add-ext2-fs.patch

This adds ext2 support from U-Boot and stitches it into the
partition stuff.  It also upgrades the board definitions so they
can define the path to look for in the ext2 filesystem being
mounted.  I used /boot/uImage.bin because this is already in use
by the packaged kernel.

We now mount, open and pull the kernel from ext2 in phase2.c if
the kernel source defines it.

Signed-off-by: Andy Green <andy@openmoko.com>

qiboot/src/fs/dev.c

@@ -0,0 +1,115 @@
+/*
+ * (C) Copyright 2004
+ *  esd gmbh <www.esd-electronics.com>
+ *  Reinhard Arlt <reinhard.arlt@esd-electronics.com>
+ *
+ *  based on code of fs/reiserfs/dev.c by
+ *
+ *  (C) Copyright 2003 - 2004
+ *  Sysgo AG, <www.elinos.com>, Pavel Bartusek <pba@sysgo.com>
+ *
+ *  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.
+ */
+
+
+#include <qi.h>
+#include <ext2.h>
+#include <string.h>
+
+extern unsigned long partition_offset_blocks;
+extern unsigned long partition_length_blocks;
+
+
+int ext2fs_devread(int sector, int byte_offset, int byte_len, u8 *buf)
+{
+	unsigned char sec_buf[SECTOR_SIZE];
+	unsigned block_len;
+
+/*
+ *  Check partition boundaries
+ */
+	if ((sector < 0)
+	    || ((sector + ((byte_offset + byte_len - 1) >> SECTOR_BITS)) >=
+						     partition_length_blocks)) {
+	/*      errnum = ERR_OUTSIDE_PART; */
+		puts(" ** ext2fs_devread() read outside partition sector ");
+		printdec(sector);
+		puts("\n");
+		return 0;
+	}
+
+/*
+ *  Get the read to the beginning of a partition.
+ */
+	sector += byte_offset >> SECTOR_BITS;
+	byte_offset &= SECTOR_SIZE - 1;
+
+	if (byte_offset) {
+		int minimum = SECTOR_SIZE - byte_offset;
+
+		if (byte_len < minimum)
+			minimum = byte_len;
+
+		/* read first part which isn't aligned with start of sector */
+		if ((this_kernel->block_read)(sec_buf,
+				partition_offset_blocks + sector, 1) < 0) {
+			puts(" ** ext2fs_devread() read error **\n");
+			return 0;
+		}
+		memcpy(buf, sec_buf + byte_offset,
+			minimum);
+		buf += minimum;
+		byte_len -= minimum;
+		sector++;
+	}
+
+	if (!byte_len)
+		return 1;
+
+	/*  read sector aligned part */
+	block_len = byte_len & ~(SECTOR_SIZE - 1);
+
+	if (block_len == 0) {
+		u8 p[SECTOR_SIZE];
+
+		block_len = SECTOR_SIZE;
+		this_kernel->block_read(p,
+		       partition_offset_blocks + sector, 1);
+		memcpy(buf, p, byte_len);
+		return 1;
+	}
+
+	if (this_kernel->block_read(buf, partition_offset_blocks + sector,
+			  block_len / SECTOR_SIZE) < 0) {
+		puts(" ** ext2fs_devread() read error - block\n");
+		return 0;
+	}
+	block_len = byte_len & ~(SECTOR_SIZE - 1);
+	buf += block_len;
+	byte_len -= block_len;
+	sector += block_len / SECTOR_SIZE;
+
+	if (byte_len) {
+		/* read rest of data which are not in whole sector */
+		if (this_kernel->block_read(sec_buf,
+				partition_offset_blocks + sector, 1) != 1) {
+			puts(" ** ext2fs_devread() read error - last part\n");
+			return 0;
+		}
+		memcpy (buf, sec_buf, byte_len);
+	}
+	return 1;
+}
+

qiboot/src/fs/ext2.c

@@ -0,0 +1,867 @@
+/*
+ *(C) Copyright 2004
+ *  esd gmbh <www.esd-electronics.com>
+ *  Reinhard Arlt <reinhard.arlt@esd-electronics.com>
+ *
+ *  based on code from grub2 fs/ext2.c and fs/fshelp.c by
+ *
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright(C) 2003, 2004  Free Software Foundation, Inc.
+ *
+ *  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.
+ */
+
+#include <qi.h>
+
+#include <ext2.h>
+#include <malloc.h>
+#include <string.h>
+
+extern int ext2fs_devread(int sector, int byte_offset, int byte_len,
+			   char *buf);
+
+/* Magic value used to identify an ext2 filesystem.  */
+#define	EXT2_MAGIC		0xEF53
+/* Amount of indirect blocks in an inode.  */
+#define INDIRECT_BLOCKS		12
+/* Maximum lenght of a pathname.  */
+#define EXT2_PATH_MAX		4096
+/* Maximum nesting of symlinks, used to prevent a loop.  */
+#define	EXT2_MAX_SYMLINKCNT	8
+
+/* Filetype used in directory entry.  */
+#define	FILETYPE_UNKNOWN	0
+#define	FILETYPE_REG		1
+#define	FILETYPE_DIRECTORY	2
+#define	FILETYPE_SYMLINK	7
+
+/* Filetype information as used in inodes.  */
+#define FILETYPE_INO_MASK	0170000
+#define FILETYPE_INO_REG	0100000
+#define FILETYPE_INO_DIRECTORY	0040000
+#define FILETYPE_INO_SYMLINK	0120000
+
+/* Bits used as offset in sector */
+#define DISK_SECTOR_BITS        9
+
+/* Log2 size of ext2 block in 512 blocks.  */
+#define LOG2_EXT2_BLOCK_SIZE(data)(__le32_to_cpu(data->sblock.log2_block_size) + 1)
+
+/* Log2 size of ext2 block in bytes.  */
+#define LOG2_BLOCK_SIZE(data)	  (__le32_to_cpu(data->sblock.log2_block_size) + 10)
+
+/* The size of an ext2 block in bytes.  */
+#define EXT2_BLOCK_SIZE(data)	  (1 << LOG2_BLOCK_SIZE(data))
+
+/* The ext2 superblock.  */
+struct ext2_sblock {
+	uint32_t total_inodes;
+	uint32_t total_blocks;
+	uint32_t reserved_blocks;
+	uint32_t free_blocks;
+	uint32_t free_inodes;
+	uint32_t first_data_block;
+	uint32_t log2_block_size;
+	uint32_t log2_fragment_size;
+	uint32_t blocks_per_group;
+	uint32_t fragments_per_group;
+	uint32_t inodes_per_group;
+	uint32_t mtime;
+	uint32_t utime;
+	uint16_t mnt_count;
+	uint16_t max_mnt_count;
+	uint16_t magic;
+	uint16_t fs_state;
+	uint16_t error_handling;
+	uint16_t minor_revision_level;
+	uint32_t lastcheck;
+	uint32_t checkinterval;
+	uint32_t creator_os;
+	uint32_t revision_level;
+	uint16_t uid_reserved;
+	uint16_t gid_reserved;
+	uint32_t first_inode;
+	uint16_t inode_size;
+	uint16_t block_group_number;
+	uint32_t feature_compatibility;
+	uint32_t feature_incompat;
+	uint32_t feature_ro_compat;
+	uint32_t unique_id[4];
+	char volume_name[16];
+	char last_mounted_on[64];
+	uint32_t compression_info;
+};
+
+/* The ext2 blockgroup.  */
+struct ext2_block_group {
+	uint32_t block_id;
+	uint32_t inode_id;
+	uint32_t inode_table_id;
+	uint16_t free_blocks;
+	uint16_t free_inodes;
+	uint16_t pad;
+	uint32_t reserved[3];
+};
+
+/* The ext2 inode.  */
+struct ext2_inode {
+	uint16_t mode;
+	uint16_t uid;
+	uint32_t size;
+	uint32_t atime;
+	uint32_t ctime;
+	uint32_t mtime;
+	uint32_t dtime;
+	uint16_t gid;
+	uint16_t nlinks;
+	uint32_t blockcnt;	/* Blocks of 512 bytes!! */
+	uint32_t flags;
+	uint32_t osd1;
+	union {
+		struct datablocks {
+			uint32_t dir_blocks[INDIRECT_BLOCKS];
+			uint32_t indir_block;
+			uint32_t double_indir_block;
+			uint32_t tripple_indir_block;
+		} blocks;
+		char symlink[60];
+	} b;
+	uint32_t version;
+	uint32_t acl;
+	uint32_t dir_acl;
+	uint32_t fragment_addr;
+	uint32_t osd2[3];
+};
+
+/* The header of an ext2 directory entry.  */
+struct ext2_dirent {
+	uint32_t inode;
+	uint16_t direntlen;
+	uint8_t namelen;
+	uint8_t filetype;
+};
+
+struct ext2fs_node {
+	struct ext2_data *data;
+	struct ext2_inode inode;
+	int ino;
+	int inode_read;
+};
+
+/* Information about a "mounted" ext2 filesystem.  */
+struct ext2_data {
+	struct ext2_sblock sblock;
+	struct ext2_inode *inode;
+	struct ext2fs_node diropen;
+};
+
+
+typedef struct ext2fs_node *ext2fs_node_t;
+
+struct ext2_data *ext2fs_root = NULL;
+ext2fs_node_t ext2fs_file = NULL;
+int symlinknest = 0;
+uint32_t *indir1_block = NULL;
+int indir1_size = 0;
+int indir1_blkno = -1;
+uint32_t *indir2_block = NULL;
+int indir2_size = 0;
+int indir2_blkno = -1;
+
+
+static int ext2fs_blockgroup
+	(struct ext2_data *data, int group, struct ext2_block_group *blkgrp) {
+#ifdef DEBUG
+	puts("ext2fs read blockgroup\n");
+#endif
+	return ext2fs_devread
+		(((__le32_to_cpu(data->sblock.first_data_block) +
+		   1) << LOG2_EXT2_BLOCK_SIZE(data)),
+		 group * sizeof(struct ext2_block_group),
+		 sizeof(struct ext2_block_group),(char *) blkgrp);
+}
+
+
+static int ext2fs_read_inode
+	(struct ext2_data *data, int ino, struct ext2_inode *inode) {
+	struct ext2_block_group blkgrp;
+	struct ext2_sblock *sblock = &data->sblock;
+	int inodes_per_block;
+	int status;
+
+	unsigned int blkno;
+	unsigned int blkoff;
+
+	/* It is easier to calculate if the first inode is 0.  */
+	ino--;
+#ifdef DEBUG
+	puts("ext2fs read inode %d\n", ino);
+#endif
+	status = ext2fs_blockgroup(data,
+				    ino /
+				    __le32_to_cpu(sblock->inodes_per_group),
+				    &blkgrp);
+	if (status == 0)
+		return 0;
+
+	inodes_per_block = EXT2_BLOCK_SIZE(data) / 128;
+	blkno =(ino % __le32_to_cpu(sblock->inodes_per_group)) /
+		inodes_per_block;
+	blkoff =(ino % __le32_to_cpu(sblock->inodes_per_group)) %
+		inodes_per_block;
+#ifdef DEBUG
+	puts("ext2fs read inode blkno %d blkoff %d\n", blkno, blkoff);
+#endif
+	/* Read the inode.  */
+	status = ext2fs_devread(((__le32_to_cpu(blkgrp.inode_table_id) +
+				   blkno) << LOG2_EXT2_BLOCK_SIZE(data)),
+				 sizeof(struct ext2_inode) * blkoff,
+				 sizeof(struct ext2_inode),(char *) inode);
+
+	return !!status;
+}
+
+
+void ext2fs_free_node(ext2fs_node_t node, ext2fs_node_t currroot) {
+	if ((node != &ext2fs_root->diropen) &&(node != currroot)) {
+		free(node);
+	}
+}
+
+
+static int ext2fs_read_block(ext2fs_node_t node, int fileblock) {
+	struct ext2_data *data = node->data;
+	struct ext2_inode *inode = &node->inode;
+	int blknr;
+	int blksz = EXT2_BLOCK_SIZE(data);
+	int log2_blksz = LOG2_EXT2_BLOCK_SIZE(data);
+	int status;
+
+	/* Direct blocks.  */
+	if (fileblock < INDIRECT_BLOCKS) {
+		blknr = __le32_to_cpu(inode->b.blocks.dir_blocks[fileblock]);
+	}
+	/* Indirect.  */
+	else if (fileblock <(INDIRECT_BLOCKS +(blksz / 4))) {
+		if (indir1_block == NULL) {
+			indir1_block =(uint32_t *) malloc(blksz);
+			if (indir1_block == NULL) {
+				puts("** ext2fs read block(indir 1) malloc failed. **\n");
+				return -1;
+			}
+			indir1_size = blksz;
+			indir1_blkno = -1;
+		}
+		if (blksz != indir1_size) {
+			free(indir1_block);
+			indir1_block = NULL;
+			indir1_size = 0;
+			indir1_blkno = -1;
+			indir1_block =(uint32_t *) malloc(blksz);
+			if (indir1_block == NULL) {
+				puts("** ext2fs read block(indir 1) malloc failed. **\n");
+				return -1;
+			}
+			indir1_size = blksz;
+		}
+		if ((__le32_to_cpu(inode->b.blocks.indir_block) <<
+		     log2_blksz) != indir1_blkno) {
+			status = ext2fs_devread(__le32_to_cpu(inode->b.blocks.indir_block) << log2_blksz,
+						 0, blksz,
+						(char *) indir1_block);
+			if (status == 0) {
+				puts("** ext2fs read block(indir 1) failed. **\n");
+				return 0;
+			}
+			indir1_blkno =
+				__le32_to_cpu(inode->b.blocks.
+					       indir_block) << log2_blksz;
+		}
+		blknr = __le32_to_cpu(indir1_block
+				       [fileblock - INDIRECT_BLOCKS]);
+	}
+	/* Double indirect.  */
+	else if (fileblock <
+		(INDIRECT_BLOCKS +(blksz / 4 *(blksz / 4 + 1)))) {
+		unsigned int perblock = blksz / 4;
+		unsigned int rblock = fileblock -(INDIRECT_BLOCKS
+						   + blksz / 4);
+
+		if (indir1_block == NULL) {
+			indir1_block =(uint32_t *) malloc(blksz);
+			if (indir1_block == NULL) {
+				puts("** ext2fs read block(indir 2 1) malloc failed. **\n");
+				return -1;
+			}
+			indir1_size = blksz;
+			indir1_blkno = -1;
+		}
+		if (blksz != indir1_size) {
+			free(indir1_block);
+			indir1_block = NULL;
+			indir1_size = 0;
+			indir1_blkno = -1;
+			indir1_block =(uint32_t *) malloc(blksz);
+			if (indir1_block == NULL) {
+				puts("** ext2fs read block(indir 2 1) malloc failed. **\n");
+				return -1;
+			}
+			indir1_size = blksz;
+		}
+		if ((__le32_to_cpu(inode->b.blocks.double_indir_block) <<
+		     log2_blksz) != indir1_blkno) {
+			status = ext2fs_devread(__le32_to_cpu(inode->b.blocks.double_indir_block) << log2_blksz,
+						0, blksz,
+						(char *) indir1_block);
+			if (status == 0) {
+				puts("** ext2fs read block(indir 2 1) failed. **\n");
+				return -1;
+			}
+			indir1_blkno =
+				__le32_to_cpu(inode->b.blocks.double_indir_block) << log2_blksz;
+		}
+
+		if (indir2_block == NULL) {
+			indir2_block =(uint32_t *) malloc(blksz);
+			if (indir2_block == NULL) {
+				puts("** ext2fs read block(indir 2 2) malloc failed. **\n");
+				return -1;
+			}
+			indir2_size = blksz;
+			indir2_blkno = -1;
+		}
+		if (blksz != indir2_size) {
+			free(indir2_block);
+			indir2_block = NULL;
+			indir2_size = 0;
+			indir2_blkno = -1;
+			indir2_block =(uint32_t *) malloc(blksz);
+			if (indir2_block == NULL) {
+				puts("** ext2fs read block(indir 2 2) malloc failed. **\n");
+				return -1;
+			}
+			indir2_size = blksz;
+		}
+		if ((__le32_to_cpu(indir1_block[rblock / perblock]) <<
+		     log2_blksz) != indir1_blkno) {
+			status = ext2fs_devread(__le32_to_cpu(indir1_block[rblock / perblock]) << log2_blksz,
+						 0, blksz,
+						(char *) indir2_block);
+			if (status == 0) {
+				puts("** ext2fs read block(indir 2 2) failed. **\n");
+				return -1;
+			}
+			indir2_blkno =
+				__le32_to_cpu(indir1_block[rblock / perblock]) << log2_blksz;
+		}
+		blknr = __le32_to_cpu(indir2_block[rblock % perblock]);
+	}
+	/* Tripple indirect.  */
+	else {
+		puts("** ext2fs doesn't support tripple indirect blocks. **\n");
+		return -1;
+	}
+#ifdef DEBUG
+	printf("ext2fs_read_block %08x\n", blknr);
+#endif
+	return blknr;
+}
+
+
+int ext2fs_read_file
+	(ext2fs_node_t node, int pos, unsigned int len, char *buf) {
+	int i;
+	int blockcnt;
+	int log2blocksize = LOG2_EXT2_BLOCK_SIZE(node->data);
+	int blocksize = 1 <<(log2blocksize + DISK_SECTOR_BITS);
+	unsigned int filesize = __le32_to_cpu(node->inode.size);
+
+	/* Adjust len so it we can't read past the end of the file.  */
+	if (len > filesize) {
+		len = filesize;
+	}
+	blockcnt = ((len + pos) + blocksize - 1) / blocksize;
+
+	for(i = pos / blocksize; i < blockcnt; i++) {
+		int blknr;
+		int blockoff = pos % blocksize;
+		int blockend = blocksize;
+
+		int skipfirst = 0;
+
+		blknr = ext2fs_read_block(node, i);
+		if (blknr < 0)
+			return -1;
+
+		blknr = blknr << log2blocksize;
+
+		/* Last block.  */
+		if (i == blockcnt - 1) {
+			blockend =(len + pos) % blocksize;
+
+			/* The last portion is exactly blocksize.  */
+			if (!blockend) {
+				blockend = blocksize;
+			}
+		}
+
+		/* First block.  */
+		if (i == pos / blocksize) {
+			skipfirst = blockoff;
+			blockend -= skipfirst;
+		}
+
+		/* If the block number is 0 this block is not stored on disk but
+		   is zero filled instead.  */
+		if (blknr) {
+			int status;
+
+			status = ext2fs_devread(blknr, skipfirst, blockend, buf);
+			if (status == 0)
+				return -1;
+		} else
+			memset(buf, 0, blocksize - skipfirst);
+
+		buf += blocksize - skipfirst;
+	}
+	return(len);
+}
+
+
+static int ext2fs_iterate_dir(ext2fs_node_t dir, char *name, ext2fs_node_t * fnode, int *ftype)
+{
+	unsigned int fpos = 0;
+	int status;
+	struct ext2fs_node *diro =(struct ext2fs_node *) dir;
+
+#ifdef DEBUG
+	if (name != NULL)
+		printf("Iterate dir %s\n", name);
+#endif /* of DEBUG */
+	if (!diro->inode_read) {
+		status = ext2fs_read_inode(diro->data, diro->ino,
+					    &diro->inode);
+		if (status == 0)
+			return(0);
+	}
+	/* Search the file.  */
+	while (fpos < __le32_to_cpu(diro->inode.size)) {
+		struct ext2_dirent dirent;
+
+		status = ext2fs_read_file(diro, fpos,
+					   sizeof(struct ext2_dirent),
+					  (char *) &dirent);
+		if (status < 1)
+			return 0;
+
+		if (dirent.namelen != 0) {
+			char filename[256];
+			ext2fs_node_t fdiro;
+			int type = FILETYPE_UNKNOWN;
+
+			status = ext2fs_read_file(diro,
+						   fpos + sizeof(struct ext2_dirent),
+						   dirent.namelen, filename);
+			if (status < 1)
+				return(0);
+
+			fdiro = malloc(sizeof(struct ext2fs_node));
+			if (!fdiro)
+				return(0);
+
+
+			fdiro->data = diro->data;
+			fdiro->ino = __le32_to_cpu(dirent.inode);
+
+			filename[dirent.namelen] = '\0';
+
+			if (dirent.filetype != FILETYPE_UNKNOWN) {
+				fdiro->inode_read = 0;
+
+				if (dirent.filetype == FILETYPE_DIRECTORY) {
+					type = FILETYPE_DIRECTORY;
+				} else if (dirent.filetype ==
+					   FILETYPE_SYMLINK) {
+					type = FILETYPE_SYMLINK;
+				} else if (dirent.filetype == FILETYPE_REG) {
+					type = FILETYPE_REG;
+				}
+			} else {
+				/* The filetype can not be read from the dirent, get it from inode */
+
+				status = ext2fs_read_inode(diro->data,
+							    __le32_to_cpu(dirent.inode),
+							    &fdiro->inode);
+				if (status == 0) {
+					free(fdiro);
+					return(0);
+				}
+				fdiro->inode_read = 1;
+
+				if ((__le16_to_cpu(fdiro->inode.mode) &
+				     FILETYPE_INO_MASK) ==
+				    FILETYPE_INO_DIRECTORY) {
+					type = FILETYPE_DIRECTORY;
+				} else if ((__le16_to_cpu(fdiro->inode.mode)
+					    & FILETYPE_INO_MASK) ==
+					   FILETYPE_INO_SYMLINK) {
+					type = FILETYPE_SYMLINK;
+				} else if ((__le16_to_cpu(fdiro->inode.mode)
+					    & FILETYPE_INO_MASK) ==
+					   FILETYPE_INO_REG) {
+					type = FILETYPE_REG;
+				}
+			}
+#ifdef DEBUG
+			printf("iterate >%s<\n", filename);
+#endif /* of DEBUG */
+			if ((name != NULL) &&(fnode != NULL)
+			    &&(ftype != NULL)) {
+				if (strcmp(filename, name) == 0) {
+					*ftype = type;
+					*fnode = fdiro;
+					return 1;
+				}
+			} else {
+				if (fdiro->inode_read == 0) {
+					status = ext2fs_read_inode(diro->data,
+							    __le32_to_cpu(dirent.inode),
+							    &fdiro->inode);
+					if (status == 0) {
+						free(fdiro);
+						return(0);
+					}
+					fdiro->inode_read = 1;
+				}
+				switch(type) {
+				case FILETYPE_DIRECTORY:
+					puts("<DIR> ");
+					break;
+				case FILETYPE_SYMLINK:
+					puts("<SYM> ");
+					break;
+				case FILETYPE_REG:
+					puts("      ");
+					break;
+				default:
+					puts("< ? > ");
+					break;
+				}
+				printdec(__le32_to_cpu(fdiro->inode.size));
+				puts("  ");
+				puts(filename);
+				puts("\n");
+			}
+			free(fdiro);
+		}
+		fpos += __le16_to_cpu(dirent.direntlen);
+	}
+	return 0;
+}
+
+
+static char *ext2fs_read_symlink(ext2fs_node_t node) {
+	char *symlink;
+	struct ext2fs_node *diro = node;
+	int status;
+
+	if (!diro->inode_read) {
+		status = ext2fs_read_inode(diro->data, diro->ino,
+					    &diro->inode);
+		if (status == 0) {
+			return(0);
+		}
+	}
+	symlink = malloc(__le32_to_cpu(diro->inode.size) + 1);
+	if (!symlink)
+		return(0);
+
+	/* If the filesize of the symlink is bigger than
+	   60 the symlink is stored in a separate block,
+	   otherwise it is stored in the inode.  */
+	if (__le32_to_cpu(diro->inode.size) <= 60) {
+		strncpy(symlink, diro->inode.b.symlink,
+			 __le32_to_cpu(diro->inode.size));
+	} else {
+		status = ext2fs_read_file(diro, 0,
+					   __le32_to_cpu(diro->inode.size),
+					   symlink);
+		if (status == 0) {
+			free(symlink);
+			return(0);
+		}
+	}
+	symlink[__le32_to_cpu(diro->inode.size)] = '\0';
+	return(symlink);
+}
+
+
+int ext2fs_find_file1
+	(const char *currpath,
+	 ext2fs_node_t currroot, ext2fs_node_t * currfound, int *foundtype) {
+	char fpath[strlen(currpath) + 1];
+	char *name = fpath;
+	char *next;
+	int status;
+	int type = FILETYPE_DIRECTORY;
+	ext2fs_node_t currnode = currroot;
+	ext2fs_node_t oldnode = currroot;
+
+	strncpy(fpath, currpath, strlen(currpath) + 1);
+
+	/* Remove all leading slashes.  */
+	while (*name == '/')
+		name++;
+
+	if (!*name) {
+		*currfound = currnode;
+		return 1;
+	}
+
+	for(;;) {
+		int found;
+
+		/* Extract the actual part from the pathname.  */
+		next = strchr(name, '/');
+		if (next) {
+			/* Remove all leading slashes.  */
+			while (*next == '/') {
+				*(next++) = '\0';
+			}
+		}
+
+		/* At this point it is expected that the current node is a directory, check if this is true.  */
+		if (type != FILETYPE_DIRECTORY) {
+			ext2fs_free_node(currnode, currroot);
+			return(0);
+		}
+
+		oldnode = currnode;
+
+		/* Iterate over the directory.  */
+		found = ext2fs_iterate_dir(currnode, name, &currnode, &type);
+		if (found == 0)
+			return(0);
+
+		if (found == -1)
+			break;
+
+		/* Read in the symlink and follow it.  */
+		if (type == FILETYPE_SYMLINK) {
+			char *symlink;
+
+			/* Test if the symlink does not loop.  */
+			if (++symlinknest == 8) {
+				ext2fs_free_node(currnode, currroot);
+				ext2fs_free_node(oldnode, currroot);
+				return(0);
+			}
+
+			symlink = ext2fs_read_symlink(currnode);
+			ext2fs_free_node(currnode, currroot);
+
+			if (!symlink) {
+				ext2fs_free_node(oldnode, currroot);
+				return(0);
+			}
+#ifdef DEBUG
+			printf("Got symlink >%s<\n", symlink);
+#endif /* of DEBUG */
+			/* The symlink is an absolute path, go back to the root inode.  */
+			if (symlink[0] == '/') {
+				ext2fs_free_node(oldnode, currroot);
+				oldnode = &ext2fs_root->diropen;
+			}
+
+			/* Lookup the node the symlink points to.  */
+			status = ext2fs_find_file1(symlink, oldnode,
+						    &currnode, &type);
+
+			free(symlink);
+
+			if (status == 0) {
+				ext2fs_free_node(oldnode, currroot);
+				return(0);
+			}
+		}
+
+		ext2fs_free_node(oldnode, currroot);
+
+		/* Found the node!  */
+		if (!next || *next == '\0') {
+			*currfound = currnode;
+			*foundtype = type;
+			return(1);
+		}
+		name = next;
+	}
+	return -1;
+}
+
+
+int ext2fs_find_file
+	(const char *path,
+	 ext2fs_node_t rootnode, ext2fs_node_t * foundnode, int expecttype) {
+	int status;
+	int foundtype = FILETYPE_DIRECTORY;
+
+
+	symlinknest = 0;
+	if (!path)
+		return(0);
+
+	status = ext2fs_find_file1(path, rootnode, foundnode, &foundtype);
+	if (status == 0)
+		return 0;
+
+	/* Check if the node that was found was of the expected type.  */
+	if ((expecttype == FILETYPE_REG) &&(foundtype != expecttype)) {
+		return 0;
+	} else if ((expecttype == FILETYPE_DIRECTORY)
+		   &&(foundtype != expecttype)) {
+		return 0;
+	}
+	return 1;
+}
+
+
+int ext2fs_ls(char *dirname) {
+	ext2fs_node_t dirnode;
+	int status;
+
+	if (ext2fs_root == NULL)
+		return 0;
+
+	status = ext2fs_find_file(dirname, &ext2fs_root->diropen, &dirnode,
+				   FILETYPE_DIRECTORY);
+	if (status != 1) {
+		puts("** Can not find directory. **\n");
+		return 1;
+	}
+	ext2fs_iterate_dir(dirnode, NULL, NULL, NULL);
+	ext2fs_free_node(dirnode, &ext2fs_root->diropen);
+	return 0;
+}
+
+
+int ext2fs_open(const char *filename) {
+	ext2fs_node_t fdiro = NULL;
+	int status;
+	int len;
+
+	if (ext2fs_root == NULL)
+		return -1;
+
+	ext2fs_file = NULL;
+	status = ext2fs_find_file(filename, &ext2fs_root->diropen, &fdiro,
+				   FILETYPE_REG);
+	if (status == 0)
+		goto fail;
+
+	if (!fdiro->inode_read) {
+		status = ext2fs_read_inode(fdiro->data, fdiro->ino,
+					    &fdiro->inode);
+		if (status == 0)
+			goto fail;
+	}
+	len = __le32_to_cpu(fdiro->inode.size);
+	ext2fs_file = fdiro;
+	return(len);
+
+fail:
+	ext2fs_free_node(fdiro, &ext2fs_root->diropen);
+	return -1;
+}
+
+
+int ext2fs_close(void
+	) {
+	if ((ext2fs_file != NULL) &&(ext2fs_root != NULL)) {
+		ext2fs_free_node(ext2fs_file, &ext2fs_root->diropen);
+		ext2fs_file = NULL;
+	}
+	if (ext2fs_root != NULL) {
+		free(ext2fs_root);
+		ext2fs_root = NULL;
+	}
+	if (indir1_block != NULL) {
+		free(indir1_block);
+		indir1_block = NULL;
+		indir1_size = 0;
+		indir1_blkno = -1;
+	}
+	if (indir2_block != NULL) {
+		free(indir2_block);
+		indir2_block = NULL;
+		indir2_size = 0;
+		indir2_blkno = -1;
+	}
+	return(0);
+}
+
+
+int ext2fs_read(char *buf, unsigned len) {
+	int status;
+
+	if (ext2fs_root == NULL)
+		return 0;
+
+	if (ext2fs_file == NULL)
+		return 0;
+
+	status = ext2fs_read_file(ext2fs_file, 0, len, buf);
+	return status;
+}
+
+
+int ext2fs_mount(void) {
+	struct ext2_data *data;
+	int status;
+
+	data = malloc(sizeof(struct ext2_data));
+	if (!data)
+		return 0;
+
+	/* Read the superblock.  */
+	status = ext2fs_devread(1 * 2, 0, sizeof(struct ext2_sblock),
+				(char *) &data->sblock);
+	if (!status)
+		goto fail;
+
+	/* Make sure this is an ext2 filesystem.  */
+	if (__le16_to_cpu(data->sblock.magic) != EXT2_MAGIC)
+		goto fail;
+
+	data->diropen.data = data;
+	data->diropen.ino = 2;
+	data->diropen.inode_read = 1;
+	data->inode = &data->diropen.inode;
+
+	status = ext2fs_read_inode(data, 2, data->inode);
+	if (status == 0)
+		goto fail;
+
+	ext2fs_root = data;
+
+	return 1;
+
+fail:
+	puts("Failed to mount ext2 filesystem...\n");
+	free(data);
+	ext2fs_root = NULL;
+
+	return 0;
+}
+