| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * Read flash partition table from command line |
| * |
| * Copyright © 2002 SYSGO Real-Time Solutions GmbH |
| * Copyright © 2002-2010 David Woodhouse <dwmw2@infradead.org> |
| * |
| * The format for the command line is as follows: |
| * |
| * mtdparts=<mtddef>[;<mtddef] |
| * <mtddef> := <mtd-id>:<partdef>[,<partdef>] |
| * <partdef> := <size>[@<offset>][<name>][ro][lk][slc] |
| * <mtd-id> := unique name used in mapping driver/device (mtd->name) |
| * <size> := standard linux memsize OR "-" to denote all remaining space |
| * size is automatically truncated at end of device |
| * if specified or truncated size is 0 the part is skipped |
| * <offset> := standard linux memsize |
| * if omitted the part will immediately follow the previous part |
| * or 0 if the first part |
| * <name> := '(' NAME ')' |
| * NAME will appear in /proc/mtd |
| * |
| * <size> and <offset> can be specified such that the parts are out of order |
| * in physical memory and may even overlap. |
| * |
| * The parts are assigned MTD numbers in the order they are specified in the |
| * command line regardless of their order in physical memory. |
| * |
| * Examples: |
| * |
| * 1 NOR Flash, with 1 single writable partition: |
| * edb7312-nor:- |
| * |
| * 1 NOR Flash with 2 partitions, 1 NAND with one |
| * edb7312-nor:256k(ARMboot)ro,-(root);edb7312-nand:-(home) |
| */ |
| |
| #define pr_fmt(fmt) "mtd: " fmt |
| |
| #include <linux/kernel.h> |
| #include <linux/slab.h> |
| #include <linux/mtd/mtd.h> |
| #include <linux/mtd/partitions.h> |
| #include <linux/module.h> |
| #include <linux/err.h> |
| |
| /* debug macro */ |
| #if 0 |
| #define dbg(x) do { printk("DEBUG-CMDLINE-PART: "); printk x; } while(0) |
| #else |
| #define dbg(x) |
| #endif |
| |
| |
| /* special size referring to all the remaining space in a partition */ |
| #define SIZE_REMAINING ULLONG_MAX |
| #define OFFSET_CONTINUOUS ULLONG_MAX |
| |
| struct cmdline_mtd_partition { |
| struct cmdline_mtd_partition *next; |
| char *mtd_id; |
| int num_parts; |
| struct mtd_partition *parts; |
| }; |
| |
| /* mtdpart_setup() parses into here */ |
| static struct cmdline_mtd_partition *partitions; |
| |
| /* the command line passed to mtdpart_setup() */ |
| static char *mtdparts; |
| static char *cmdline; |
| static int cmdline_parsed; |
| |
| /* |
| * Parse one partition definition for an MTD. Since there can be many |
| * comma separated partition definitions, this function calls itself |
| * recursively until no more partition definitions are found. Nice side |
| * effect: the memory to keep the mtd_partition structs and the names |
| * is allocated upon the last definition being found. At that point the |
| * syntax has been verified ok. |
| */ |
| static struct mtd_partition * newpart(char *s, |
| char **retptr, |
| int *num_parts, |
| int this_part, |
| unsigned char **extra_mem_ptr, |
| int extra_mem_size) |
| { |
| struct mtd_partition *parts; |
| unsigned long long size, offset = OFFSET_CONTINUOUS; |
| char *name; |
| int name_len; |
| unsigned char *extra_mem; |
| char delim; |
| unsigned int mask_flags, add_flags; |
| |
| /* fetch the partition size */ |
| if (*s == '-') { |
| /* assign all remaining space to this partition */ |
| size = SIZE_REMAINING; |
| s++; |
| } else { |
| size = memparse(s, &s); |
| if (!size) { |
| pr_err("partition has size 0\n"); |
| return ERR_PTR(-EINVAL); |
| } |
| } |
| |
| /* fetch partition name and flags */ |
| mask_flags = 0; /* this is going to be a regular partition */ |
| add_flags = 0; |
| delim = 0; |
| |
| /* check for offset */ |
| if (*s == '@') { |
| s++; |
| offset = memparse(s, &s); |
| } |
| |
| /* now look for name */ |
| if (*s == '(') |
| delim = ')'; |
| |
| if (delim) { |
| char *p; |
| |
| name = ++s; |
| p = strchr(name, delim); |
| if (!p) { |
| pr_err("no closing %c found in partition name\n", delim); |
| return ERR_PTR(-EINVAL); |
| } |
| name_len = p - name; |
| s = p + 1; |
| } else { |
| name = NULL; |
| name_len = 13; /* Partition_000 */ |
| } |
| |
| /* record name length for memory allocation later */ |
| extra_mem_size += name_len + 1; |
| |
| /* test for options */ |
| if (strncmp(s, "ro", 2) == 0) { |
| mask_flags |= MTD_WRITEABLE; |
| s += 2; |
| } |
| |
| /* if lk is found do NOT unlock the MTD partition*/ |
| if (strncmp(s, "lk", 2) == 0) { |
| mask_flags |= MTD_POWERUP_LOCK; |
| s += 2; |
| } |
| |
| /* if slc is found use emulated SLC mode on this partition*/ |
| if (!strncmp(s, "slc", 3)) { |
| add_flags |= MTD_SLC_ON_MLC_EMULATION; |
| s += 3; |
| } |
| |
| /* test if more partitions are following */ |
| if (*s == ',') { |
| if (size == SIZE_REMAINING) { |
| pr_err("no partitions allowed after a fill-up partition\n"); |
| return ERR_PTR(-EINVAL); |
| } |
| /* more partitions follow, parse them */ |
| parts = newpart(s + 1, &s, num_parts, this_part + 1, |
| &extra_mem, extra_mem_size); |
| if (IS_ERR(parts)) |
| return parts; |
| } else { |
| /* this is the last partition: allocate space for all */ |
| int alloc_size; |
| |
| *num_parts = this_part + 1; |
| alloc_size = *num_parts * sizeof(struct mtd_partition) + |
| extra_mem_size; |
| |
| parts = kzalloc(alloc_size, GFP_KERNEL); |
| if (!parts) |
| return ERR_PTR(-ENOMEM); |
| extra_mem = (unsigned char *)(parts + *num_parts); |
| } |
| |
| /* |
| * enter this partition (offset will be calculated later if it is |
| * OFFSET_CONTINUOUS at this point) |
| */ |
| parts[this_part].size = size; |
| parts[this_part].offset = offset; |
| parts[this_part].mask_flags = mask_flags; |
| parts[this_part].add_flags = add_flags; |
| if (name) |
| strlcpy(extra_mem, name, name_len + 1); |
| else |
| sprintf(extra_mem, "Partition_%03d", this_part); |
| parts[this_part].name = extra_mem; |
| extra_mem += name_len + 1; |
| |
| dbg(("partition %d: name <%s>, offset %llx, size %llx, mask flags %x\n", |
| this_part, parts[this_part].name, parts[this_part].offset, |
| parts[this_part].size, parts[this_part].mask_flags)); |
| |
| /* return (updated) pointer to extra_mem memory */ |
| if (extra_mem_ptr) |
| *extra_mem_ptr = extra_mem; |
| |
| /* return (updated) pointer command line string */ |
| *retptr = s; |
| |
| /* return partition table */ |
| return parts; |
| } |
| |
| /* |
| * Parse the command line. |
| */ |
| static int mtdpart_setup_real(char *s) |
| { |
| cmdline_parsed = 1; |
| |
| for( ; s != NULL; ) |
| { |
| struct cmdline_mtd_partition *this_mtd; |
| struct mtd_partition *parts; |
| int mtd_id_len, num_parts; |
| char *p, *mtd_id, *semicol; |
| |
| /* |
| * Replace the first ';' by a NULL char so strrchr can work |
| * properly. |
| */ |
| semicol = strchr(s, ';'); |
| if (semicol) |
| *semicol = '\0'; |
| |
| mtd_id = s; |
| |
| /* |
| * fetch <mtd-id>. We use strrchr to ignore all ':' that could |
| * be present in the MTD name, only the last one is interpreted |
| * as an <mtd-id>/<part-definition> separator. |
| */ |
| p = strrchr(s, ':'); |
| |
| /* Restore the ';' now. */ |
| if (semicol) |
| *semicol = ';'; |
| |
| if (!p) { |
| pr_err("no mtd-id\n"); |
| return -EINVAL; |
| } |
| mtd_id_len = p - mtd_id; |
| |
| dbg(("parsing <%s>\n", p+1)); |
| |
| /* |
| * parse one mtd. have it reserve memory for the |
| * struct cmdline_mtd_partition and the mtd-id string. |
| */ |
| parts = newpart(p + 1, /* cmdline */ |
| &s, /* out: updated cmdline ptr */ |
| &num_parts, /* out: number of parts */ |
| 0, /* first partition */ |
| (unsigned char**)&this_mtd, /* out: extra mem */ |
| mtd_id_len + 1 + sizeof(*this_mtd) + |
| sizeof(void*)-1 /*alignment*/); |
| if (IS_ERR(parts)) { |
| /* |
| * An error occurred. We're either: |
| * a) out of memory, or |
| * b) in the middle of the partition spec |
| * Either way, this mtd is hosed and we're |
| * unlikely to succeed in parsing any more |
| */ |
| return PTR_ERR(parts); |
| } |
| |
| /* align this_mtd */ |
| this_mtd = (struct cmdline_mtd_partition *) |
| ALIGN((unsigned long)this_mtd, sizeof(void *)); |
| /* enter results */ |
| this_mtd->parts = parts; |
| this_mtd->num_parts = num_parts; |
| this_mtd->mtd_id = (char*)(this_mtd + 1); |
| strlcpy(this_mtd->mtd_id, mtd_id, mtd_id_len + 1); |
| |
| /* link into chain */ |
| this_mtd->next = partitions; |
| partitions = this_mtd; |
| |
| dbg(("mtdid=<%s> num_parts=<%d>\n", |
| this_mtd->mtd_id, this_mtd->num_parts)); |
| |
| |
| /* EOS - we're done */ |
| if (*s == 0) |
| break; |
| |
| /* does another spec follow? */ |
| if (*s != ';') { |
| pr_err("bad character after partition (%c)\n", *s); |
| return -EINVAL; |
| } |
| s++; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Main function to be called from the MTD mapping driver/device to |
| * obtain the partitioning information. At this point the command line |
| * arguments will actually be parsed and turned to struct mtd_partition |
| * information. It returns partitions for the requested mtd device, or |
| * the first one in the chain if a NULL mtd_id is passed in. |
| */ |
| static int parse_cmdline_partitions(struct mtd_info *master, |
| const struct mtd_partition **pparts, |
| struct mtd_part_parser_data *data) |
| { |
| unsigned long long offset; |
| int i, err; |
| struct cmdline_mtd_partition *part; |
| const char *mtd_id = master->name; |
| |
| /* parse command line */ |
| if (!cmdline_parsed) { |
| err = mtdpart_setup_real(cmdline); |
| if (err) |
| return err; |
| } |
| |
| /* |
| * Search for the partition definition matching master->name. |
| * If master->name is not set, stop at first partition definition. |
| */ |
| for (part = partitions; part; part = part->next) { |
| if ((!mtd_id) || (!strcmp(part->mtd_id, mtd_id))) |
| break; |
| } |
| |
| if (!part) |
| return 0; |
| |
| for (i = 0, offset = 0; i < part->num_parts; i++) { |
| if (part->parts[i].offset == OFFSET_CONTINUOUS) |
| part->parts[i].offset = offset; |
| else |
| offset = part->parts[i].offset; |
| |
| if (part->parts[i].size == SIZE_REMAINING) |
| part->parts[i].size = master->size - offset; |
| |
| if (offset + part->parts[i].size > master->size) { |
| pr_warn("%s: partitioning exceeds flash size, truncating\n", |
| part->mtd_id); |
| part->parts[i].size = master->size - offset; |
| } |
| offset += part->parts[i].size; |
| |
| if (part->parts[i].size == 0) { |
| pr_warn("%s: skipping zero sized partition\n", |
| part->mtd_id); |
| part->num_parts--; |
| memmove(&part->parts[i], &part->parts[i + 1], |
| sizeof(*part->parts) * (part->num_parts - i)); |
| i--; |
| } |
| } |
| |
| *pparts = kmemdup(part->parts, sizeof(*part->parts) * part->num_parts, |
| GFP_KERNEL); |
| if (!*pparts) |
| return -ENOMEM; |
| |
| return part->num_parts; |
| } |
| |
| |
| /* |
| * This is the handler for our kernel parameter, called from |
| * main.c::checksetup(). Note that we can not yet kmalloc() anything, |
| * so we only save the commandline for later processing. |
| * |
| * This function needs to be visible for bootloaders. |
| */ |
| static int __init mtdpart_setup(char *s) |
| { |
| cmdline = s; |
| return 1; |
| } |
| |
| __setup("mtdparts=", mtdpart_setup); |
| |
| static struct mtd_part_parser cmdline_parser = { |
| .parse_fn = parse_cmdline_partitions, |
| .name = "cmdlinepart", |
| }; |
| |
| static int __init cmdline_parser_init(void) |
| { |
| if (mtdparts) |
| mtdpart_setup(mtdparts); |
| register_mtd_parser(&cmdline_parser); |
| return 0; |
| } |
| |
| static void __exit cmdline_parser_exit(void) |
| { |
| deregister_mtd_parser(&cmdline_parser); |
| } |
| |
| module_init(cmdline_parser_init); |
| module_exit(cmdline_parser_exit); |
| |
| MODULE_PARM_DESC(mtdparts, "Partitioning specification"); |
| module_param(mtdparts, charp, 0); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Marius Groeger <mag@sysgo.de>"); |
| MODULE_DESCRIPTION("Command line configuration of MTD partitions"); |