mtd: Move Redboot partition parser

This moves the Redboot partition parser down to the parsers
subdirectory.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

3 files changed, 353 insertions, 0 deletions

diff --git a/drivers/mtd/parsers/Kconfig b/drivers/mtd/parsers/Kconfig
index ee5ab994132f..fccf1950e92d 100644
--- a/drivers/mtd/parsers/Kconfig
+++ b/drivers/mtd/parsers/Kconfig
@@ -14,3 +14,53 @@ config MTD_SHARPSL_PARTS
 	  This provides the read-only FTL logic necessary to read the partition
 	  table from the NAND flash of Sharp SL Series (Zaurus) and the MTD
 	  partition parser using this code.
+
+config MTD_REDBOOT_PARTS
+	tristate "RedBoot partition table parsing"
+	help
+	  RedBoot is a ROM monitor and bootloader which deals with multiple
+	  'images' in flash devices by putting a table one of the erase
+	  blocks on the device, similar to a partition table, which gives
+	  the offsets, lengths and names of all the images stored in the
+	  flash.
+
+	  If you need code which can detect and parse this table, and register
+	  MTD 'partitions' corresponding to each image in the table, enable
+	  this option.
+
+	  You will still need the parsing functions to be called by the driver
+	  for your particular device. It won't happen automatically. The
+	  SA1100 map driver (CONFIG_MTD_SA1100) has an option for this, for
+	  example.
+
+if MTD_REDBOOT_PARTS
+
+config MTD_REDBOOT_DIRECTORY_BLOCK
+	int "Location of RedBoot partition table"
+	default "-1"
+	help
+	  This option is the Linux counterpart to the
+	  CYGNUM_REDBOOT_FIS_DIRECTORY_BLOCK RedBoot compile time
+	  option.
+
+	  The option specifies which Flash sectors holds the RedBoot
+	  partition table.  A zero or positive value gives an absolute
+	  erase block number. A negative value specifies a number of
+	  sectors before the end of the device.
+
+	  For example "2" means block number 2, "-1" means the last
+	  block and "-2" means the penultimate block.
+
+config MTD_REDBOOT_PARTS_UNALLOCATED
+	bool "Include unallocated flash regions"
+	help
+	  If you need to register each unallocated flash region as a MTD
+	  'partition', enable this option.
+
+config MTD_REDBOOT_PARTS_READONLY
+	bool "Force read-only for RedBoot system images"
+	help
+	  If you need to force read-only for 'RedBoot', 'RedBoot Config' and
+	  'FIS directory' images, enable this option.
+
+endif # MTD_REDBOOT_PARTS
diff --git a/drivers/mtd/parsers/Makefile b/drivers/mtd/parsers/Makefile
index 5b1bcc3d90d9..d8418bf6804a 100644
--- a/drivers/mtd/parsers/Makefile
+++ b/drivers/mtd/parsers/Makefile
@@ -1,2 +1,3 @@
 obj-$(CONFIG_MTD_PARSER_TRX)		+= parser_trx.o
 obj-$(CONFIG_MTD_SHARPSL_PARTS)		+= sharpslpart.o
+obj-$(CONFIG_MTD_REDBOOT_PARTS)		+= redboot.o
diff --git a/drivers/mtd/parsers/redboot.c b/drivers/mtd/parsers/redboot.c
new file mode 100644
index 000000000000..7623ac5fc586
--- /dev/null
+++ b/drivers/mtd/parsers/redboot.c
@@ -0,0 +1,302 @@
+/*
+ * 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>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/vmalloc.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
+    uint32_t	  flash_base;    // Address within FLASH of image
+    uint32_t	  mem_base;      // Address in memory where it executes
+    uint32_t	  size;          // Length of image
+    uint32_t	  entry_point;   // Execution entry point
+    uint32_t	  data_length;   // Length of actual data
+    unsigned char _pad[256-(16+7*sizeof(uint32_t))];
+    uint32_t	  desc_cksum;    // Checksum over image descriptor
+    uint32_t	  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 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
+
+	if ( directory < 0 ) {
+		offset = master->size + directory * master->erasesize;
+		while (mtd_block_isbad(master, offset)) {
+			if (!offset) {
+			nogood:
+				printk(KERN_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;
+
+	printk(KERN_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 */
+		printk(KERN_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 struct mtd_part_parser redboot_parser = {
+	.parse_fn = parse_redboot_partitions,
+	.name = "RedBoot",
+};
+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");