jffs2_1pass.c

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/*
-------------------------------------------------------------------------
 * Filename:      jffs2.c
 * Version:       $Id: jffs2_1pass.c,v 1.1.1.1 2005/06/27 17:03:40 linuxpark Exp $
 * Copyright:     Copyright (C) 2001, Russ Dill
 * Author:        Russ Dill <[e-mail]>
 * Description:   Module to load kernel from jffs2
 *-----------------------------------------------------------------------*/
/*
 * some portions of this code are taken from jffs2, and as such, the
 * following copyright notice is included.
 *
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright (C) 2001 Red Hat, Inc.
 *
 * Created by David Woodhouse <[e-mail]>
 *
 * The original JFFS, from which the design for JFFS2 was derived,
 * was designed and implemented by Axis Communications AB.
 *
 * The contents of this file are subject to the Red Hat eCos Public
 * License Version 1.1 (the "Licence"); you may not use this file
 * except in compliance with the Licence.  You may obtain a copy of
 * the Licence at http://www.redhat.com/
 *
 * Software distributed under the Licence is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.
 * See the Licence for the specific language governing rights and
 * limitations under the Licence.
 *
 * The Original Code is JFFS2 - Journalling Flash File System, version 2
 *
 * Alternatively, the contents of this file may be used under the
 * terms of the GNU General Public License version 2 (the "GPL"), in
 * which case the provisions of the GPL are applicable instead of the
 * above.  If you wish to allow the use of your version of this file
 * only under the terms of the GPL and not to allow others to use your
 * version of this file under the RHEPL, indicate your decision by
 * deleting the provisions above and replace them with the notice and
 * other provisions required by the GPL.  If you do not delete the
 * provisions above, a recipient may use your version of this file
 * under either the RHEPL or the GPL.
 *
 * $Id: jffs2_1pass.c,v 1.1.1.1 2005/06/27 17:03:40 linuxpark Exp $
 *
 */

/* Ok, so anyone who knows the jffs2 code will probably want to get a papar
 * bag to throw up into before reading this code. I looked through the jffs2
 * code, the caching scheme is very elegant. I tried to keep the version
 * for a bootloader as small and simple as possible. Instead of worring about
 * unneccesary data copies, node scans, etc, I just optimized for the known
 * common case, a kernel, which looks like:
 * 	(1) most pages are 4096 bytes
 *	(2) version numbers are somewhat sorted in acsending order
 *	(3) multiple compressed blocks making up one page is uncommon
 *
 * So I create a linked list of decending version numbers (insertions at the
 * head), and then for each page, walk down the list, until a matching page
 * with 4096 bytes is found, and then decompress the watching pages in
 * reverse order.
 *
 */

/*
 * Adapted by Nye Liu <[e-mail]> and
 * Rex Feany <[e-mail]>
 * on Jan/2002 for U-Boot.
 *
 * Clipped out all the non-1pass functions, cleaned up warnings,
 * wrappers, etc. No major changes to the code.
 * Please, he really means it when he said have a paper bag
 * handy. We needed it ;).
 *
 */

/*
 * Bugfixing by Kai-Uwe Bloem <[e-mail]>, (C) Mar/2003
 *
 * - overhaul of the memory management. Removed much of the "paper-bagging"
 *   in that part of the code, fixed several bugs, now frees memory when
 *   partition is changed.
 *   It's still ugly :-(
 * - fixed a bug in jffs2_1pass_read_inode where the file length calculation
 *   was incorrect. Removed a bit of the paper-bagging as well.
 * - removed double crc calculation for fragment headers in jffs2_private.h
 *   for speedup.
 * - scan_empty rewritten in a more "standard" manner (non-paperbag, that is).
 * - spinning wheel now spins depending on how much memory has been scanned
 * - lots of small changes all over the place to "improve" readability.
 * - implemented fragment sorting to ensure that the newest data is copied
 *   if there are multiple copies of fragments for a certain file offset.
 *
 * The fragment sorting feature must be enabled by CFG_JFFS2_SORT_FRAGMENTS.
 * Sorting is done while adding fragments to the lists, which is more or less a
 * bubble sort. This takes a lot of time, and is most probably not an issue if
 * the boot filesystem is always mounted readonly.
 *
 * You should define it if the boot filesystem is mounted writable, and updates
 * to the boot files are done by copying files to that filesystem.
 *
 *
 * There's a big issue left: endianess is completely ignored in this code. Duh!
 *
 *
 * You still should have paper bags at hand :-(. The code lacks more or less
 * any comment, and is still arcane and difficult to read in places. As this
 * might be incompatible with any new code from the jffs2 maintainers anyway,
 * it should probably be dumped and replaced by something like jffs2reader!
 */


#include <common.h>
#include <config.h>
#include <malloc.h>
#include <linux/stat.h>
#include <linux/time.h>

#if (CONFIG_COMMANDS & CFG_CMD_JFFS2)

#include <jffs2/jffs2.h>
#include <jffs2/jffs2_1pass.h>

#include "jffs2_private.h"


#define	NODE_CHUNK  	1024	/* size of memory allocation chunk in b_nodes */
#define	SPIN_BLKSIZE	18  	/* spin after having scanned 1<<BLKSIZE bytes */

/* Debugging switches */
#undef	DEBUG_DIRENTS		/* print directory entry list after scan */
#undef	DEBUG_FRAGMENTS		/* print fragment list after scan */
#undef	DEBUG   			/* enable debugging messages */


#ifdef  DEBUG
# define DEBUGF(fmt,args...)	printf(fmt ,##args)
#else
# define DEBUGF(fmt,args...)
#endif

#if defined(CONFIG_JFFS2_NAND) && (CONFIG_COMMANDS & CFG_CMD_NAND)

/*
 * Support for jffs2 on top of NAND-flash
 *
 * NAND memory isn't mapped in processor's address space,
 * so data should be fetched from flash before
 * being processed. This is exactly what functions declared
 * here do.
 *
 */

/* this one defined in cmd_nand.c */
int read_jffs2_nand(size_t start, size_t len,
		    size_t * retlen, u_char * buf, int nanddev);

#define NAND_PAGE_SIZE 512
#define NAND_PAGE_SHIFT 9
#define NAND_PAGE_MASK (~(NAND_PAGE_SIZE-1))

#ifndef NAND_CACHE_PAGES
#define NAND_CACHE_PAGES 16
#endif
#define NAND_CACHE_SIZE (NAND_CACHE_PAGES*NAND_PAGE_SIZE)

static u8* nand_cache = NULL;
static u32 nand_cache_off = (u32)-1;
static int nanddev = 0; /* nand device of current partition */

static int read_nand_cached(u32 off, u32 size, u_char *buf)
{
	u32 bytes_read = 0;
	size_t retlen;
	int cpy_bytes;

	while (bytes_read < size) {
		if ((off + bytes_read < nand_cache_off) ||
		    (off + bytes_read >= nand_cache_off+NAND_CACHE_SIZE)) {
			nand_cache_off = (off + bytes_read) & NAND_PAGE_MASK;
			if (!nand_cache) {
				/* This memory never gets freed but 'cause
				   it's a bootloader, nobody cares */
				nand_cache = malloc(NAND_CACHE_SIZE);
				if (!nand_cache) {
					printf("read_nand_cached: can't alloc cache size %d bytes\n",
					       NAND_CACHE_SIZE);
					return -1;
				}
			}
			if (read_jffs2_nand(nand_cache_off, NAND_CACHE_SIZE,
					    &retlen, nand_cache, nanddev) < 0 ||
			    retlen != NAND_CACHE_SIZE) {
				printf("read_nand_cached: error reading nand off %#x size %d bytes\n",
				       nand_cache_off, NAND_CACHE_SIZE);
				return -1;
			}
		}
		cpy_bytes = nand_cache_off + NAND_CACHE_SIZE - (off + bytes_read);
		if (cpy_bytes > size - bytes_read)
			cpy_bytes = size - bytes_read;
		memcpy(buf + bytes_read,
		       nand_cache + off + bytes_read - nand_cache_off,
		       cpy_bytes);
		bytes_read += cpy_bytes;
	}
	return bytes_read;
}

static void *get_fl_mem(u32 off, u32 size, void *ext_buf)
{
	u_char *buf = ext_buf ? (u_char*)ext_buf : (u_char*)malloc(size);

	if (NULL == buf) {
		printf("get_fl_mem: can't alloc %d bytes\n", size);
		return NULL;
	}
	if (read_nand_cached(off, size, buf) < 0) {
		if (!ext_buf)
			free(buf);
		return NULL;
	}

	return buf;
}

static void *get_node_mem(u32 off)
{
	struct jffs2_unknown_node node;
	void *ret = NULL;

	if (NULL == get_fl_mem(off, sizeof(node), &node))
		return NULL;

	if (!(ret = get_fl_mem(off, node.magic ==
			       JFFS2_MAGIC_BITMASK ? node.totlen : sizeof(node),
			       NULL))) {
		printf("off = %#x magic %#x type %#x node.totlen = %d\n",
		       off, node.magic, node.nodetype, node.totlen);
	}
	return ret;
}

static void put_fl_mem(void *buf)
{
	free(buf);
}

#else /* defined(CONFIG_JFFS2_NAND) && (CONFIG_COMMANDS & CFG_CMD_NAND) */

static inline void *get_fl_mem(u32 off, u32 size, void *ext_buf)
{
	return (void*)off;
}

static inline void *get_node_mem(u32 off)
{
	return (void*)off;
}

static inline void put_fl_mem(void *buf)
{
}

#endif /* defined(CONFIG_JFFS2_NAND) && (CONFIG_COMMANDS & CFG_CMD_NAND) */


/* Compression names */
static char *compr_names[] = {
	"NONE",
	"ZERO",
	"RTIME",
	"RUBINMIPS",
	"COPY",
	"DYNRUBIN",
	"ZLIB"
};

/* Spinning wheel */
static char spinner[] = { '|', '/', '-', '\\' };

/* Memory management */
struct mem_block {
	u32	index;
	struct mem_block *next;
	struct b_node nodes[NODE_CHUNK];
};


static void
free_nodes(struct b_list *list)
{
	while (list->listMemBase != NULL) {
		struct mem_block *next = list->listMemBase->next;
		free( list->listMemBase );
		list->listMemBase = next;
	}
}

static struct b_node *
add_node(struct b_list *list)
{
	u32 index = 0;
	struct mem_block *memBase;
	struct b_node *b;

	memBase = list->listMemBase;
	if (memBase != NULL)
		index = memBase->index;
#if 0
	putLabeledWord("add_node: index = ", index);
	putLabeledWord("add_node: memBase = ", list->listMemBase);
#endif

	if (memBase == NULL || index >= NODE_CHUNK) {
		/* we need more space before we continue */
		memBase = mmalloc(sizeof(struct mem_block));
		if (memBase == NULL) {
			putstr("add_node: malloc failed\n");
			return NULL;
		}
		memBase->next = list->listMemBase;
		index = 0;
#if 0
		putLabeledWord("add_node: alloced a new membase at ", *memBase);
#endif

	}
	/* now we have room to add it. */
	b = &memBase->nodes[index];
	index ++;

	memBase->index = index;
	list->listMemBase = memBase;
	list->listCount++;
	return b;
}

static struct b_node *
insert_node(struct b_list *list, u32 offset)
{
	struct b_node *new;
#ifdef CFG_JFFS2_SORT_FRAGMENTS
	struct b_node *b, *prev;
#endif

	if (!(new = add_node(list))) {
		putstr("add_node failed!\r\n");
		return NULL;
	}
	new->offset = offset;

#ifdef CFG_JFFS2_SORT_FRAGMENTS
	if (list->listTail != NULL && list->listCompare(new, list->listTail))
		prev = list->listTail;
	else if (list->listLast != NULL && list->listCompare(new, list->listLast))
		prev = list->listLast;
	else
		prev = NULL;

	for (b = (prev ? prev->next : list->listHead);
	     b != NULL && list->listCompare(new, b);
	     prev = b, b = b->next) {
		list->listLoops++;
	}
	if (b != NULL)
		list->listLast = prev;

	if (b != NULL) {
		new->next = b;
		if (prev != NULL)
			prev->next = new;
		else
			list->listHead = new;
	} else
#endif
	{
		new->next = (struct b_node *) NULL;
		if (list->listTail != NULL) {
			list->listTail->next = new;
			list->listTail = new;
		} else {
			list->listTail = list->listHead = new;
		}
	}

	return new;
}

#ifdef CFG_JFFS2_SORT_FRAGMENTS
/* Sort data entries with the latest version last, so that if there
 * is overlapping data the latest version will be used.
 */
static int compare_inodes(struct b_node *new, struct b_node *old)
{
	struct jffs2_raw_inode ojNew;
	struct jffs2_raw_inode ojOld;
	struct jffs2_raw_inode *jNew =
		(struct jffs2_raw_inode *)get_fl_mem(new->offset, sizeof(ojNew), &ojNew);
	struct jffs2_raw_inode *jOld =
		(struct jffs2_raw_inode *)get_fl_mem(old->offset, sizeof(ojOld), &ojOld);

	return jNew->version > jOld->version;
}

/* Sort directory entries so all entries in the same directory
 * with the same name are grouped together, with the latest version
 * last. This makes it easy to eliminate all but the latest version
 * by marking the previous version dead by setting the inode to 0.
 */
static int compare_dirents(struct b_node *new, struct b_node *old)
{
	struct jffs2_raw_dirent ojNew;
	struct jffs2_raw_dirent ojOld;
	struct jffs2_raw_dirent *jNew =
		(struct jffs2_raw_dirent *)get_fl_mem(new->offset, sizeof(ojNew), &ojNew);
	struct jffs2_raw_dirent *jOld =
		(struct jffs2_raw_dirent *)get_fl_mem(old->offset, sizeof(ojOld), &ojOld);
	int cmp;

	/* ascending sort by pino */
	if (jNew->pino != jOld->pino)
		return jNew->pino > jOld->pino;

	/* pino is the same, so use ascending sort by nsize, so
	 * we don't do strncmp unless we really must.
	 */
	if (jNew->nsize != jOld->nsize)
		return jNew->nsize > jOld->nsize;

	/* length is also the same, so use ascending sort by name
	 */