jffs2_1pass.c

AT91RM9200的完整启动代码：包括loader, boot及U-boot三部分均已编译通过！欢迎下载使用！

/* vi: set sw=4 ts=4: */
/*
-------------------------------------------------------------------------
 * Filename:      jffs2.c
 * Version:       $Id: jffs2_1pass.c,v 1.7 2002/01/25 01:56:47 nyet 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 1.7 2002/01/25 01:56:47 nyet 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
 * is 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


/* 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
static int compare_inodes(struct b_node *new, struct b_node *old)
{
	struct jffs2_raw_inode *jNew = (struct jffs2_raw_inode *)new->offset;
	struct jffs2_raw_inode *jOld = (struct jffs2_raw_inode *)old->offset;

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

static int compare_dirents(struct b_node *new, struct b_node *old)
{
	struct jffs2_raw_dirent *jNew = (struct jffs2_raw_dirent *)new->offset;
	struct jffs2_raw_dirent *jOld = (struct jffs2_raw_dirent *)old->offset;

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

static u32
jffs2_scan_empty(u32 start_offset, struct part_info *part)
{
	char *max = part->offset + part->size - sizeof(struct jffs2_raw_inode);
	char *offset = part->offset + start_offset;

	while (offset < max && *(u32 *)offset == 0xFFFFFFFF) {
		offset += sizeof(u32);
		/* return if spinning is due */
		if (((u32)offset & ((1 << SPIN_BLKSIZE)-1)) == 0) break;
	}

	return offset - part->offset;
}

static u32
jffs_init_1pass_list(struct part_info *part)
{
	struct b_lists *pL;

	if (part->jffs2_priv != NULL) {
		pL = (struct b_lists *)part->jffs2_priv;
		free_nodes(&pL->frag);
		free_nodes(&pL->dir);
		free(pL);
	}
	if (NULL != (part->jffs2_priv = malloc(sizeof(struct b_lists)))) {
		pL = (struct b_lists *)part->jffs2_priv;

		memset(pL, 0, sizeof(*pL));
#ifdef CFG_JFFS2_SORT_FRAGMENTS
		pL->dir.listCompare = compare_dirents;
		pL->frag.listCompare = compare_inodes;
#endif
	}
	return 0;
}

/* find the inode from the slashless name given a parent */
static long
jffs2_1pass_read_inode(struct b_lists *pL, u32 inode, char *dest)
{
	struct b_node *b;
	struct jffs2_raw_inode *jNode;
	u32 totalSize = 0;
	u16 latestVersion = 0;
	char *lDest;
	char *src;
	long ret;
	int i;
	u32 counter = 0;

	for (b = pL->frag.listHead; b != NULL; b = b->next) {
		jNode = (struct jffs2_raw_inode *) (b->offset);
		if ((inode == jNode->ino)) {
#if 0
			putLabeledWord("\r\n\r\nread_inode: totlen = ", jNode->totlen);
			putLabeledWord("read_inode: inode = ", jNode->ino);
			putLabeledWord("read_inode: version = ", jNode->version);
			putLabeledWord("read_inode: isize = ", jNode->isize);
			putLabeledWord("read_inode: offset = ", jNode->offset);
			putLabeledWord("read_inode: csize = ", jNode->csize);
			putLabeledWord("read_inode: dsize = ", jNode->dsize);
			putLabeledWord("read_inode: compr = ", jNode->compr);
			putLabeledWord("read_inode: usercompr = ", jNode->usercompr);
			putLabeledWord("read_inode: flags = ", jNode->flags);
#endif
			/* get actual file length from the newest node */
			if (jNode->version >= latestVersion) {
				totalSize = jNode->isize;
				latestVersion = jNode->version;
			}

			if(dest) {
				src = ((char *) jNode) + sizeof(struct jffs2_raw_inode);
				/* ignore data behind latest known EOF */
				if (jNode->offset > totalSize)
					continue;

				lDest = (char *) (dest + jNode->offset);
#if 0
				putLabeledWord("read_inode: src = ", src);
				putLabeledWord("read_inode: dest = ", lDest);
#endif
				switch (jNode->compr) {
				case JFFS2_COMPR_NONE:
					ret = (unsigned long) ldr_memcpy(lDest, src, jNode->dsize);
					break;
				case JFFS2_COMPR_ZERO:
					ret = 0;
					for (i = 0; i < jNode->dsize; i++)
						*(lDest++) = 0;
					break;
				case JFFS2_COMPR_RTIME:
					ret = 0;
					rtime_decompress(src, lDest, jNode->csize, jNode->dsize);
					break;
				case JFFS2_COMPR_DYNRUBIN:
					/* this is slow but it works */
					ret = 0;
					dynrubin_decompress(src, lDest, jNode->csize, jNode->dsize);
					break;
				case JFFS2_COMPR_ZLIB:
					ret = zlib_decompress(src, lDest, jNode->csize, jNode->dsize);
					break;
				default:
					/* unknown */
					putLabeledWord("UNKOWN COMPRESSION METHOD = ", jNode->compr);
					return -1;
					break;
				}
			}

#if 0
			putLabeledWord("read_inode: totalSize = ", totalSize);
			putLabeledWord("read_inode: compr ret = ", ret);
#endif
		}
		counter++;
	}

#if 0
	putLabeledWord("read_inode: returning = ", totalSize);
#endif
	return totalSize;
}

/* find the inode from the slashless name given a parent */
static u32
jffs2_1pass_find_inode(struct b_lists * pL, const char *name, u32 pino)
{
	struct b_node *b;
	struct jffs2_raw_dirent *jDir;
	int len;
	u32 counter;
	u32 version = 0;
	u32 inode = 0;

	/* name is assumed slash free */
	len = strlen(name);

	counter = 0;
	/* we need to search all and return the inode with the highest version */
	for(b = pL->dir.listHead; b; b = b->next, counter++) {
		jDir = (struct jffs2_raw_dirent *) (b->offset);
		if ((pino == jDir->pino) && (len == jDir->nsize) &&
		    (jDir->ino) &&	/* 0 for unlink */
		    (!strncmp(jDir->name, name, len))) {	/* a match */
			if (jDir->version < version) continue;

		        if(jDir->version == 0) {
			    	/* Is this legal? */
				putstr(" ** WARNING ** ");
				putnstr(jDir->name, jDir->nsize);
				putstr(" is version 0 (in find, ignoring)\r\n");
			} else if(jDir->version == version) {
			    	/* Im pretty sure this isn't ... */
				putstr(" ** ERROR ** ");
				putnstr(jDir->name, jDir->nsize);
				putLabeledWord(" has dup version =", version);
			}
			inode = jDir->ino;
			version = jDir->version;
		}
#if 0
		putstr("\r\nfind_inode:p&l ->");
		putnstr(jDir->name, jDir->nsize);
		putstr("\r\n");
		putLabeledWord("pino = ", jDir->pino);
		putLabeledWord("nsize = ", jDir->nsize);
		putLabeledWord("b = ", (u32) b);
		putLabeledWord("counter = ", counter);
#endif
	}
	return inode;
}

static char *mkmodestr(unsigned long mode, char *str)
{
	static const char *l = "xwr";
	int mask = 1, i;
	char c;

	switch (mode & S_IFMT) {
		case S_IFDIR:    str[0] = 'd'; break;
		case S_IFBLK:    str[0] = 'b'; break;
		case S_IFCHR:    str[0] = 'c'; break;
		case S_IFIFO:    str[0] = 'f'; break;
		case S_IFLNK:    str[0] = 'l'; break;
		case S_IFSOCK:   str[0] = 's'; break;
		case S_IFREG:    str[0] = '-'; break;
		default:         str[0] = '?';
	}

	for(i = 0; i < 9; i++) {
		c = l[i%3];
		str[9-i] = (mode & mask)?c:'-';
		mask = mask<<1;
	}

	if(mode & S_ISUID) str[3] = (mode & S_IXUSR)?'s':'S';
	if(mode & S_ISGID) str[6] = (mode & S_IXGRP)?'s':'S';
	if(mode & S_ISVTX) str[9] = (mode & S_IXOTH)?'t':'T';
	str[10] = '\0';
	return str;
}

static inline void dump_stat(struct stat *st, const char *name)
{
	char str[20];
	char s[64], *p;

	if (st->st_mtime == (time_t)(-1)) /* some ctimes really hate -1 */
		st->st_mtime = 1;

	ctime_r(&st->st_mtime, s/*,64*/); /* newlib ctime doesn't have buflen */

	if ((p = strchr(s,'\n')) != NULL) *p = '\0';
	if ((p = strchr(s,'\r')) != NULL) *p = '\0';

/*
	printf("%6lo %s %8ld %s %s\n", st->st_mode, mkmodestr(st->st_mode, str),
		st->st_size, s, name);
*/

	printf(" %s %8ld %s %s", mkmodestr(st->st_mode,str), st->st_size, s, name);
}

static inline u32 dump_inode(struct b_lists * pL, struct jffs2_raw_dirent *d, struct jffs2_raw_inode *i)
{
	char fname[256];
	struct stat st;

	if(!d || !i) return -1;

	strncpy(fname, d->name, d->nsize);
	fname[d->nsize] = '\0';

	memset(&st,0,sizeof(st));

	st.st_mtime = i->mtime;
	st.st_mode = i->mode;
	st.st_ino = i->ino;

	/* neither dsize nor isize help us.. do it the long way */
	st.st_size = jffs2_1pass_read_inode(pL, i->ino, NULL);

	dump_stat(&st, fname);