UBI - Unsorted Block Images

UBI (Latin: "where?") manages multiple logical volumes on a single
flash device, specifically supporting NAND flash devices. UBI provides
a flexible partitioning concept which still allows for wear-levelling
across the whole flash device.

In a sense, UBI may be compared to the Logical Volume Manager
(LVM). Whereas LVM maps logical sector numbers to physical HDD sector
numbers, UBI maps logical eraseblocks to physical eraseblocks.

More information may be found in the UBI design documentation:
ubidesign.pdf. Which can be found here:
http://www.linux-mtd.infradead.org/doc/ubi.html

Partitioning/Re-partitioning

  An UBI volume occupies a certain number of erase blocks. This is
  limited by a configured maximum volume size, which could also be
  viewed as the partition size. Each individual UBI volume's size can
  be changed independently of the other UBI volumes, provided that the
  sum of all volume sizes doesn't exceed a certain limit.

  UBI supports dynamic volumes and static volumes. Static volumes are
  read-only and their contents are protected by CRC check sums.

Bad eraseblocks handling

  UBI transparently handles bad eraseblocks. When a physical
  eraseblock becomes bad, it is substituted by a good physical
  eraseblock, and the user does not even notice this.

Scrubbing

  On a NAND flash bit flips can occur on any write operation,
  sometimes also on read. If bit flips persist on the device, at first
  they can still be corrected by ECC, but once they accumulate,
  correction will become impossible. Thus it is best to actively scrub
  the affected eraseblock, by first copying it to a free eraseblock
  and then erasing the original. The UBI layer performs this type of
  scrubbing under the covers, transparently to the UBI volume users.

Erase Counts

  UBI maintains an erase count header per eraseblock. This frees
  higher-level layers (like file systems) from doing this and allows
  for centralized erase count management instead. The erase counts are
  used by the wear-levelling algorithm in the UBI layer. The algorithm
  itself is exchangeable.

Booting from NAND

  For booting directly from NAND flash the hardware must at least be
  capable of fetching and executing a small portion of the NAND
  flash. Some NAND flash controllers have this kind of support. They
  usually limit the window to a few kilobytes in erase block 0. This
  "initial program loader" (IPL) must then contain sufficient logic to
  load and execute the next boot phase.

  Due to bad eraseblocks, which may be randomly scattered over the
  flash device, it is problematic to store the "secondary program
  loader" (SPL) statically. Also, due to bit-flips it may become
  corrupted over time. UBI allows to solve this problem gracefully by
  storing the SPL in a small static UBI volume.

UBI volumes vs. static partitions

  UBI volumes are still very similar to static MTD partitions:

    * both consist of eraseblocks (logical eraseblocks in case of UBI
      volumes, and physical eraseblocks in case of static partitions;
    * both support three basic operations - read, write, erase.

  But UBI volumes have the following advantages over traditional
  static MTD partitions:

    * there are no eraseblock wear-leveling constraints in case of UBI
      volumes, so the user should not care about this;
    * there are no bit-flips and bad eraseblocks in case of UBI volumes.

  So, UBI volumes may be considered as flash devices with relaxed
  restrictions.

Where can it be found?

  Documentation, kernel code and applications can be found in the MTD
  gits.

What are the applications for?

  The applications help to create binary flash images for two
  purposes: pfi files (partial flash images) for in-system update of
  UBI volumes, and plain binary images, with or without OOB data in
  case of NAND, for a manufacturing step. Furthermore some tools
  are/and will be created that allow flash content analysis after a
  system has crashed.

Who did UBI?

  The original ideas, where UBI is based on, were developed by Andreas
  Arnez, Frank Haverkamp and Thomas Gleixner. Josh W. Boyer and
  some others were involved too. The implementation of the kernel
  layer was done by Artem B. Bityutskiy. The user-space applications
  and tools were written by Oliver Lohmann with contributions from
  Frank Haverkamp, Andreas Arnez, and Artem. Joern Engel contributed a
  patch which modifies JFFS2 so that it can be run on a UBI
  volume. Thomas Gleixner did modifications to the NAND layer and also
  some to JFFS2 to make it work.

Signed-off-by: Frank Haverkamp <haver@vnet.ibm.com>

1 files changed, 461 insertions, 0 deletions

diff --git a/ubi-utils/src/libpfi/pfi.c b/ubi-utils/src/libpfi/pfi.c
new file mode 100644
index 0000000..c8d5ee4
--- /dev/null
+++ b/ubi-utils/src/libpfi/pfi.c
@@ -0,0 +1,461 @@
+/*
+ * Copyright (c) International Business Machines Corp., 2006
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/*
+ * @file pfi.c
+ *
+ * @author Oliver Lohmann
+ *	   Andreas Arnez
+ *	   Joern Engel
+ *	   Frank Haverkamp
+ *
+ * @brief libpfi holds all code to create and process pfi files.
+ *
+ * <oliloh@de.ibm.com> Wed Feb	8 11:38:22 CET 2006: Initial creation.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <syslog.h>
+#include <stdarg.h>
+#include <errno.h>
+
+#include "pfi.h"
+
+#define PFI_MAGIC     "PFI!\n"
+#define PFI_DATA      "DATA\n" /* The same size as PFI_MAGIC */
+#define PFI_MAGIC_LEN 5
+
+static const char copyright [] __attribute__((unused)) =
+	"Copyright (c) International Business Machines Corp., 2006";
+
+enum key_id {
+	/* version 1 */
+	key_version,	      /* must be index position 0! */
+	key_mode,
+	key_size,
+	key_crc,
+	key_label,
+	key_flags,
+	key_ubi_ids,
+	key_ubi_size,
+	key_ubi_type,
+	key_ubi_names,
+	key_ubi_alignment,
+	key_raw_starts,
+	key_raw_total_size,
+	num_keys,
+};
+
+struct pfi_header {
+	char defined[num_keys];	 /* reserve all possible keys even if
+				    version does not require this. */
+	int mode_no;		 /* current mode no. -> can only increase */
+	union {
+		char *str;
+		uint32_t num;
+	} value[num_keys];
+};
+
+
+#define PFI_MANDATORY	    0x0001
+#define PFI_STRING	    0x0002
+#define PFI_LISTVALUE	    0x0004	/* comma seperated list of nums */
+#define PFI_MANDATORY_UBI   0x0008
+#define PFI_MANDATORY_RAW   0x0010
+
+struct key_descriptor {
+	enum key_id id;
+	const char *name;
+	uint32_t flags;
+};
+
+static const struct key_descriptor key_desc_v1[] = {
+	{ key_version, "version", PFI_MANDATORY },
+	{ key_mode, "mode", PFI_MANDATORY | PFI_STRING },
+	{ key_size, "size", PFI_MANDATORY },
+	{ key_crc, "crc", PFI_MANDATORY },
+	{ key_label, "label", PFI_MANDATORY | PFI_STRING },
+	{ key_flags, "flags", PFI_MANDATORY },
+	{ key_ubi_ids, "ubi_ids", PFI_MANDATORY_UBI | PFI_STRING },
+	{ key_ubi_size, "ubi_size", PFI_MANDATORY_UBI },
+	{ key_ubi_type, "ubi_type", PFI_MANDATORY_UBI | PFI_STRING },
+	{ key_ubi_names, "ubi_names", PFI_MANDATORY_UBI | PFI_STRING },
+	{ key_ubi_alignment, "ubi_alignment", PFI_MANDATORY_UBI },
+	{ key_raw_starts, "raw_starts", PFI_MANDATORY_RAW | PFI_STRING },
+	{ key_raw_total_size, "raw_total_size", PFI_MANDATORY_RAW },
+};
+
+static const struct key_descriptor *key_descriptors[] = {
+	NULL,
+	key_desc_v1,					   /* version 1 */
+};
+
+static const int key_descriptors_max[] = {
+	0,						   /* version 0 */
+	sizeof(key_desc_v1)/sizeof(struct key_descriptor), /* version 1 */
+};
+
+static const char* modes[] = {"raw", "ubi", NULL}; /* order isn't arbitrary! */
+
+/* latest version contains all possible keys */
+static const struct key_descriptor *key_desc = key_desc_v1;
+
+#define PFI_IS_UBI(mode) \
+	(((mode) != NULL) && (strcmp("ubi", (mode)) == 0))
+
+#define PFI_IS_RAW(mode) \
+	(((mode) != NULL) && (strcmp("raw", (mode)) == 0))
+
+/**
+ * @return	 <0	On Error.
+ *		>=0	Mode no.
+ */
+static int
+get_mode_no(const char* mode)
+{
+	const char* ptr = modes[0];
+	int i = 0;
+	while (ptr != NULL) {
+		if(strcmp(ptr, mode) == 0) {
+			return i;
+		}
+		ptr++;
+		i++;
+	}
+
+	return -1;
+}
+
+static int
+find_key_by_name (const char *name)
+{
+	int i;
+
+	for (i = 0; i < num_keys; i++) {
+		if (strcmp(name, key_desc[i].name) == 0)
+			return i;
+	}
+	return -1;
+}
+
+static int
+check_valid (pfi_header head)
+{
+	int i;
+	int max_keys;
+	uint32_t version;
+	const char *mode;
+	const struct key_descriptor *desc;
+	uint32_t to_check = PFI_MANDATORY;
+
+	/*
+	 * For the validity check the list of possible keys depends on
+	 * the version of the PFI file used.
+	 */
+	version = head->value[key_version].num;
+	if (version > PFI_HDRVERSION)
+		return PFI_ENOHEADER;
+
+	max_keys = key_descriptors_max[version];
+	desc = key_descriptors[version];
+
+	if (!desc)
+		return PFI_ENOVERSION;
+
+	mode = head->value[key_mode].str;
+	if (PFI_IS_UBI(mode)) {
+		to_check |= PFI_MANDATORY_UBI;
+	}
+	else if (PFI_IS_RAW(mode)) {
+		to_check |= PFI_MANDATORY_RAW;
+	}
+	else { /* neither UBI nor RAW == ERR */
+		return PFI_EINSUFF;
+	}
+
+	for (i = 0; i < max_keys; i++) {
+		if ((desc[i].flags & to_check) && !head->defined[i]) {
+			fprintf(stderr, "libpfi: %s missing\n", desc[i].name);
+			return PFI_EINSUFF;
+		}
+	}
+
+	return 0;
+}
+
+int pfi_header_init (pfi_header *head)
+{
+	int i;
+	pfi_header self = (pfi_header) malloc(sizeof(*self));
+
+	*head = self;
+	if (self == NULL)
+		return PFI_ENOMEM;
+
+	/* initialize maximum number of possible keys */
+	for (i = 0; i < num_keys; i++) {
+		memset(self, 0, sizeof(*self));
+		self->defined[i] = 0;
+	}
+
+	return 0;
+}
+
+int pfi_header_destroy (pfi_header *head)
+{
+	int i;
+	pfi_header self = *head;
+
+	for (i = 0; i < num_keys; i++) {
+		if (self->defined[i] && (key_desc[i].flags & PFI_STRING) &&
+		    self->value[i].str) {
+			free(self->value[i].str);
+		}
+	}
+	free(*head);
+	*head = NULL;
+	return 0;
+}
+
+int pfi_header_setnumber (pfi_header head,
+			   const char *key, uint32_t value)
+{
+	int key_id = find_key_by_name(key);
+
+	if (key_id < 0)
+		return PFI_EUNDEF;
+
+	if (key_desc[key_id].flags & PFI_STRING)
+		return PFI_EBADTYPE;
+
+	head->value[key_id].num = value;
+	head->defined[key_id] = 1;
+	return 0;
+}
+
+int pfi_header_setvalue (pfi_header head,
+			  const char *key, const char *value)
+{
+	int key_id = find_key_by_name(key);
+
+	if ((uint32_t)value == (uint32_t)NULL)
+		return PFI_EINSUFF;
+
+	if ((key_id < 0) || (key_id >= num_keys))
+		return PFI_EUNDEF;
+
+	if (key_desc[key_id].flags & PFI_STRING) {
+		/*
+		 * The value is a string. Copy to a newly allocated
+		 * buffer. Delete the old value, if already set.
+		 */
+		size_t len = strlen(value) + 1;
+		char *old_str = NULL;
+		char *str;
+
+		old_str = head->value[key_id].str;
+		if (old_str != NULL)
+			free(old_str);
+
+		str = head->value[key_id].str = (char *) malloc(len);
+		if (str == NULL)
+			return PFI_ENOMEM;
+
+		strcpy(str, value);
+	} else {
+		int len;
+		int ret;
+		/* FIXME: here we assume that the value is always
+		   given in hex and starts with '0x'. */
+		ret = sscanf(value, "0x%x%n", &head->value[key_id].num, &len);
+		if (ret < 1 || value[len] != '\0')
+			return PFI_EBADTYPE;
+	}
+	head->defined[key_id] = 1;
+	return 0;
+}
+
+int pfi_header_getnumber (pfi_header head,
+			   const char *key, uint32_t *value)
+{
+	int key_id = find_key_by_name(key);
+
+	if (key_id < 0)
+		return PFI_EUNDEF;
+
+	if (key_desc[key_id].flags & PFI_STRING)
+		return PFI_EBADTYPE;
+
+	if (!head->defined[key_id])
+		return PFI_EUNDEF;
+
+	*value = head->value[key_id].num;
+	return 0;
+}
+
+int pfi_header_getstring (pfi_header head,
+			   const char *key, char *value, size_t size)
+{
+	int key_id = find_key_by_name(key);
+
+	if (key_id < 0)
+		return PFI_EUNDEF;
+
+	if (!(key_desc[key_id].flags & PFI_STRING))
+		return PFI_EBADTYPE;
+
+	if (!head->defined[key_id])
+		return PFI_EUNDEF;
+
+	strncpy(value, head->value[key_id].str, size-1);
+	value[size-1] = '\0';
+	return 0;
+}
+
+int pfi_header_write (FILE *out, pfi_header head)
+{
+	int i;
+	int ret;
+
+	pfi_header_setnumber(head, "version", PFI_HDRVERSION);
+
+	if ((ret = check_valid(head)) != 0)
+		return ret;
+
+	/* OK.	Now write the header. */
+
+	ret = fwrite(PFI_MAGIC, 1, PFI_MAGIC_LEN, out);
+	if (ret < PFI_MAGIC_LEN)
+		return ret;
+
+
+	for (i = 0; i < num_keys; i++) {
+		if (!head->defined[i])
+			continue;
+
+		ret = fprintf(out, "%s=", key_desc[i].name);
+		if (ret < 0)
+			return PFI_EFILE;
+
+		if (key_desc[i].flags & PFI_STRING) {
+			ret = fprintf(out, "%s", head->value[i].str);
+			if (ret < 0)
+				return PFI_EFILE;
+		} else {
+			ret = fprintf(out, "0x%8x", head->value[i].num);
+			if (ret < 0)
+				return PFI_EFILE;
+
+		}
+		ret = fprintf(out, "\n");
+		if (ret < 0)
+			return PFI_EFILE;
+	}
+	ret = fprintf(out, "\n");
+	if (ret < 0)
+		return PFI_EFILE;
+
+	ret = fflush(out);
+	if (ret != 0)
+		return PFI_EFILE;
+
+	return 0;
+}
+
+int pfi_header_read (FILE *in, pfi_header head)
+{
+	char magic[PFI_MAGIC_LEN];
+	char mode[PFI_KEYWORD_LEN];
+	char buf[256];
+
+	if (PFI_MAGIC_LEN != fread(magic, 1, PFI_MAGIC_LEN, in))
+		return PFI_EFILE;
+	if (memcmp(magic, PFI_MAGIC, PFI_MAGIC_LEN) != 0)  {
+		if (memcmp(magic, PFI_DATA, PFI_MAGIC_LEN) == 0) {
+			return PFI_DATA_START;
+		}
+		return PFI_ENOHEADER;
+	}
+
+	while (fgets(buf, sizeof(buf), in) != NULL && buf[0] != '\n') {
+		char *value;
+		char *end;
+		value = strchr(buf, '=');
+		if (value == NULL)
+			return PFI_ENOHEADER;
+
+		*value = '\0';
+		value++;
+		end = strchr(value, '\n');
+		if (end)
+		       *end = '\0';
+
+		if (pfi_header_setvalue(head, buf, value))
+			return PFI_ENOHEADER;
+	}
+
+	if (check_valid(head) != 0)
+		return PFI_ENOHEADER;
+
+	/* set current mode no. in head */
+	pfi_header_getstring(head, "mode", mode, PFI_KEYWORD_LEN);
+	if (head->mode_no > get_mode_no(mode)) {
+		return PFI_EMODE;
+	}
+	head->mode_no = get_mode_no(mode);
+	return 0;
+}
+
+int pfi_header_dump (FILE *out, pfi_header head __attribute__((__unused__)))
+{
+	fprintf(out, "Sorry not implemented yet. Write mail to "
+		"Andreas Arnez and complain!\n");
+	return 0;
+}
+
+int pfi_read (FILE *in, pfi_read_func func, void *priv_data)
+{
+	int rc;
+	pfi_header header;
+
+	rc = pfi_header_init (&header);
+	if (0 != rc)
+		return rc;
+	if (!func)
+		return PFI_EINVAL;
+
+	while ((0 == rc) && !feof(in)) {
+		/*
+		 * Read header and check consistency of the fields.
+		 */
+		rc = pfi_header_read( in, header );
+		if (0 != rc)
+			break;
+		if (func) {
+			rc = func(in, header, priv_data);
+			if (rc != 0)
+				break;
+		}
+	}
+
+	pfi_header_destroy(&header);
+	return rc;
+}