diff options
Diffstat (limited to 'drivers/mtd/parsers/cmdlinepart.c')
| -rw-r--r-- | drivers/mtd/parsers/cmdlinepart.c | 400 |
1 files changed, 400 insertions, 0 deletions
diff --git a/drivers/mtd/parsers/cmdlinepart.c b/drivers/mtd/parsers/cmdlinepart.c new file mode 100644 index 000000000000..c86f2db8c882 --- /dev/null +++ b/drivers/mtd/parsers/cmdlinepart.c @@ -0,0 +1,400 @@ +// 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] + * <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; + + /* 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 */ + 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; + } + + /* 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; + 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; + + mtd_id = s; + + /* fetch <mtd-id> */ + p = strchr(s, ':'); + 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"); |