summaryrefslogtreecommitdiffstats
path: root/drivers/mtd/parsers/redboot.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/mtd/parsers/redboot.c')
-rw-r--r--drivers/mtd/parsers/redboot.c323
1 files changed, 323 insertions, 0 deletions
diff --git a/drivers/mtd/parsers/redboot.c b/drivers/mtd/parsers/redboot.c
new file mode 100644
index 000000000..a16b42a88
--- /dev/null
+++ b/drivers/mtd/parsers/redboot.c
@@ -0,0 +1,323 @@
+// 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");
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-04 20:44:02 +0000