// SPDX-License-Identifier: GPL-2.0-or-later /* * Parse RedBoot-style Flash Image System (FIS) tables and * produce a Linux partition array to match. * * Copyright © 2001 Red Hat UK Limited * Copyright © 2001-2010 David Woodhouse <dwmw2@infradead.org> */ #include <linux/kernel.h> #include <linux/slab.h> #include <linux/init.h> #include <linux/vmalloc.h> #include <linux/of.h> #include <linux/mtd/mtd.h> #include <linux/mtd/partitions.h> #include <linux/module.h> struct fis_image_desc { unsigned char name[16]; // Null terminated name u32 flash_base; // Address within FLASH of image u32 mem_base; // Address in memory where it executes u32 size; // Length of image u32 entry_point; // Execution entry point u32 data_length; // Length of actual data unsigned char _pad[256 - (16 + 7 * sizeof(u32))]; u32 desc_cksum; // Checksum over image descriptor u32 file_cksum; // Checksum over image data }; struct fis_list { struct fis_image_desc *img; struct fis_list *next; }; static int directory = CONFIG_MTD_REDBOOT_DIRECTORY_BLOCK; module_param(directory, int, 0); static inline int redboot_checksum(struct fis_image_desc *img) { /* RedBoot doesn't actually write the desc_cksum field yet AFAICT */ return 1; } static void parse_redboot_of(struct mtd_info *master) { struct device_node *np; struct device_node *npart; u32 dirblock; int ret; np = mtd_get_of_node(master); if (!np) return; npart = of_get_child_by_name(np, "partitions"); if (!npart) return; ret = of_property_read_u32(npart, "fis-index-block", &dirblock); of_node_put(npart); if (ret) return; /* * Assign the block found in the device tree to the local * directory block pointer. */ directory = dirblock; } static int parse_redboot_partitions(struct mtd_info *master, const struct mtd_partition **pparts, struct mtd_part_parser_data *data) { int nrparts = 0; struct fis_image_desc *buf; struct mtd_partition *parts; struct fis_list *fl = NULL, *tmp_fl; int ret, i; size_t retlen; char *names; char *nullname; int namelen = 0; int nulllen = 0; int numslots; unsigned long offset; #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED static char nullstring[] = "unallocated"; #endif parse_redboot_of(master); if (directory < 0) { offset = master->size + directory * master->erasesize; while (mtd_block_isbad(master, offset)) { if (!offset) { nogood: pr_notice("Failed to find a non-bad block to check for RedBoot partition table\n"); return -EIO; } offset -= master->erasesize; } } else { offset = directory * master->erasesize; while (mtd_block_isbad(master, offset)) { offset += master->erasesize; if (offset == master->size) goto nogood; } } buf = vmalloc(master->erasesize); if (!buf) return -ENOMEM; pr_notice("Searching for RedBoot partition table in %s at offset 0x%lx\n", master->name, offset); ret = mtd_read(master, offset, master->erasesize, &retlen, (void *)buf); if (ret) goto out; if (retlen != master->erasesize) { ret = -EIO; goto out; } numslots = (master->erasesize / sizeof(struct fis_image_desc)); for (i = 0; i < numslots; i++) { if (!memcmp(buf[i].name, "FIS directory", 14)) { /* This is apparently the FIS directory entry for the * FIS directory itself. The FIS directory size is * one erase block; if the buf[i].size field is * swab32(erasesize) then we know we are looking at * a byte swapped FIS directory - swap all the entries! * (NOTE: this is 'size' not 'data_length'; size is * the full size of the entry.) */ /* RedBoot can combine the FIS directory and config partitions into a single eraseblock; we assume wrong-endian if either the swapped 'size' matches the eraseblock size precisely, or if the swapped size actually fits in an eraseblock while the unswapped size doesn't. */ if (swab32(buf[i].size) == master->erasesize || (buf[i].size > master->erasesize && swab32(buf[i].size) < master->erasesize)) { int j; /* Update numslots based on actual FIS directory size */ numslots = swab32(buf[i].size) / sizeof(struct fis_image_desc); for (j = 0; j < numslots; ++j) { /* A single 0xff denotes a deleted entry. * Two of them in a row is the end of the table. */ if (buf[j].name[0] == 0xff) { if (buf[j].name[1] == 0xff) { break; } else { continue; } } /* The unsigned long fields were written with the * wrong byte sex, name and pad have no byte sex. */ swab32s(&buf[j].flash_base); swab32s(&buf[j].mem_base); swab32s(&buf[j].size); swab32s(&buf[j].entry_point); swab32s(&buf[j].data_length); swab32s(&buf[j].desc_cksum); swab32s(&buf[j].file_cksum); } } else if (buf[i].size < master->erasesize) { /* Update numslots based on actual FIS directory size */ numslots = buf[i].size / sizeof(struct fis_image_desc); } break; } } if (i == numslots) { /* Didn't find it */ pr_notice("No RedBoot partition table detected in %s\n", master->name); ret = 0; goto out; } for (i = 0; i < numslots; i++) { struct fis_list *new_fl, **prev; if (buf[i].name[0] == 0xff) { if (buf[i].name[1] == 0xff) { break; } else { continue; } } if (!redboot_checksum(&buf[i])) break; new_fl = kmalloc(sizeof(struct fis_list), GFP_KERNEL); namelen += strlen(buf[i].name) + 1; if (!new_fl) { ret = -ENOMEM; goto out; } new_fl->img = &buf[i]; if (data && data->origin) buf[i].flash_base -= data->origin; else buf[i].flash_base &= master->size - 1; /* I'm sure the JFFS2 code has done me permanent damage. * I now think the following is _normal_ */ prev = &fl; while (*prev && (*prev)->img->flash_base < new_fl->img->flash_base) prev = &(*prev)->next; new_fl->next = *prev; *prev = new_fl; nrparts++; } #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED if (fl->img->flash_base) { nrparts++; nulllen = sizeof(nullstring); } for (tmp_fl = fl; tmp_fl->next; tmp_fl = tmp_fl->next) { if (tmp_fl->img->flash_base + tmp_fl->img->size + master->erasesize <= tmp_fl->next->img->flash_base) { nrparts++; nulllen = sizeof(nullstring); } } #endif parts = kzalloc(sizeof(*parts) * nrparts + nulllen + namelen, GFP_KERNEL); if (!parts) { ret = -ENOMEM; goto out; } nullname = (char *)&parts[nrparts]; #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED if (nulllen > 0) strcpy(nullname, nullstring); #endif names = nullname + nulllen; i = 0; #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED if (fl->img->flash_base) { parts[0].name = nullname; parts[0].size = fl->img->flash_base; parts[0].offset = 0; i++; } #endif for ( ; i < nrparts; i++) { parts[i].size = fl->img->size; parts[i].offset = fl->img->flash_base; parts[i].name = names; strcpy(names, fl->img->name); #ifdef CONFIG_MTD_REDBOOT_PARTS_READONLY if (!memcmp(names, "RedBoot", 8) || !memcmp(names, "RedBoot config", 15) || !memcmp(names, "FIS directory", 14)) { parts[i].mask_flags = MTD_WRITEABLE; } #endif names += strlen(names) + 1; #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED if (fl->next && fl->img->flash_base + fl->img->size + master->erasesize <= fl->next->img->flash_base) { i++; parts[i].offset = parts[i - 1].size + parts[i - 1].offset; parts[i].size = fl->next->img->flash_base - parts[i].offset; parts[i].name = nullname; } #endif tmp_fl = fl; fl = fl->next; kfree(tmp_fl); } ret = nrparts; *pparts = parts; out: while (fl) { struct fis_list *old = fl; fl = fl->next; kfree(old); } vfree(buf); return ret; } static const struct of_device_id mtd_parser_redboot_of_match_table[] = { { .compatible = "redboot-fis" }, {}, }; MODULE_DEVICE_TABLE(of, mtd_parser_redboot_of_match_table); static struct mtd_part_parser redboot_parser = { .parse_fn = parse_redboot_partitions, .name = "RedBoot", .of_match_table = mtd_parser_redboot_of_match_table, }; module_mtd_part_parser(redboot_parser); /* mtd parsers will request the module by parser name */ MODULE_ALIAS("RedBoot"); MODULE_LICENSE("GPL"); MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); MODULE_DESCRIPTION("Parsing code for RedBoot Flash Image System (FIS) tables");