diff --git a/TODO b/TODO
index 36b1e44..d6032e0 100644
--- a/TODO
+++ b/TODO
@@ -10,9 +10,12 @@ FEATURES
 		[ok] Joliet
 		Merge RR and Joliet trees
 		[ok] User options to customize reading
-		Read El-Torito info
+		[ok] Read El-Torito info
 	[ok] Multisession
 		[ok] DVD+RW image growing
+		El-Torito images from previous session
+			Add new el-torito image from prev. session file
+			Path for isolinux from prev. session
 	UDF
 	[ok] ISO relaxed contraints
 	ISO 9660:1998
diff --git a/libisofs/ecma119.c b/libisofs/ecma119.c
index 0af05fd..13956cc 100644
--- a/libisofs/ecma119.c
+++ b/libisofs/ecma119.c
@@ -184,15 +184,9 @@ calc_dir_size(struct ecma119_write_target *t,
 
 	for (i = 0; i < dir->info.dir.nchildren; i++) {
 		struct ecma119_tree_node *ch = dir->info.dir.children[i];
-		//struct iso_tree_node *iso = ch->iso_self;
 		if (ch->type == ECMA119_DIR) {
 			calc_dir_size(t, ch);
-		} 
-//		else if (iso && iso->attrib.st_size
-//			       && iso->loc.type == LIBISO_FILESYS
-//			       && iso->loc.path) {
-//			t->filelist_len++;
-//		}
+		}
 	}
 }
 
@@ -231,12 +225,11 @@ cmp_file(const void *f1, const void *f2)
  * Fill out the block field for each file and fill out t->filelist.
  */
 static void
-calc_file_pos(struct ecma119_write_target *t,
-	      struct ecma119_tree_node *dir)
+calc_file_pos(struct ecma119_write_target *t)
 {
 	size_t i;
 
-	assert(dir->type == ECMA119_DIR);
+	assert(t);
 	
 	t->filelist = calloc(1, sizeof(struct iso_file *) * t->file_table->count);
 
@@ -338,7 +331,17 @@ ecma119_target_new(struct iso_volset *volset,
 	
 	t->catalog = volset->volume[opts->volnum]->bootcat;
 	t->eltorito = t->catalog ? 1 : 0;
+	t->write_eltorito = opts->copy_eltorito;
+	if (t->eltorito && (!t->ms_block || !t->catalog->proc) ) {
+		/* 
+		 * For new and modified images we always need to write el-torito.
+		 * For ms images, if the boot catalog was newly added, we also need
+		 * to write it!
+		 */
+		t->write_eltorito = 1;
+	}
 	
+	/* create the trees */
 	t->root = ecma119_tree_create(t, iso_root);
 	if (t->joliet)
 		t->joliet_root = joliet_tree_create(t, iso_root);
@@ -377,8 +380,8 @@ ecma119_target_new(struct iso_volset *volset,
 
 	t->curblock = t->ms_block /* nwa for ms, usually 0 */
 		+ 16 /* system area */
-		+ 1	/* volume desc */
-		+ 1;	/* volume desc terminator */
+		+ 1	 /* primary volume desc */
+		+ 1; /* volume desc terminator */
 
 	if (t->eltorito)
 		t->curblock += 1; /* boot record volume descriptor */
@@ -411,17 +414,24 @@ ecma119_target_new(struct iso_volset *volset,
 	
 	/* el-torito? */
 	if (t->eltorito) {
-		
-		/* add catalog block */
-		t->catalog->file->block = t->curblock;
-		t->curblock += div_up(2048, t->block_size);
-		el_torito_get_image_files(t);
+		if (t->write_eltorito) {
+			/* add catalog block */
+			t->catblock = t->curblock;
+			t->curblock += div_up(2048, t->block_size);
+	
+			/* add img block */
+			t->imgblock = t->curblock;
+			t->curblock += div_up(t->catalog->image->node->node.attrib.st_size, 
+			                      t->block_size);
+		} else {
+			assert(t->ms_block);
+			assert(t->catalog->proc);
+			t->catblock = t->catalog->node->loc.block;
+			t->imgblock = t->catalog->image->node->loc.block;
+		}
 	}
 	
-	calc_file_pos(t, t->root);
-	
-	if (t->eltorito)
-		el_torito_patch_image_files(t);
+	calc_file_pos(t);
 
 	if (t->rockridge) {
 		susp_finalize(t, t->root);
@@ -438,9 +448,6 @@ ecma119_target_new(struct iso_volset *volset,
 		 */
 		uint8_t *buf;
 		
-		/* set the 32 block buffer to 0 */
-		memset(opts->overwrite, 0, 32 * t->block_size);
-		
 		/* skip the first 16 blocks (system area) */
 		buf = opts->overwrite + 16 * t->block_size;
 		
@@ -494,16 +501,15 @@ is_eltorito_state(enum ecma119_write_state state)
 static void
 next_state(struct ecma119_write_target *t)
 {
+	char msg[42];
 	t->state++;
 	while ( (!t->joliet && is_joliet_state(t->state)) 
-	      ||(!t->eltorito && is_eltorito_state(t->state)) )
+	      ||(!t->eltorito && is_eltorito_state(t->state))
+	      ||(!t->write_eltorito && t->state == ECMA119_WRITE_ELTORITO_CATALOG) )
 		t->state++;
 
-	{
-	char msg[42];
 	sprintf(msg, "Now in state %d, curblock=%d.", t->state, t->curblock);
 	iso_msg_debug(msg);
-	}
 }
 
 static void
@@ -556,13 +562,14 @@ wr_files(struct ecma119_write_target *t, uint8_t *buf)
 		assert( !t->ms_block && t->src );
 		
 		/**
-		 * f->block block where file read begins
+		 * f->block block where file write begins
 		 * t->curblock block we're writting now
 		 * f->real_ino initial block for file on source
 		 */
 		block = t->curblock - f->block;
 		if ( t->src->read_block(t->src, f->real_ino + block, buf) ) {
-			warn("problem reading from previous image");
+			iso_msg_sorry(LIBISO_CANT_READ_IMG, 
+				"Problem reading file from previous image");
 		}
 		if ( f->size <= (off_t) (block+1) * t->block_size ) {
 			f_st->file++;
@@ -581,6 +588,8 @@ wr_files(struct ecma119_write_target *t, uint8_t *buf)
 			f_st->data_len = f->size;
 			f_st->fd = fopen(path, "r");
 			if (!f_st->fd) {
+				//FIXME instead of exit, just print a msg error and
+				//skip file (what about reading from /dev/zero? instead)
 				err(1, "couldn't open %s for reading", path);
 			}
 			assert(t->curblock + t->ms_block == f->block);
@@ -588,10 +597,15 @@ wr_files(struct ecma119_write_target *t, uint8_t *buf)
 	
 		nread = fread(buf, 1, t->block_size, f_st->fd);
 		f_st->pos += t->block_size;
-		if (nread < 0)
-			warn("problem reading from %s", path);
-		else if (nread != t->block_size && f_st->pos < f_st->data_len)
-			warnx("incomplete read from %s", path);
+		if (nread < 0) {
+			char msg[PATH_MAX + 32];
+			sprintf(msg, "Problem reading from %s", path);
+			iso_msg_sorry(LIBISO_CANT_READ_FILE, msg);
+		} else if (nread != t->block_size && f_st->pos < f_st->data_len) {
+			char msg[PATH_MAX + 32];
+			sprintf(msg, "Incomplete read from %s", path);
+			iso_msg_sorry(LIBISO_CANT_READ_FILE, msg);
+		}
 		if (f_st->pos >= f_st->data_len) {
 			fclose(f_st->fd);
 			f_st->fd = 0;
@@ -743,6 +757,16 @@ write_one_dir_record(struct ecma119_write_target *t,
 	} else if (node->type == ECMA119_FILE) {
 		len = node->info.file->size;
 		block = node->info.file->block;
+	} else if (node->type == ECMA119_BOOT) {
+		assert(t->eltorito);
+		if (node->info.boot_img) {
+			block = t->imgblock;
+			len = t->catalog->image->node->node.attrib.st_size;
+		} else {
+			/* we always assume 2048 as catalog len */
+			block = t->catblock;
+			len = 2048;
+		}
 	} else {
 		/* for nodes other than files and dirs, we set both len and block to 0 */
 		len = 0;
@@ -872,11 +896,10 @@ static int
 bs_read(struct burn_source *bs, unsigned char *buf, int size)
 {
 	struct ecma119_write_target *t = (struct ecma119_write_target*)bs->data;
-	if (size != t->block_size) {
-		warnx("you must read data in block-sized chunks (%d bytes)",
-			(int)t->block_size);
-		return 0;
-	} else if (t->curblock >= t->vol_space_size + t->ms_block) {
+	
+	assert(size == t->block_size);
+	
+	if (t->curblock >= t->vol_space_size) {
 		return 0;
 	}
 	if (t->state_data_valid)
diff --git a/libisofs/ecma119.h b/libisofs/ecma119.h
index 99f6208..4d93b87 100644
--- a/libisofs/ecma119.h
+++ b/libisofs/ecma119.h
@@ -65,9 +65,22 @@ struct ecma119_write_target
 	unsigned int iso_level:2;
 	unsigned int eltorito:1;
 	
-	int relaxed_constraints; /**< see ecma119_relaxed_constraints_flag */
+	unsigned int write_eltorito:1;
+		/**<
+		 * In multisession discs, select whether to copy el-torito catalog
+		 * and boot image. Copy is needed for isolinux images, that need to
+		 * be patched. However, it can lead to problems when the image is 
+		 * not present in the iso filesystem, because we can't figure out
+		 * its size. In those cases, we only copy 1 block of data.
+		 * When modifying images, we always need to copy data. Thus, this is 
+		 * always 1 for both new and modified images. 
+		 */
 	
 	struct el_torito_boot_catalog *catalog;
+	uint32_t catblock; /**< location of the boot catalog in the new image */
+	uint32_t imgblock; /**< location of the boot image in the new image */
+	
+	int relaxed_constraints; /**< see ecma119_relaxed_constraints_flag */
 	
 	int replace_mode; /**< Replace ownership and modes of files
 	                  * 
diff --git a/libisofs/ecma119_read.c b/libisofs/ecma119_read.c
index 9dc6375..6379619 100644
--- a/libisofs/ecma119_read.c
+++ b/libisofs/ecma119_read.c
@@ -28,12 +28,128 @@
 #include "volume.h"
 #include "tree.h"
 #include "messages.h"
+#include "eltorito.h"
 
 #define BLOCK_SIZE 2048
 
 static int 
 iso_read_dir(struct iso_read_info *info, struct iso_tree_node_dir *parent, 
              uint32_t block);
+
+static struct el_torito_boot_catalog *
+read_el_torito_boot_catalog(struct iso_read_info *info, uint32_t block)
+{
+	struct el_torito_validation_entry *ve;
+	struct el_torito_default_entry *entry;
+	struct el_torito_boot_catalog *catalog;
+	struct el_torito_boot_image *image;
+	unsigned char buffer[BLOCK_SIZE];
+	
+	if ( info->src->read_block(info->src, block, buffer) < 0 ) {
+		info->error = LIBISOFS_READ_FAILURE;
+		return NULL;
+	}
+	
+	ve = (struct el_torito_validation_entry*)buffer;
+	
+	/* check if it is a valid catalog (TODO: check also the checksum)*/
+	if ( (ve->header_id[0] != 1) || (ve->key_byte1[0] != 0x55) 
+	     || (ve->key_byte2[0] != 0xAA) ) {
+	     	
+		iso_msg_sorry(LIBISO_EL_TORITO_WRONG, "Wrong or damaged El-Torito " 
+	     			  "Catalog.\n El-Torito info will be ignored.");
+    	return NULL;
+	}
+	
+	/* check for a valid platform */
+	if (ve->platform_id[0] != 0) {
+		iso_msg_hint(LIBISO_EL_TORITO_UNHANLED, "Unsupported El-Torito platform.\n"
+			"Only 80x86 si supported. El-Torito info will be ignored.");
+	}
+	
+	/* ok, once we are here we assume it is a valid catalog */
+	catalog = malloc(sizeof(struct el_torito_boot_catalog));
+	image = calloc(1, sizeof(struct el_torito_boot_image));
+	catalog->image = image;
+	catalog->proc = LIBISO_PREVIMG;
+	
+	{
+	/* 
+	 * Create the placeholder.
+	 * Note that this could be modified later if we find a directory entry
+	 * for the catalog in the iso tree.
+	 */
+	struct iso_tree_node_boot *boot;
+	boot = calloc(1, sizeof(struct iso_tree_node_boot));
+	boot->node.refcount = 1;
+	boot->node.attrib.st_mode = S_IFREG | 0777;
+	boot->node.attrib.st_atime = boot->node.attrib.st_mtime 
+		= boot->node.attrib.st_ctime = time(NULL);
+	boot->node.attrib.st_size = 2048;
+	boot->node.type = LIBISO_NODE_BOOT;
+	boot->node.procedence = LIBISO_PREVIMG;
+	boot->node.name = NULL;
+	boot->loc.block = block;
+	catalog->node = boot;
+	}
+	
+	/* parse the default entry */
+	entry = (struct el_torito_default_entry *)(buffer + 32);
+	
+	image->bootable = entry->boot_indicator[0] ? 1 : 0;
+	//FIXME we need a way to handle patch_isolinux in ms images!!!
+	image->isolinux = 0;
+	image->type = entry->boot_media_type[0];
+	image->partition_type = entry->system_type[0];
+	image->load_seg = iso_read_lsb(entry->load_seg, 2);
+	image->load_size = iso_read_lsb(entry->sec_count, 2);
+	
+	{
+	/* 
+	 * Create the placeholder.
+	 * Note that this could be modified later if we find a directory entry
+	 * for the image in the iso tree.
+	 */
+	struct iso_tree_node_boot *boot;
+	boot = calloc(1, sizeof(struct iso_tree_node_boot));
+	boot->node.refcount = 1;
+	boot->node.attrib.st_mode = S_IFREG | 0777;
+	boot->node.attrib.st_atime = boot->node.attrib.st_mtime 
+		= boot->node.attrib.st_ctime = time(NULL);
+	boot->node.attrib.st_size = 2048;
+	boot->node.type = LIBISO_NODE_BOOT;
+	boot->node.procedence = LIBISO_PREVIMG;
+	boot->node.name = NULL;
+	boot->img = 1;
+	boot->loc.block = iso_read_lsb(entry->block, 4);
+	image->node = boot;
+	}
+	
+	//TODO how can we check if there are more entries?
+	
+	return catalog;
+}
+
+static struct el_torito_boot_catalog *
+read_el_torito_vol_desc(struct iso_read_info *info, unsigned char *buf)
+{
+	struct ecma119_boot_rec_vol_desc *vol;
+	
+	vol = (struct ecma119_boot_rec_vol_desc*)buf;
+	
+	/* some sanity checks */
+	if ( strncmp((char*)vol->std_identifier, "CD001", 5)
+	     || vol->vol_desc_version[0] != 1 
+	     || strncmp((char*)vol->boot_sys_id, "EL TORITO SPECIFICATION", 23)) {
+	     	
+	     iso_msg_hint(LIBISO_BOOT_VD_UNHANLED, "Unsupported Boot Vol. Desc.\n"
+	     			  "Only El-Torito Specification, Version 1.0 Volume " 
+	     			  "Descriptors are supported. Ignoring boot info");
+	     return NULL;
+	}
+	
+	return read_el_torito_boot_catalog(info, iso_read_lsb(vol->boot_catalog, 4));
+}
              
 /**
  * This reads the "." directory entry, and set the properties of the
@@ -248,12 +364,22 @@ iso_read_single_directory_record(struct iso_read_info *info,
 		break;
 	case S_IFREG: 
 		{
-		node = calloc(1, sizeof(struct iso_tree_node_file));
-		node->type = LIBISO_NODE_FILE;
-		
-		/* set block with extend */
-		((struct iso_tree_node_file*)node)->loc.block = 
-			iso_read_bb(record->block, 4, NULL);
+		uint32_t block;
+		block = iso_read_bb(record->block, 4, NULL);
+			
+		if (info->bootcat && block == info->bootcat->node->loc.block) {
+			/* it is the boot catalog */
+			node = (struct iso_tree_node*)info->bootcat->node;
+		} else if (info->bootcat && block == info->bootcat->image->node->loc.block) {
+			/* it is the boot image */
+			node = (struct iso_tree_node*)info->bootcat->image->node;
+		} else {
+			/* it is a file */
+			node = calloc(1, sizeof(struct iso_tree_node_file));
+			node->type = LIBISO_NODE_FILE;
+			/* set block with extend */
+			((struct iso_tree_node_file*)node)->loc.block = block;
+		}
 		}
 		break;
 	case S_IFLNK: 
@@ -272,7 +398,7 @@ iso_read_single_directory_record(struct iso_read_info *info,
 	
 	node->name = name;
 	node->attrib = atts;
-	node->refcount = 1;
+	node->refcount++; /* 1 for news, 2 for boot nodes */
 	node->procedence = LIBISO_PREVIMG;
 	
 	iso_tree_add_child(parent, node);
@@ -520,7 +646,6 @@ read_root_susp_entries(struct iso_read_info *info,
 	return 0;
 }
 
-
 static struct iso_volset *
 read_pvm(struct iso_read_info *info, uint32_t block)
 {
@@ -628,6 +753,7 @@ iso_volset_read(struct data_source *src, struct ecma119_read_opts *opts)
 	info.gid = opts->gid;
 	info.mode = opts->mode & ~S_IFMT;
 	info.size = &opts->size;
+	info.bootcat = NULL;
 	root_dir_block = 0;
 	
 	/* read primary volume description */
@@ -642,13 +768,16 @@ iso_volset_read(struct data_source *src, struct ecma119_read_opts *opts)
 	do {
 		if ( info.src->read_block(info.src, block, buffer) < 0 ) {
 			info.error = LIBISOFS_READ_FAILURE;
-	    	iso_volset_free(volset);
-			return NULL;
+			/* cleanup and exit */
+			goto read_cleanup;
 		}
 		switch (buffer[0]) {
 		case 0:
-			/* boot record */
-			//TODO handle el-torito
+			/* 
+			 * This is a boot record 
+			 * Here we handle el-torito
+			 */
+			info.bootcat = read_el_torito_vol_desc(&info, buffer);
 			break;
 		case 2:
 			/* suplementary volume descritor */
@@ -735,11 +864,25 @@ iso_volset_read(struct data_source *src, struct ecma119_read_opts *opts)
 	if ( iso_read_dir(&info, volset->volume[0]->root, root_dir_block) ) {
 	               
 	    /* error, cleanup and return */
-	    iso_volset_free(volset);
-	    return NULL;
+		goto read_cleanup;
 	}
 	
 	// TODO merge tree info
 	
+	/* Add El-Torito info to the volume */
+	if (info.bootcat) {
+		/* ok, add the bootcat to the volume */
+		iso_msg_debug("Found El-Torito bootable volume"); 
+		volset->volume[0]->bootcat = info.bootcat;
+	}
+	
 	return volset;
+	
+read_cleanup:;
+	if (info.bootcat) {
+	    el_torito_boot_catalog_free(info.bootcat);
+	}
+	iso_volset_free(volset);
+	
+	return NULL;
 }
diff --git a/libisofs/ecma119_read.h b/libisofs/ecma119_read.h
index ead19e0..48b416f 100644
--- a/libisofs/ecma119_read.h
+++ b/libisofs/ecma119_read.h
@@ -66,6 +66,9 @@ struct iso_read_info {
 	unsigned int hasJoliet:1; /*< It will be set to 1 if Joliet ext are present,
 	                              to 0 if not. */
 	uint32_t *size; 
+	
+	/* place for el-torito boot catalog */
+	struct el_torito_boot_catalog *bootcat;
 };
 
 
diff --git a/libisofs/ecma119_tree.c b/libisofs/ecma119_tree.c
index e6f890b..e49f6d9 100644
--- a/libisofs/ecma119_tree.c
+++ b/libisofs/ecma119_tree.c
@@ -259,37 +259,29 @@ create_symlink(struct ecma119_write_target *t,
 }
 
 /**
- * Create a new ECMA-119 node representing a boot catalog. This is like a 
- * regular file, but its contents are taken from a El-Torito boot catalog,
- * and not from a file in the local filesystem.
+ * Create a new ECMA-119 node representing a boot catalog or image. 
+ * This will be treated as a normal file when written the directory record, 
+ * but its contents are written in a different way.
  * 
  * See "El Torito" Bootable CD-ROM Format Specification Version 1.0 for
  * more details.
  */
 static struct ecma119_tree_node*
-create_boot_catalog(struct ecma119_write_target *t,
+create_boot(struct ecma119_write_target *t,
 	                struct ecma119_tree_node *parent,
-	                struct iso_tree_node_boot_catalog *iso)
+	                struct iso_tree_node_boot *iso)
 {
 	struct ecma119_tree_node *ret;
-	struct iso_file *file;
 
 	assert(t && iso && parent && parent->type == ECMA119_DIR);
 
-    /* 
-     * This will simply create a ECMA119 file, with the only difference
-     * that the iso_file is not taken from table, but from boot catalog
-     */
-
 	ret = create_ecma119_node(t, parent, (struct iso_tree_node*) iso);
-	ret->type = ECMA119_FILE;
+	ret->type = ECMA119_BOOT;
 	
-	file = iso->catalog->file;
-	file->ino = ++t->ino;
+	ret->info.boot_img = iso->img;
 	
-	ret->attrib.st_nlink = file->nlink;
-	ret->attrib.st_ino = file->ino;
-	ret->info.file = file;
+	ret->attrib.st_nlink = 1;
+	ret->attrib.st_ino =  ++t->ino;
 	return ret;
 }
 
@@ -334,9 +326,8 @@ create_tree(struct ecma119_write_target *t,
 			}
 			}
 			break;
-		case LIBISO_NODE_BOOTCATALOG:
-			ret = create_boot_catalog(t, parent, 
-			                          (struct iso_tree_node_boot_catalog*)iso);
+		case LIBISO_NODE_BOOT:
+			ret = create_boot(t, parent, (struct iso_tree_node_boot*)iso);
 			break;
 		default:
 			/* should never happen */
diff --git a/libisofs/ecma119_tree.h b/libisofs/ecma119_tree.h
index 77ad042..f122310 100644
--- a/libisofs/ecma119_tree.h
+++ b/libisofs/ecma119_tree.h
@@ -21,7 +21,8 @@ enum ecma119_node_type {
 	ECMA119_FILE,
 	ECMA119_SYMLINK,
 	ECMA119_DIR,
-	ECMA119_PLACEHOLDER /**< placeholder for a relocated dir. */
+	ECMA119_PLACEHOLDER, /**< placeholder for a relocated dir. */
+	ECMA119_BOOT
 };
 
 struct ecma119_dir_info {
@@ -72,6 +73,10 @@ struct ecma119_tree_node
 		struct ecma119_tree_node *real_me; /**< this field points to
 					                        *  the relocated directory.
 					                        */
+		unsigned int boot_img:1; /** For boot nodes, it identifies if this
+		                          * corresponds to image(1) or catalog(0).
+		                          * The block is stored in ecma119_write_target
+		                          */
 	} info;
 };
 
diff --git a/libisofs/eltorito.c b/libisofs/eltorito.c
index 8e461f7..9f3f9bd 100644
--- a/libisofs/eltorito.c
+++ b/libisofs/eltorito.c
@@ -3,6 +3,7 @@
 #include "eltorito.h"
 #include "volume.h"
 #include "util.h"
+#include "messages.h"
 
 #include <assert.h>
 #include <malloc.h>
@@ -15,46 +16,6 @@
 #include <fcntl.h>
 
 
-struct el_torito_validation_entry {
-	uint8_t header_id			BP(1, 1);
-	uint8_t platform_id			BP(2, 2);
-	uint8_t reserved			BP(3, 4);
-	uint8_t id_string			BP(5, 28);
-	uint8_t checksum			BP(29, 30);
-	uint8_t key_byte1			BP(31, 31);
-	uint8_t key_byte2			BP(32, 32);
-};
-
-struct el_torito_default_entry {
-	uint8_t boot_indicator		BP(1, 1);
-	uint8_t boot_media_type		BP(2, 2);
-	uint8_t load_seg			BP(3, 4);
-	uint8_t system_type			BP(5, 5);
-	uint8_t unused1				BP(6, 6);
-	uint8_t sec_count			BP(7, 8);
-	uint8_t block				BP(9, 12);
-	uint8_t unused2				BP(13, 32);
-};
-
-struct el_torito_section_header_entry {
-	uint8_t header_indicator	BP(1, 1);
-	uint8_t platform_id			BP(2, 2);
-	uint8_t number				BP(3, 4);
-	uint8_t character			BP(5, 32);
-};
-
-struct el_torito_section_entry {
-	uint8_t boot_indicator		BP(1, 1);
-	uint8_t boot_media_type		BP(2, 2);
-	uint8_t load_seg			BP(3, 4);
-	uint8_t system_type			BP(5, 5);
-	uint8_t unused1				BP(6, 6);
-	uint8_t sec_count			BP(7, 8);
-	uint8_t block				BP(9, 12);
-	uint8_t selec_criteria		BP(13, 13);
-	uint8_t vendor_sc			BP(14, 32);
-};
-
 /**
  * This table should be written with accuracy values at offset
  * 8 of boot image, when used ISOLINUX boot loader
@@ -85,18 +46,67 @@ struct hard_disc_mbr {
 	uint8_t sign2;
 };
 
+static void
+el_torito_image_free(struct el_torito_boot_image *image)
+{
+	assert(image);
+	
+	/* unref image node */
+	iso_tree_free((struct iso_tree_node*)image->node);
+	free(image);
+}
+
+static struct iso_tree_node_boot*
+create_boot_image_node(struct iso_tree_node_file *image)
+{
+	struct iso_tree_node_boot *boot;
+	struct iso_tree_node_dir *parent;
+	
+	assert(image);
+	
+	boot = calloc(1, sizeof(struct iso_tree_node_boot));
+	boot->node.attrib = image->node.attrib;
+	boot->node.type = LIBISO_NODE_BOOT;
+	boot->node.name = strdup(image->node.name);
+	boot->node.hide_flags = image->node.hide_flags;
+	boot->node.refcount = 2; /* mine and tree */
+	boot->loc.path = strdup(image->loc.path);
+	boot->img = 1; /* it refers to image */
+	
+	/* replace iso_tree_node_file with the image */
+	parent = image->node.parent;
+	iso_tree_node_remove(parent, (struct iso_tree_node*)image);
+	iso_tree_add_child(parent, (struct iso_tree_node*) boot);
+	
+	return boot;
+}
+
 static struct el_torito_boot_image *
-create_image(struct iso_tree_node *image, 
+create_image(const char *path, 
              enum eltorito_boot_media_type type)
 {
+	struct stat attrib;
 	struct el_torito_boot_image *boot;
 	int boot_media_type = 0;
 	int load_sectors = 0; /* number of sector to load */
 	unsigned char partition_type = 0;
 	
+	if (stat(path, &attrib)) {
+		iso_msg_sorry(LIBISO_EL_TORITO_WRONG_IMG, "Can't access file.");
+		libisofs_errno = NO_FILE;
+		return NULL;
+	}
+	
+	if ( !S_ISREG(attrib.st_mode) ) {
+		iso_msg_sorry(LIBISO_EL_TORITO_WRONG_IMG, 
+			"We can only create boot images from regular files");
+		libisofs_errno = ELTORITO_WRONG_IMAGE;
+		return NULL;
+	}
+	
 	switch (type) {
 	case ELTORITO_FLOPPY_EMUL:
-		switch (image->attrib.st_size) {
+		switch (attrib.st_size) {
 		case 1200 * 1024:
 			boot_media_type = 1; /* 1.2 meg diskette */
 			break;
@@ -107,10 +117,14 @@ create_image(struct iso_tree_node *image,
 			boot_media_type = 3; /* 2.88 meg diskette */
 			break;
 		default:
-			fprintf(stderr, "Invalid image size %d Kb. Must be one of 1.2, 1.44"
-			               "or 2.88 Mb", (int) image->attrib.st_size / 1024);
+			{
+			char msg[72];
+			sprintf(msg, "Invalid image size %d Kb. Must be one of 1.2, 1.44"
+			               "or 2.88 Mb", (int) attrib.st_size / 1024);
+			iso_msg_sorry(LIBISO_EL_TORITO_WRONG_IMG, msg);
 			libisofs_errno = ELTORITO_WRONG_IMAGE_SIZE;
 			return NULL;
+			}
 			break;	
 		}
 		/* it seems that for floppy emulation we need to load 
@@ -125,13 +139,16 @@ create_image(struct iso_tree_node *image,
 		int used_partition;
 		
 		/* read the MBR on disc and get the type of the partition */
-		fd = open(((struct iso_tree_node_file*)image)->loc.path, O_RDONLY);
+		fd = open(path, O_RDONLY);
 		if ( fd == -1 ) {
-			fprintf(stderr, "Can't open image file\n");
+			iso_msg_sorry(LIBISO_EL_TORITO_WRONG_IMG, "Can't open image file.");
+			libisofs_errno = NO_READ_ACCESS;
 			return NULL;
 		}
 		if ( read(fd, &mbr, sizeof(mbr)) ) {
-			fprintf(stderr, "Can't read MBR from image file\n");
+			iso_msg_sorry(LIBISO_EL_TORITO_WRONG_IMG, 
+			              "Can't read MBR from image file.");
+			libisofs_errno = ELTORITO_WRONG_IMAGE;
 			close(fd);
 			return NULL;
 		}
@@ -139,7 +156,9 @@ create_image(struct iso_tree_node *image,
 		
 		/* check valid MBR signature */
 		if ( mbr.sign1 != 0x55 || mbr.sign2 != 0xAA ) {
-			fprintf(stderr, "Invalid MBR. Wrong signature.\n");
+			iso_msg_sorry(LIBISO_EL_TORITO_WRONG_IMG, 
+			              "Invalid MBR. Wrong signature.");
+			libisofs_errno = ELTORITO_WRONG_IMAGE;
 			return NULL;
 		}
 		
@@ -149,8 +168,11 @@ create_image(struct iso_tree_node *image,
 			if (mbr.partition[i].type != 0) {
 				/* it's an used partition */
 				if (used_partition != -1) {
-					fprintf(stderr, "Invalid MBR. At least 2 partitions: %d and " 
+					char msg[72];
+					sprintf(msg, "Invalid MBR. At least 2 partitions: %d and " 
 									"%d, are being used\n", used_partition, i);
+					iso_msg_sorry(LIBISO_EL_TORITO_WRONG_IMG, msg);
+					libisofs_errno = ELTORITO_WRONG_IMAGE;
 					return NULL;
 				} else
 					used_partition = i;
@@ -170,67 +192,180 @@ create_image(struct iso_tree_node *image,
 	
 	boot = calloc(1, sizeof(struct el_torito_boot_image));
 	boot->bootable = 1;
-	boot->image = (struct iso_tree_node_file *) image;
 	boot->type = boot_media_type;
 	boot->load_size = load_sectors;
 	boot->partition_type = partition_type;
 	return boot;
 }
 
-static struct iso_tree_node_boot_catalog*
+/* parent and name can be null */
+static struct iso_tree_node_boot*
 create_boot_catalog_node(struct iso_tree_node_dir *parent, 
 				         const char *name)
 {
-	struct iso_tree_node_boot_catalog *boot;
+	struct iso_tree_node_boot *boot;
 	
-	assert( parent && name );
+	assert( (parent && name) || (!parent && !name) );
 	
-	boot = calloc(1, sizeof(struct iso_tree_node_boot_catalog));
+	boot = calloc(1, sizeof(struct iso_tree_node_boot));
 	boot->node.attrib.st_mode = S_IFREG | 0444;
 	boot->node.attrib.st_atime = 
 		boot->node.attrib.st_mtime = 
 		boot->node.attrib.st_ctime = time(NULL);
-	boot->node.type = LIBISO_NODE_BOOTCATALOG;
-	boot->node.name = strdup(name);
-	iso_tree_add_child(parent, (struct iso_tree_node*) boot);
+	boot->node.attrib.st_size = 2048;
+	boot->node.type = LIBISO_NODE_BOOT;
+	boot->node.name = name ? strdup(name) : NULL;
+	boot->node.refcount = 1; /* mine */
+	if (parent) {
+		boot->node.refcount++; /* add tree ref */
+		iso_tree_add_child(parent, (struct iso_tree_node*) boot);
+	}
 	return boot;
 }
 
-struct el_torito_boot_image *
-iso_volume_create_boot_catalog(struct iso_volume *volume, 
-                               struct iso_tree_node *image,
-                               enum eltorito_boot_media_type type,
-                               struct iso_tree_node_dir *dir, 
-                               char *name)
+struct el_torito_boot_image*
+iso_volume_set_boot_image(struct iso_volume *volume, 
+                          struct iso_tree_node *image,
+                          enum eltorito_boot_media_type type,
+                          struct iso_tree_node_dir *dir, 
+                          char *name)
 {
 	struct el_torito_boot_image *boot_image;
-	struct iso_tree_node_boot_catalog *boot_node;
+	struct iso_tree_node_boot *cat_node;
 	struct el_torito_boot_catalog *catalog;
+	struct iso_tree_node_file *imgfile;
 	
-	assert( volume && !volume->bootcat);
-	assert( image && ISO_ISREG(image) && dir && name);
+	assert(volume && !volume->bootcat);
+	assert(image && ISO_ISREG(image));
+	assert(dir && name);
 	
-	boot_image = create_image(image, type);
+	imgfile = (struct iso_tree_node_file*)image;
+	
+	if (image->procedence == LIBISO_PREVIMG) {
+		/* FIXME mmm, what to do here? */
+		iso_msg_sorry(LIBISO_EL_TORITO_WRONG_IMG, "Can't use prev. image files "
+			"as boot images");
+		return NULL;
+	}
+	
+	boot_image = create_image(imgfile->loc.path, type);
 	if ( !boot_image ) 
 		return NULL;
+		
+	/* create image node */
+	boot_image->node = create_boot_image_node(imgfile);
 	
 	/* creates the catalog with the given default image */
 	catalog = malloc(sizeof(struct el_torito_boot_catalog));
-	catalog->nentries = 1;
-	catalog->entries = malloc(sizeof(struct el_torito_boot_image *));
-	catalog->entries[0] = boot_image;
-	catalog->file = malloc(sizeof(struct iso_file));
-	catalog->file->size = 2048;
+	if (!catalog) {
+		el_torito_image_free(boot_image);
+		return NULL;
+	}
+	catalog->image = boot_image;
 	
 	/* add catalog file */
-	boot_node = create_boot_catalog_node(dir, name);
-	boot_node->catalog = catalog;
+	cat_node = create_boot_catalog_node(dir, name);
+	catalog->node = cat_node;
 	
 	volume->bootcat = catalog;
 	
 	return boot_image;
 }
 
+struct el_torito_boot_image* 
+iso_volume_set_boot_image_hidden(struct iso_volume *volume, const char* path,
+                                 enum eltorito_boot_media_type type)
+{
+	struct el_torito_boot_image *boot_image;
+	struct iso_tree_node_boot *cat_node;
+	struct el_torito_boot_catalog *catalog;
+	
+	assert(volume && !volume->bootcat);
+	assert(path);
+	
+	boot_image = create_image(path, type);
+	if ( !boot_image ) 
+		return NULL;
+		
+	/* create image node */
+	{
+	struct iso_tree_node_boot *boot;
+	boot = calloc(1, sizeof(struct iso_tree_node_boot));
+	/* we assume the stat won't fail, as we already stat the same file above */
+	stat(path, &boot->node.attrib);
+	boot->node.type = LIBISO_NODE_BOOT;
+	boot->node.refcount = 1; /* mine */
+	boot->loc.path = strdup(path);
+	boot->img = 1; /* it refers to image */
+	boot_image->node = boot;
+	}
+	
+	/* creates the catalog with the given default image */
+	catalog = malloc(sizeof(struct el_torito_boot_catalog));
+	if (!catalog) {
+		el_torito_image_free(boot_image);
+		return NULL;
+	}
+	catalog->image = boot_image;
+	
+	/* add catalog file */
+	cat_node = create_boot_catalog_node(NULL, NULL);
+	catalog->node = cat_node;
+	
+	volume->bootcat = catalog;
+	
+	return boot_image;
+}
+
+struct el_torito_boot_image*
+iso_volume_get_boot_image(struct iso_volume *volume,
+                          struct iso_tree_node **imgnode,
+                          struct iso_tree_node **catnode)
+{
+	struct el_torito_boot_catalog *catalog;
+	
+	assert(volume);
+	
+	catalog = volume->bootcat;
+	if (!catalog)
+		return NULL;
+		
+	if (imgnode)
+		*imgnode = (struct iso_tree_node*)catalog->image->node;
+	
+	if (catnode)
+		*catnode = (struct iso_tree_node*)catalog->node;
+	
+	return catalog->image;
+}
+
+void
+iso_volume_remove_boot_image(struct iso_volume *volume)
+{
+	struct el_torito_boot_catalog *catalog;
+	struct iso_tree_node *catnode;
+	struct iso_tree_node *imgnode;
+	assert(volume);
+	
+	catalog = volume->bootcat;
+	if (!catalog)
+		return;
+	
+	/* remove node from tree */
+	catnode = (struct iso_tree_node*)catalog->node;
+	if (catnode->parent)
+		iso_tree_node_remove(catnode->parent, catnode);
+	
+	/* remove image from tree */
+	imgnode = (struct iso_tree_node*)catalog->image->node;
+	if (imgnode->parent)
+		iso_tree_node_remove(imgnode->parent, imgnode);
+	
+	/* remove catalog */
+	el_torito_boot_catalog_free(catalog);
+	volume->bootcat = NULL;
+}
+
 void
 el_torito_set_load_seg(struct el_torito_boot_image *bootimg, int segment)
 {
@@ -254,43 +389,20 @@ el_torito_set_no_bootable(struct el_torito_boot_image *bootimg)
 }
 
 void
-el_torito_set_write_boot_info(struct el_torito_boot_image *bootimg)
+el_torito_patch_isolinux_image(struct el_torito_boot_image *bootimg)
 {
-	bootimg->patch_isolinux = 1;
+	bootimg->isolinux = 1;
 }
 
 void el_torito_boot_catalog_free(struct el_torito_boot_catalog *cat)
 {
-	size_t i;
-	
 	assert(cat);
 	
-	for(i = 0; i < cat->nentries; ++i) {
-		free(cat->entries[i]);
-	}
-	free(cat->entries);
-	free(cat->file);
+	el_torito_image_free(cat->image);
+	iso_tree_free((struct iso_tree_node*)cat->node);
 	free(cat);
 }
 
-void el_torito_get_image_files(struct ecma119_write_target *t)
-{
-	size_t i;
-	struct el_torito_boot_catalog *cat = t->catalog;
-	assert(cat);
-	
-	for(i = 0; i < cat->nentries; ++i) {
-		
-		struct iso_tree_node_file *image = cat->entries[i]->image;
-		struct iso_file *file = iso_file_table_lookup(t->file_table, image);
-		if ( file == NULL ) {
-			file = iso_file_new(image);
-			iso_file_table_add_file(t->file_table, file);
-		}
-		cat->entries[i]->file = file;
-	}
-}
-
 /**
  * Write the Boot Record Volume Descriptor
  */
@@ -307,7 +419,7 @@ el_torito_write_boot_vol_desc(struct ecma119_write_target *t, uint8_t *buf)
 	memcpy(vol->std_identifier, "CD001", 5);
 	vol->vol_desc_version[0] = 1;
 	memcpy(vol->boot_sys_id, "EL TORITO SPECIFICATION", 23);
-	iso_lsb(vol->boot_catalog, cat->file->block, 4);
+	iso_lsb(vol->boot_catalog, t->catblock, 4);
 }
 
 static void 
@@ -333,104 +445,139 @@ write_validation_entry(struct ecma119_write_target *t, uint8_t *buf)
 }
 
 static void
-patch_boot_file(struct el_torito_boot_image *img)
+patch_boot_image(uint8_t *buf, struct ecma119_write_target *t, ssize_t imgsize)
 {
-	struct boot_info_table info;
-	int fd;
+	struct boot_info_table *info;
 	uint32_t checksum;
-	ssize_t len;
-	uint8_t buf[4];
+	ssize_t offset;
 	
 	memset(&info, 0, sizeof(info));
 	
-	/* open image */
-	fd = open(img->image->loc.path, O_RDWR);
-	if ( fd == -1 ) {
-		//TODO what do do? exit or just continue? 
-		fprintf(stderr, "Can't patch boot image %s\n", img->image->loc.path);
-		close(fd);
-		return;
-	}
-	
 	/* compute checksum, as the the sum of all 32 bit words in boot image
 	 * from offset 64 */
 	checksum = 0;
-	lseek(fd, (off_t) 64, SEEK_SET);
+	offset = (ssize_t) 64;
 	
-	//TODO this can (must) be optimizied by reading to a longer buffer
-	while ( (len = read(fd, buf, 4) ) == 4 ) {
-		checksum += iso_read_lsb(buf, 4);
+	while (offset < imgsize) {
+		checksum += iso_read_lsb(buf + offset, 4);
+		offset += 4;
 	}
-	if ( len != 0 ) {
-		/* error reading file, or file length not multiple of 4 */
-		//TODO what do do? exit or just continue? 
-		fprintf(stderr, "Can't patch boot image %s\n", img->image->loc.path);
-		close(fd);
-		return;
+	if (offset != imgsize) {
+		/* file length not multiple of 4 */
+		iso_msg_warn(LIBISO_ISOLINUX_CANT_PATCH, 
+			"Unexpected isolinux image length. Patch might not work.");
 	}
 	
-	/* fill boot info table */
-	iso_lsb(info.bi_pvd, 16, 4); //FIXME this should be changed when we implement ms
-	iso_lsb(info.bi_file, img->file->block, 4);
-	iso_lsb(info.bi_length, img->image->node.attrib.st_size, 4);
-	iso_lsb(info.bi_csum, checksum, 4);
-	
-	/* patch file */
-	lseek(fd, (off_t) 8, SEEK_SET);
-	write(fd, &info, sizeof(info));
-	
-	close(fd);
-} 
+	/* patch boot info table */
+	info = (struct boot_info_table*)(buf + 8);
+	memset(info, 0, sizeof(struct boot_info_table));
+	iso_lsb(info->bi_pvd, t->ms_block + 16, 4);
+	iso_lsb(info->bi_file, t->imgblock, 4);
+	iso_lsb(info->bi_length, imgsize, 4);
+	iso_lsb(info->bi_csum, checksum, 4);
+}
 
-void 
-el_torito_patch_image_files(struct ecma119_write_target *t)
+static void
+write_boot_image(uint8_t *buf, struct ecma119_write_target *t)
 {
-	size_t i;
-	struct el_torito_boot_catalog *cat = t->catalog;
-	assert(cat);
+	ssize_t imgsize;
+	struct el_torito_boot_image *image;
 	
-	for (i = 0; i < cat->nentries; ++i) {
-		struct el_torito_boot_image *img = cat->entries[i];
-		if ( img->patch_isolinux )
-			patch_boot_file(img);
+	image = t->catalog->image;
+	imgsize= image->node->node.attrib.st_size;
+	
+	/* copy image contents to memory buffer */
+	if (image->node->node.procedence == LIBISO_PREVIMG) {
+		int block, nblocks;
+		uint8_t *memloc;
+		assert(t->src);
+		
+		block = 0;
+		memloc = buf;
+		nblocks = imgsize ? div_up(imgsize, 2048) : 1;
+		while (block < nblocks) {
+			if (t->src->read_block(t->src, 
+			            image->node->loc.block + block, memloc)) {
+				iso_msg_sorry(LIBISO_CANT_READ_IMG,
+					"Unable to read boot image from previous image.");
+				break; /* exit loop */
+			}
+			memloc += 2048;
+			++block;
+		}
+	} else {
+		int fd;
+		ssize_t nread, tread;
+		uint8_t *memloc;
+		const char *path = image->node->loc.path;
+		memloc = buf;
+	
+		fd = open(path, O_RDONLY);
+		if (fd == -1) {
+			iso_msg_sorry(LIBISO_CANT_READ_FILE, 
+			       "Can't open boot image file for reading. Skipping");
+			return;
+		}
+		
+		tread = 0;
+		while (tread < imgsize) {
+			nread = read(fd, memloc, t->block_size);
+			if (nread <= 0) {
+				iso_msg_sorry(LIBISO_CANT_READ_FILE, 
+			       "Problem reading boot image file. Skipping");
+				break; /* exit loop */
+			}
+			tread += nread;
+			memloc += nread;
+		}
+		close(fd);
+	}
+	
+	if (image->isolinux) {
+		/* we need to patch the image */
+		patch_boot_image(buf, t, imgsize);
 	}
 }
 
 /**
  * Write one section entry.
- * Currently this is used for both default and other entries since we
- * put selection criteria no 0 (no sel. criteria)
+ * Currently this is used only for default image (the only supported just now)
  */
 static void
-write_section_entry(uint8_t *buf, struct el_torito_boot_image *img)
+write_section_entry(uint8_t *buf, struct ecma119_write_target *t)
 {
+	struct el_torito_boot_image *img;
 	struct el_torito_section_entry *se = 
 		(struct el_torito_section_entry*)buf;
+		
+	img = t->catalog->image;
+	
+	assert(img);
 
 	se->boot_indicator[0] = img->bootable ? 0x88 : 0x00;
 	se->boot_media_type[0] = img->type;
 	iso_lsb(se->load_seg, img->load_seg, 2);
-	se->system_type[0] = 0; //TODO need to get the partition type
+	se->system_type[0] = img->partition_type;
 	iso_lsb(se->sec_count, img->load_size, 2);
-	iso_lsb(se->block, img->file->block, 4);
+	iso_lsb(se->block, t->imgblock, 4);
 }
 
 /**
- * Write El-Torito Boot Catalog
+ * Write El-Torito Boot Catalog plus image
  */
 static void
 write_catalog(struct ecma119_write_target *t, uint8_t *buf)
 {
 	struct el_torito_boot_catalog *cat = t->catalog;
 	assert(cat);
-	assert(cat->nentries >= 1 && cat->nentries < 63);
+	assert(cat->image);
 	
 	write_validation_entry(t, buf);
 	
 	/* write default entry */
-	write_section_entry(buf + 32, cat->entries[0]);
+	write_section_entry(buf + 32, t);
 
-	//TODO write all images	
+	write_boot_image(buf + 2048, t);
 }
 
 void
@@ -446,9 +593,27 @@ el_torito_wr_boot_vol_desc(struct ecma119_write_target *t, uint8_t *buf)
 void
 el_torito_wr_catalog(struct ecma119_write_target *t, uint8_t *buf)
 {
+	off_t size;
+	off_t imgsize;
 	assert(t->catalog);
+	
+	/*
+	 * Note that when this is called, we need to write el-torito info to
+	 * image. Note, however, that the image could come from a previous session
+	 * and maybe we don't know its size
+	 */
+	
+	imgsize = t->catalog->image->node->node.attrib.st_size;
+	if (imgsize == 0) {
+		iso_msg_warn(LIBISO_EL_TORITO_BLIND_COPY,
+			"Can get boot image size, only one block will be copied");
+		imgsize = 2048;
+	}
+	
+	size = 2048 + div_up(imgsize, t->block_size);
+	
 	ecma119_start_chunking(t,
 			       write_catalog,
-			       2048,
+			       size,
 			       buf);
 }
diff --git a/libisofs/eltorito.h b/libisofs/eltorito.h
index 0b9c91b..54c7adc 100644
--- a/libisofs/eltorito.h
+++ b/libisofs/eltorito.h
@@ -5,52 +5,66 @@
 #include "file.h"
 #include "ecma119.h"
 
-/**
- * Location of the boot catalog
- */
-struct iso_tree_node_boot_catalog
-{
-	struct iso_tree_node node;
-	struct el_torito_boot_catalog *catalog;
-};
-
 struct el_torito_boot_catalog {
-	int nentries;
-	struct el_torito_boot_image **entries;
-	struct iso_file *file; /**< The catalog file */
+	struct iso_tree_node_boot *node; /* node of the catalog */
+	struct el_torito_boot_image *image; /* default boot image */
+	enum tree_node_from proc; /* whether the catalog is new or read from a 
+	                           * prev session/image */
 };
 
 struct el_torito_boot_image {
-	unsigned char bootable; /**< If the entry is bootable. */
-	unsigned char patch_isolinux; /**< If the image will be patched */
+	struct iso_tree_node_boot *node;
+
+	unsigned int bootable:1; /**< If the entry is bootable. */
+	unsigned int isolinux:1; /**< If the image will be patched */
 	unsigned char type; /**< The type of image */
 	unsigned char partition_type; /**< type of partition for HD-emul images */
 	short load_seg; /**< Load segment for the initial boot image. */
 	short load_size; /**< Number of sector to load. */
-	struct iso_tree_node_file *image;
-	struct iso_file *file; 
 };
 
-/*struct el_torito_boot_entry *
-el_torito_add_boot_entry(struct el_torito_boot_catalog *cat, 
-                         struct iso_tree_node_file *image);
-*/
+struct el_torito_validation_entry {
+	uint8_t header_id			BP(1, 1);
+	uint8_t platform_id			BP(2, 2);
+	uint8_t reserved			BP(3, 4);
+	uint8_t id_string			BP(5, 28);
+	uint8_t checksum			BP(29, 30);
+	uint8_t key_byte1			BP(31, 31);
+	uint8_t key_byte2			BP(32, 32);
+};
+
+struct el_torito_default_entry {
+	uint8_t boot_indicator		BP(1, 1);
+	uint8_t boot_media_type		BP(2, 2);
+	uint8_t load_seg			BP(3, 4);
+	uint8_t system_type			BP(5, 5);
+	uint8_t unused1				BP(6, 6);
+	uint8_t sec_count			BP(7, 8);
+	uint8_t block				BP(9, 12);
+	uint8_t unused2				BP(13, 32);
+};
+
+struct el_torito_section_header_entry {
+	uint8_t header_indicator	BP(1, 1);
+	uint8_t platform_id			BP(2, 2);
+	uint8_t number				BP(3, 4);
+	uint8_t character			BP(5, 32);
+};
+
+struct el_torito_section_entry {
+	uint8_t boot_indicator		BP(1, 1);
+	uint8_t boot_media_type		BP(2, 2);
+	uint8_t load_seg			BP(3, 4);
+	uint8_t system_type			BP(5, 5);
+	uint8_t unused1				BP(6, 6);
+	uint8_t sec_count			BP(7, 8);
+	uint8_t block				BP(9, 12);
+	uint8_t selec_criteria		BP(13, 13);
+	uint8_t vendor_sc			BP(14, 32);
+};
 
 void el_torito_boot_catalog_free(struct el_torito_boot_catalog *cat);
 
-/**
- * For each boot image file, this gets the related iso_file object.
- * In most cases, the file is already in the hash table. However, if the
- * boot record is hidden in both ISO/RR and joliet trees, this ensures
- * that boot images will be written to image.
- */
-void el_torito_get_image_files(struct ecma119_write_target *t);
-
-/**
- * Patch image files if selected. This is needed for isolinux boot images 
- */
-void el_torito_patch_image_files(struct ecma119_write_target *t);
-
 /**
  * Write the Boot Record Volume Descriptor
  */
@@ -60,6 +74,9 @@ el_torito_write_boot_vol_desc(struct ecma119_write_target *t, uint8_t *buf);
 void
 el_torito_wr_boot_vol_desc(struct ecma119_write_target *t, uint8_t *buf);
 
+/**
+ * Write catalog + image
+ */
 void
 el_torito_wr_catalog(struct ecma119_write_target *t, uint8_t *buf);
 
diff --git a/libisofs/joliet.c b/libisofs/joliet.c
index ad8583b..dda2579 100644
--- a/libisofs/joliet.c
+++ b/libisofs/joliet.c
@@ -8,6 +8,7 @@
 #include "util.h"
 #include "volume.h"
 #include "eltorito.h"
+#include "messages.h"
 
 #include <assert.h>
 #include <string.h>
@@ -40,14 +41,14 @@ create_node(struct ecma119_write_target *t,
 		}
 		ret->info.file = file;
 		ret->type = JOLIET_FILE;
-	} else {
+	} else if (ISO_ISBOOT(iso)) {
 		/* it's boot catalog info */
-		struct iso_tree_node_boot_catalog *iso_b = 
-		    (struct iso_tree_node_boot_catalog *) iso;
-		struct iso_file *file;
-		file = iso_b->catalog->file;
-		ret->info.file = file;
-		ret->type = JOLIET_FILE;
+		struct iso_tree_node_boot *boot = (struct iso_tree_node_boot*) iso;
+		ret->info.boot_img = boot->img;
+		ret->type = JOLIET_BOOT;
+	} else {
+		/* this should never happen */
+		assert(0);
 	}
 	
 	return ret;
@@ -66,7 +67,7 @@ create_tree(struct ecma119_write_target *t,
 	
 	switch (iso->type) {
 		case LIBISO_NODE_FILE:
-		case LIBISO_NODE_BOOTCATALOG:
+		case LIBISO_NODE_BOOT:
 			root = create_node(t, parent, iso);
 			break;
 		case LIBISO_NODE_DIR:
@@ -85,9 +86,13 @@ create_tree(struct ecma119_write_target *t,
 			}
 			break;
 		default:
-			//TODO replace this printf
-			printf("Can't add this kind of node to a Joliet tree");
+			{
+			char msg[512];
+			sprintf(msg, "Can't add %s to Joliet tree. This kind of files "
+				"can only be added to a Rock Ridget tree. Skipping", iso->name);
+			iso_msg_note(LIBISO_JOLIET_WRONG_FILE_TYPE, msg);
 			return NULL;
+			}
 			break;
 	}
 	return root;
@@ -271,8 +276,19 @@ write_one_dir_record(struct ecma119_write_target *t,
 	if (node->type == JOLIET_DIR) {
 		len = node->info.dir.len;
 		block = node->info.dir.block;
+	} else if (node->type == JOLIET_BOOT) {
+		assert(t->eltorito);
+		if (node->info.boot_img) {
+			block = t->imgblock;
+			len = t->catalog->image->node->node.attrib.st_size;
+		} else {
+			/* we always assume 2048 as catalog len */
+			block = t->catblock;
+			len = 2048;
+		}
 	} else {
 		/* file */
+		assert(node->type == JOLIET_FILE);
 		len = node->info.file->size;
 		block = node->info.file->block;
 	}
diff --git a/libisofs/joliet.h b/libisofs/joliet.h
index 1b4adc4..0930ac2 100644
--- a/libisofs/joliet.h
+++ b/libisofs/joliet.h
@@ -19,7 +19,8 @@ struct iso_tree_node;
 
 enum joliet_node_type {
 	JOLIET_FILE,
-	JOLIET_DIR
+	JOLIET_DIR,
+	JOLIET_BOOT
 };
 
 struct joliet_dir_info {
@@ -41,6 +42,10 @@ struct joliet_tree_node
 	union {
 		struct iso_file *file;
 		struct joliet_dir_info dir;
+		unsigned int boot_img:1; /** For boot nodes, it identifies if this
+		                          * corresponds to image(1) or catalog(0).
+		                          * The block is stored in ecma119_write_target
+		                          */
 	} info;
 };
 
diff --git a/libisofs/libdax_msgs.h b/libisofs/libdax_msgs.h
index 0d532bb..77d0d9f 100644
--- a/libisofs/libdax_msgs.h
+++ b/libisofs/libdax_msgs.h
@@ -382,17 +382,35 @@ Range "scdbackup"          :  0x00020000 to 0x0002ffff
 ------------------------------------------------------------------------------
 Range "vreixo"              :  0x00030000 to 0x0003ffff
 
+ General:
+ 0x00031001 (SORRY,HIGH)    = Can't read file (ignored)
+ 0x00031002 (FATAL,HIGH)    = Can't read file (operation canceled)
+
  Image reading:
  0x00031000 (FATAL,HIGH)    = Unsupported ISO-9660 image
  0x00031001 (HINT,MEDIUM)   = Unsupported Vol Desc that will be ignored
  0x00031002 (FATAL,HIGH)    = Damaged ISO-9660 image
+ 0x00031003 (SORRY,HIGH)    = Can't read previous image file
  
+ Rock-Ridge:
  0x00030101 (HINT,MEDIUM)   = Unsupported SUSP entry that will be ignored
  0x00030102 (SORRY,HIGH)    = Wrong/damaged SUSP entry
  0x00030103 (WARNING,MEDIUM)= Multiple SUSP ER entries where found
  0x00030111 (SORRY,HIGH)    = Unsupported RR feature
  0x00030112 (SORRY,HIGH)    = Error in a Rock Ridge entry
  
+ El-Torito:
+ 0x00030201 (HINT,MEDIUM)   = Unsupported Boot Vol Desc that will be ignored
+ 0x00030202 (SORRY,HIGH)    = Wrong El-Torito catalog
+ 0x00030203 (HINT,MEDIUM)   = Unsupported El-Torito feature
+ 0x00030204 (SORRY,HIGH)    = Invalid file to be an El-Torito image
+ 0x00030205 (WARNING,MEDIUM)= Can't properly patch isolinux image
+ 0x00030206 (WARNING,MEDIUM)= Copying El-Torito from a previous image without
+                              enought info about it
+ 
+ Joliet:
+ 0x00030301 (NOTE,MEDIUM)   = Unsupported file type for Joliet tree
+ 
  
 ------------------------------------------------------------------------------
 
diff --git a/libisofs/libisofs.h b/libisofs/libisofs.h
index 84cc67b..85a64a1 100644
--- a/libisofs/libisofs.h
+++ b/libisofs/libisofs.h
@@ -64,7 +64,7 @@ enum iso_tree_node_type {
 	LIBISO_NODE_DIR,
 	LIBISO_NODE_FILE,
 	LIBISO_NODE_SYMLINK,
-	LIBISO_NODE_BOOTCATALOG
+	LIBISO_NODE_BOOT
 };
 
 #define LIBISO_ISDIR(n) (iso_tree_node_get_type(n) == LIBISO_NODE_DIR)
@@ -89,13 +89,12 @@ struct iso_tree_node_file;
 struct iso_tree_node_symlink;
 
 /**
- * A node that represents a boot catalog
- * FIXME I'm not very sure how this should be treated.
+ * A node that represents an El-Torito file.
  */
-struct iso_tree_node_boot_catalog;
+struct iso_tree_node_boot;
 
 /**
- * El-Torito boot image
+ * Information about El-Torito boot image.
  * \see eltorito.h
  */
 struct el_torito_boot_image;
@@ -213,6 +212,16 @@ struct ecma119_source_opts {
 	int level;  /**< ISO level to write at. */
 	int flags;  /**< Which extensions to support. */
 	int relaxed_constraints; /**< see ecma119_relaxed_constraints_flag */
+	
+	unsigned int copy_eltorito:1;
+		/**<
+		 * In multisession discs, select whether to copy el-torito catalog
+		 * and boot image. Copy is needed for isolinux images, that need to
+		 * be patched. However, it can lead to problems when the image is 
+		 * not present in the iso filesystem, because we can't figure out
+		 * its size. In those cases, we only copy 1 block of data.
+		 */
+	
 	unsigned int no_cache_inodes:1; 
 	            /**< If use inode caching or not. Set it to 1 to prevent
 	             *   inode caching.
@@ -283,6 +292,9 @@ struct ecma119_source_opts {
 				 * 64KiB, where libisofs will write the contents that should 
 				 * be written at the beginning of a overwriteable media, to
 				 * grow the image.
+				 * You shoudl initialize the buffer either with 0s, or with
+				 * the contents of the first blocks of the image you're
+				 * growing. In most cases, 0 is good enought.
 				 */
 };
 
@@ -386,6 +398,8 @@ int libisofs_errno;
 #define UNEXPECTED_FILE_TYPE 3
 /* invalid boot image size */
 #define ELTORITO_WRONG_IMAGE_SIZE 4
+/* invalid image */
+#define ELTORITO_WRONG_IMAGE 5
 
 /**
  * Controls the bahavior of iso_tree_radd_dir function
@@ -553,6 +567,10 @@ const char *iso_volume_get_biblio_file_id(struct iso_volume *volume);
 /**
  * Create a bootable volume by adding a El-Torito boot image.
  * 
+ * This also add a catalog tree node to the image filesystem tree. The tree
+ * node for the image will be replaced with a iso_tree_node_boot node, that
+ * acts as a placeholder for the real image.
+ * 
  * \param volume The volume to make bootable.
  * \param image The tree node with the file to use as default boot image.
  * \param type The boot media type. This can be one of 3 types:
@@ -573,16 +591,60 @@ const char *iso_volume_get_biblio_file_id(struct iso_volume *volume);
  * 
  * \pre \p volume is a volume without any boot catalog yet
  * \pre \p image is a file tree node already inserted in the volume tree.
+ * \pre \p image is a file tree node that refers to a newly added file, not
+ *         one from a previous session. FIXME allow prev session files too
  * \pre \p dir is a directory node already inserted in the volume tree.
  * \pre \p name There isn't any dir child with the same name.
  * 
  */
-struct el_torito_boot_image *
-iso_volume_create_boot_catalog(struct iso_volume *volume, 
-                               struct iso_tree_node *image,
-                               enum eltorito_boot_media_type type,
-                               struct iso_tree_node_dir *dir, 
-                               char *name);
+struct el_torito_boot_image*
+iso_volume_set_boot_image(struct iso_volume *volume, 
+                          struct iso_tree_node *image,
+                          enum eltorito_boot_media_type type,
+                          struct iso_tree_node_dir *dir, 
+                          char *name);
+
+struct el_torito_boot_image* 
+iso_volume_set_boot_image_hidden(struct iso_volume *volume, 
+                                 const char* path,
+                                 enum eltorito_boot_media_type type);
+
+/**
+ * Get El-Torito boot image of the volume, if any.
+ * 
+ * This can be useful, for example, to check if a volume read from a previous
+ * session or an existing image is bootable. It can also be useful to get
+ * the image and catalog tree nodes. An application would want those, for 
+ * example, to prevent the user removing it.
+ * 
+ * Both tree nodes are owned by libisofs and should not be freed. You can check
+ * if the node is already on the tree by getting its parent (note that when
+ * reading El-Torito info from a previous image, the nodes might not be on
+ * the tree even if you haven't removed them). Remember that you'll need to
+ * get a new ref (with iso_tree_node_ref()) before inserting them again to the
+ * tree, and probably you will also need to set the name or permissions.
+ * 
+ * \param imgnode When not NULL, it will be filled with the image tree node, if
+ *                any.
+ * \param catnode When not NULL, it will be filled with the catalog tree node, 
+ *                if any.
+ * 
+ * \return The default El-Torito bootable image, or NULL is the volume is not
+ *         bootable.
+ */
+struct el_torito_boot_image*
+iso_volume_get_boot_image(struct iso_volume *volume,
+                            struct iso_tree_node **imgnode,
+                            struct iso_tree_node **catnode);
+
+/**
+ * Removes the El-Torito bootable image. Both the catalog and image tree nodes 
+ * are also removed from the image filesystem tree, if there.
+ * If the volume is not bootable (don't have el-torito image) this function is
+ * a nop.
+ */
+void
+iso_volume_remove_boot_image(struct iso_volume *volume);
 
 /**
  * Sets the load segment for the initial boot image. This is only for
@@ -608,12 +670,11 @@ el_torito_set_no_bootable(struct el_torito_boot_image *bootimg);
 /**
  * Specifies that this image needs to be patched. This involves the writting
  * of a 56 bytes boot information table at offset 8 of the boot image file.
- * Be aware that libisofs will modify original boot image file, so do a backup
- * if needed.
+ * The original boot image file won't be modified.
  * This is needed for isolinux boot images.
  */
 void
-el_torito_set_write_boot_info(struct el_torito_boot_image *bootimg);
+el_torito_patch_isolinux_image(struct el_torito_boot_image *bootimg);
 
 /**
  * Locate a node by its path on disc.
diff --git a/libisofs/messages.c b/libisofs/messages.c
index 03ecf2d..93b0514 100644
--- a/libisofs/messages.c
+++ b/libisofs/messages.c
@@ -29,6 +29,13 @@ void iso_msg_debug(char *msg_text)
                        msg_text, 0, 0);
 }
 
+void iso_msg_note(int error_code, char *msg_text)
+{
+	libdax_msgs_submit(libdax_messenger, -1, error_code,
+                       LIBDAX_MSGS_SEV_NOTE, LIBDAX_MSGS_PRIO_MEDIUM, 
+                       msg_text, 0, 0);
+}
+
 void iso_msg_hint(int error_code, char *msg_text)
 {
 	libdax_msgs_submit(libdax_messenger, -1, error_code,
diff --git a/libisofs/messages.h b/libisofs/messages.h
index 53dfebe..1359b08 100644
--- a/libisofs/messages.h
+++ b/libisofs/messages.h
@@ -7,12 +7,19 @@
 
 #include "libdax_msgs.h"
 
+/** Can't read file (ignored) */
+#define LIBISO_CANT_READ_FILE		0x00031001
+/** Can't read file (operation canceled) */
+#define LIBISO_FILE_READ_ERROR		0x00031002
+
 /** Unsupported image feature */
 #define LIBISO_IMG_UNSUPPORTED		0x00031000
 /** Unsupported Vol Desc that will be ignored */
 #define LIBISO_UNSUPPORTED_VD		0x00031001
 /** damaged image */
 #define LIBISO_WRONG_IMG			0x00031002
+/** Can't read previous image file */
+#define LIBISO_CANT_READ_IMG		0x00031003
 
 /* Unsupported SUSP entry */ 
 #define LIBISO_SUSP_UNHANLED		0x00030101
@@ -25,8 +32,26 @@
 /** Error in a Rock Ridge entry. */
 #define LIBISO_RR_ERROR				0x00030112
 
+/** Unsupported boot vol desc. */
+#define LIBISO_BOOT_VD_UNHANLED			0x00030201
+/** Wrong or damaged el-torito catalog */
+#define LIBISO_EL_TORITO_WRONG			0x00030202
+/** Unsupproted el-torito feature */
+#define LIBISO_EL_TORITO_UNHANLED		0x00030203
+/** Trying to add an invalid file as a El-Torito image */
+#define LIBISO_EL_TORITO_WRONG_IMG		0x00030204
+/** Can't properly patch isolinux image */
+#define LIBISO_ISOLINUX_CANT_PATCH		0x00030205
+/** Copying El-Torito from a previous image without enought info about it */
+#define LIBISO_EL_TORITO_BLIND_COPY		0x00030206
+
+/** Unsupported file type for Joliet tree */
+#define LIBISO_JOLIET_WRONG_FILE_TYPE	0x00030301
+
 void iso_msg_debug(char *msg_text);
 
+void iso_msg_note(int error_code, char *msg_text);
+
 void iso_msg_hint(int error_code, char *msg_text);
 
 void iso_msg_warn(int error_code, char *msg_text);
diff --git a/libisofs/tree.c b/libisofs/tree.c
index 044961e..7159dbf 100644
--- a/libisofs/tree.c
+++ b/libisofs/tree.c
@@ -469,6 +469,8 @@ iso_tree_node_ref(struct iso_tree_node *node)
 void
 iso_tree_free(struct iso_tree_node *root)
 {	
+	if (!root)
+		return;
 	if (--root->refcount < 1) {
 		if ( ISO_ISDIR(root) ) {
 			size_t i;
@@ -487,6 +489,11 @@ iso_tree_free(struct iso_tree_node *root)
 			file = (struct iso_tree_node_file *) root;
 			if (root->procedence == LIBISO_NEW)
 				free(file->loc.path);
+		} else if ( ISO_ISBOOT(root) ) {
+			struct iso_tree_node_boot *boot;
+			boot = (struct iso_tree_node_boot *) root;
+			if (root->procedence == LIBISO_NEW && boot->img)
+				free(boot->loc.path);
 		}
 		free(root->name);
 		free(root);
diff --git a/libisofs/tree.h b/libisofs/tree.h
index 7816726..ae42664 100644
--- a/libisofs/tree.h
+++ b/libisofs/tree.h
@@ -95,6 +95,20 @@ struct iso_tree_node_dir
 	struct iso_tree_node **children;
 };
 
+/**
+ * Tree node that corresponds to some El-Torito artifact.
+ * This can be either the boot catalog or a bootable image.
+ */
+struct iso_tree_node_boot
+{
+	struct iso_tree_node node;
+	unsigned int img:1; /*< 1 if img, 0 if catalog */
+	union {
+		char *path; /**< the path of the file on local filesystem */
+		uint32_t block; /**< If the file is from a previous session.*/
+	} loc;
+};
+
 /**
  * An iterator for directory children.
  */
@@ -151,5 +165,6 @@ void iso_tree_print_verbose(const struct iso_tree_node *root,
 #define ISO_ISDIR(n) (n->type == LIBISO_NODE_DIR)
 #define ISO_ISREG(n) (n->type == LIBISO_NODE_FILE)
 #define ISO_ISLNK(n) (n->type == LIBISO_NODE_SYMLINK)
+#define ISO_ISBOOT(n) (n->type == LIBISO_NODE_BOOT)
 
 #endif /* LIBISO_TREE_H */
diff --git a/test/iso.c b/test/iso.c
index 08c0589..fba9d6b 100644
--- a/test/iso.c
+++ b/test/iso.c
@@ -119,10 +119,14 @@ int main(int argc, char **argv)
 		if (!img) {
 			err(1, "boot image patch is not valid");
 		} 
-		bootimg = iso_volume_create_boot_catalog(volume, img, ELTORITO_NO_EMUL, 
+		bootimg = iso_volume_set_boot_image(volume, img, ELTORITO_NO_EMUL, 
 		                                         boot, "boot.cat");
 		el_torito_set_load_size(bootimg, 4);
-		el_torito_set_write_boot_info(bootimg);
+		el_torito_patch_isolinux_image(bootimg);
+		
+		/* Or just this for hidden img
+		 * iso_volume_set_boot_image_hidden(volume, boot_img, ELTORITO_NO_EMUL);
+		 */
 	}
 	
 	volset = iso_volset_new( volume, "VOLSETID" );
@@ -138,8 +142,8 @@ int main(int argc, char **argv)
 	memset(&opts, 0, sizeof(struct ecma119_source_opts));
 	opts.level = level;
 	opts.flags = flags;
-	opts.relaxed_constraints = 0;//constraints;
-	opts.input_charset = NULL;//"UTF-8";
+	opts.relaxed_constraints = 0;
+	opts.input_charset = NULL;
 	opts.ouput_charset = "UTF-8";
 	
 	src = iso_source_new_ecma119(volset, &opts);
diff --git a/test/iso_grow.c b/test/iso_grow.c
index b90f26d..aae5eab 100644
--- a/test/iso_grow.c
+++ b/test/iso_grow.c
@@ -165,8 +165,9 @@ int main(int argc, char **argv)
 	wopts.relaxed_constraints = 0;
 	wopts.input_charset = "UTF-8";
 	wopts.ouput_charset = "UTF-8";
-	wopts.ms_block = ropts.size;
-	wopts.overwrite = malloc(32*2048);
+	/* round up to 32kb aligment = 16 block*/
+	wopts.ms_block = ((ropts.size + 15) / 16 ) * 16;
+	wopts.overwrite = calloc(32, 2048);
 	
 	wsrc = iso_source_new_ecma119(volset, &wopts);
 
@@ -193,7 +194,7 @@ int main(int argc, char **argv)
 		burn_write_opts_set_underrun_proof(burn_options, 1);
 		
 		//mmm, check for 32K alignment?
-	  	burn_write_opts_set_start_byte(burn_options, ropts.size * 2048);
+	  	burn_write_opts_set_start_byte(burn_options, wopts.ms_block * 2048);
 		
 		if (burn_write_opts_auto_write_type(burn_options, target_disc,
 					reasons, 0) == BURN_WRITE_NONE) {
diff --git a/test/iso_read.c b/test/iso_read.c
index 9dbb05b..e7438a5 100644
--- a/test/iso_read.c
+++ b/test/iso_read.c
@@ -64,11 +64,30 @@ print_dir(struct iso_tree_node_dir *dir, int level)
 			print_permissions(iso_tree_node_get_permissions(node));
 			printf(" %s -> %s \n", iso_tree_node_get_name(node),
 			       iso_tree_node_symlink_get_dest((struct iso_tree_node_symlink*)node) );
-		}
+		} else {
+			/* boot catalog */
+			printf("%s-[C] ", sp);
+			print_permissions(iso_tree_node_get_permissions(node));
+			printf(" %s\n", iso_tree_node_get_name(node) );
+		} 
 	}
 	iso_tree_iter_free(iter);
 }
 
+static void
+check_el_torito(struct iso_volume *volume)
+{
+	struct iso_tree_node *cat, *img;
+	
+	if (iso_volume_get_boot_image(volume, &img, &cat)) {
+		
+		printf("\nEL-TORITO INFORMATION\n");
+		printf("=====================\n\n");
+		printf("Catalog: %s\n", iso_tree_node_get_name(cat) );
+		printf("Image: %s\n", iso_tree_node_get_name(img) );
+	}
+}
+
 int main(int argc, char **argv)
 {
 	struct ecma119_read_opts opts;
@@ -131,6 +150,8 @@ int main(int argc, char **argv)
 	
 	print_dir(iso_volume_get_root(volume), 0);
 	
+	check_el_torito(volume);
+	
 	printf("\n\n");
 	
 	data_source_free(src);