rst new file mode 100644 index 0000000000..bddf2f612a --- /dev/null +++ b/doc/usage/mbr.rst @@ -0,0 +1,94 @@ +.. SPDX-License-Identifier: GPL-2.0+ + +mbr command +=========== + +Synopsis +-------- + +:: + + mbr verify [interface] [device no] [partition list] + mbr write [interface] [device no] [partition list] + +Description +----------- + +The mbr command lets users create or verify the MBR (Master Boot Record) +partition layout based on the provided text description. The partition +layout is alternatively read from the 'mbr_parts' environment variable. +This can be used in scripts to help system image flashing tools to ensure +proper partition layout. + +The syntax of the text description of the partition list is similar to +the one used by the 'gpt' command. + +Supported partition parameters are: + +* name (currently ignored) +* start (partition start offset in bytes) +* size (in bytes or '-' to expand it to the whole free area) +* bootable (boolean flag) +* id (MBR partition type) + +If one wants to create more than 4 partitions, an 'Extended' primary +partition (with 0x05 ID) has to be explicitly provided as a one of the +first 4 entries. + +Here is an example how to create a 6 partitions (3 on the 'extended +volume'), some of the predefined sizes: + +:: + + => setenv mbr_parts 'name=boot,start=4M,size=128M,bootable,id=0x0e; + name=rootfs,size=3072M,id=0x83; + name=system-data,size=512M,id=0x83; + name=[ext],size=-,id=0x05; + name=user,size=-,id=0x83; + name=modules,size=100M,id=0x83; + name=ramdisk,size=8M,id=0x83' + => mbr write mmc 0 + +To check if the layout on the MMC #0 storage device matches the provided +text description one has to issue following command (assuming that +mbr_parts environment variable is set): + +:: + + => mbr verify mmc 0 + +The verify sub-command is especially useful in the system update scripts: + +:: + + => if mbr verify mmc 0; then + echo MBR layout needs to be updated + ... + fi + +The 'mbr write' command returns 0 on success write or 1 on failure. + +The 'mbr verify' returns 0 if the layout matches the one on the storage +device or 1 if not. + +Configuration +------------- + +To use the mbr command you must specify CONFIG_CMD_MBR=y. + +Return value +------------ + +The variable *$?* takes the following values + ++---+------------------------------+ +| 0 | mbr write was succesful | ++---+------------------------------+ +| 1 | mbr write failed | ++---+------------------------------+ +| 0 | mbr verify was succesful | ++---+------------------------------+ +| 1 | mbr verify was not succesful | ++---+------------------------------+ +|-1 | invalid arguments | ++---+------------------------------+