New API call iso_write_opts_set_system_area() acts like mkisofs option -G

libisofs/ecma119.c

@@ -73,6 +73,9 @@ void ecma119_image_free(Ecma119Image *t)
     if (t->output_charset != NULL)
         free(t->output_charset);
 
+    if (t->system_area_data != NULL)
+        free(t->system_area_data);
+
 #ifdef Libisofs_with_checksumS
     if (t->checksum_ctx != NULL) { /* dispose checksum context */
         char md5[16];
@@ -1127,6 +1130,17 @@ int ecma119_image_new(IsoImage *src, IsoWriteOpts *opts, Ecma119Image **img)
     target->eltorito = (src->bootcat == NULL ? 0 : 1);
     target->catalog = src->bootcat;
 
+    target->system_area_data = NULL;
+    if(opts->system_area_data != NULL) {
+        target->system_area_data = calloc(32768, 1);
+        if (target->system_area_data == NULL) {
+            ret = ISO_OUT_OF_MEM;
+            goto target_cleanup;
+        }
+        memcpy(target->system_area_data, opts->system_area_data, 32768);
+    }
+    target->system_area_options = opts->system_area_options;
+
     target->input_charset = strdup(iso_get_local_charset(0));
     if (target->input_charset == NULL) {
         ret = ISO_OUT_OF_MEM;
@@ -1700,6 +1714,8 @@ void iso_write_opts_free(IsoWriteOpts *opts)
     }
 
     free(opts->output_charset);
+    if(opts->system_area_data != NULL)
+        free(opts->system_area_data);
     free(opts);
 }
 
@@ -2085,3 +2101,28 @@ int iso_write_opts_get_data_start(IsoWriteOpts *opts, uint32_t *data_start,
     return ISO_SUCCESS;
 }
 
+/*
+ * @param data     Either NULL or 32 kB of data. Do not submit less bytes !
+ * @param options  bit0 = apply GRUB protective msdos label
+ * @param flag     bit0 = invalidate any attached system area data
+ *                        same as data == NULL
+ */
+int iso_write_opts_set_system_area(IsoWriteOpts *opts, char data[32768],
+                                   int options, int flag)
+{
+    if (data == NULL || (flag & 1)) { /* Disable */
+        if (opts->system_area_data != NULL)
+            free(opts->system_area_data);
+        opts->system_area_data = NULL;
+    } else {
+        if (opts->system_area_data == NULL) {
+            opts->system_area_data = calloc(32768, 1);
+            if (opts->system_area_data == NULL)
+                return ISO_OUT_OF_MEM;
+        }
+        memcpy(opts->system_area_data, data, 32768);
+    }
+    opts->system_area_options = options & 1;
+    return ISO_SUCCESS;
+}
+

libisofs/ecma119.h

@@ -298,6 +298,11 @@ struct iso_write_opts {
      */
     char *scdbackup_tag_written;
 
+    /*
+     * See ecma119_image : System Area related information
+     */
+    char *system_area_data;
+    int system_area_options;
 };
 
 typedef struct ecma119_image Ecma119Image;
@@ -436,6 +441,22 @@ struct ecma119_image
     IsoFileSrc *cat; /**< location of the boot catalog in the new image */
     IsoFileSrc *bootimg; /**< location of the boot image in the new image */
 
+    /*
+     * System Area related information
+     */
+    /* Content of an embedded boot image. Valid if not NULL.
+     * In that case it must point to a memory buffer at least 32 kB.
+     */
+    char *system_area_data;
+    /*
+     * bit0= make bytes 446 - 512 of the system area a partition
+     *       table which reserves partition 1 from byte 63*512 to the
+     *       end of the ISO image. Assumed are 63 secs/hed, 255 head/cyl.
+     *       (GRUB protective msdos label.)
+     *       This works with and without system_area_data.
+     */
+    int system_area_options;
+
     /*
      * Number of pad blocks that we need to write. Padding blocks are blocks
      * filled by 0s that we put between the directory structures and the file

libisofs/eltorito.c

@@ -333,9 +333,11 @@ int create_image(IsoImage *image, const char *image_path,
     boot->image = (IsoFile*)imgfile;
     iso_node_ref(imgfile); /* get our ref */
     boot->bootable = 1;
+    boot->isolinux_options = 0;
     boot->type = boot_media_type;
-    boot->load_size = load_sectors;
     boot->partition_type = partition_type;
+    boot->load_seg = 0;
+    boot->load_size = load_sectors;
 
     if (bootimg) {
         *bootimg = boot;

libisofs/eltorito.h

@@ -39,7 +39,8 @@ struct el_torito_boot_image {
     /**
      * isolinux options
      * bit 0 -> whether to patch image
-     * bit 1 -> whether to create isolinux image
+     * bit 1 -> whether to put built-in isolinux 3.72 isohybrid-MBR into image
+     *          System Area (deprecated)
      */
     unsigned int isolinux_options:2;
     unsigned char type; /**< The type of image */

libisofs/libisofs.h

@@ -1680,6 +1680,32 @@ int iso_write_opts_set_overwrite_buf(IsoWriteOpts *opts, uint8_t *overwrite);
  */
 int iso_write_opts_set_fifo_size(IsoWriteOpts *opts, size_t fifo_size);
 
+/*
+ * Attach 32 kB of binary data which shall get written to the first 32 kB 
+ * of the ISO image, the ECMA-119 System Area. This space is intended for
+ * system dependent boot software, e.g. a Master Boot Record which allows to
+ * boot from USB sticks or hard disks. ECMA-119 makes no own assumptions or
+ * prescriptions about the byte content.
+ *
+ * If system area data are given or options bit0 is set, then bit1 of
+ * el_torito_set_isolinux_options() is automatically disabled.
+ * @param data
+ *        Either NULL or 32 kB of data. Do not submit less bytes !
+ * @param options
+ *        Can cause manipulations of submitted data before they get written:
+ *        bit0= apply a --protective-msdos-label as of grub-mkisofs.
+ *              This means to patch bytes 446 to 512 of the system area so
+ *              that one partition is defined which begins at the second
+ *              512-byte block of the image and ends where the image ends.
+ * @param flag
+ *        bit0 = invalidate any attached system area data. Same as data == NULL
+ * @return
+ *        ISO_SUCCESS or error
+ * @since 0.6.30
+ */
+int iso_write_opts_set_system_area(IsoWriteOpts *opts, char data[32768],
+                                   int options, int flag);
+
 /**
  * Inquire the start address of the file data blocks after having used
  * IsoWriteOpts with iso_image_create_burn_source().
@@ -2325,19 +2351,27 @@ void el_torito_set_no_bootable(ElToritoBootImage *bootimg);
 void el_torito_patch_isolinux_image(ElToritoBootImage *bootimg);
 
 /**
- * Specifies options for IsoLinux boot images. This should only be used with
+ * Specifies options for ISOLINUX or GRUB boot images. This should only be used
- * isolinux boot images.
+ * if the type of boot image is known.
  *
  * @param options
  *        bitmask style flag. The following values are defined:
  *
- *        bit 0 -> 1 to patch the image, 0 to not
+ *        bit 0 -> 1 to patch the boot info table of the boot image.
- *                 Patching the image involves the writing of a 56 bytes
+ *                 1 does the same as mkisofs option -boot-info-table.
- *                 boot information table at offset 8 of the boot image file.
+ *                 Needed for ISOLINUX and for GRUB rescue boot images.
- *                 The original boot image file will not be modified. This is
+ *                 The table is located at byte 8 of the boot image file.
- *                 needed to allow isolinux images to be bootable.
+ *                 Its size is 56 bytes. 
- *        bit 1 -> 1 to generate an hybrid image with MBR, 0 to not
+ *                 The original boot image file on disk will not be modified.
- *                 An hybrid image is a boot image that boots from either
+ *
+ *        bit 1 -> 1 to generate a ISOLINUX isohybrid image with MBR.
+ *                 ----------------------------------------------------------
+ *                 @deprecated since 31 Mar 2010:
+ *                 The author of syslinux, H. Peter Anvin requested that this
+ *                 feature shall not be used any more. He intends to cease
+ *                 support for the MBR template that is included in libisofs.
+ *                 ----------------------------------------------------------
+ *                 A hybrid image is a boot image that boots from either
  *                 CD/DVD media or from disk-like media, e.g. USB stick.
  *                 For that you need isolinux.bin from SYSLINUX 3.72 or later.
  *                 IMPORTANT: The application has to take care that the image

libisofs/system_area.c

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2008 Vreixo Formoso
+ * Copyright (c) 2010 Thomas Schmitt
  *
  * This file is part of the libisofs project; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License version 2 
@@ -12,28 +13,104 @@
 #include "filesrc.h"
 
 #include <string.h>
-
+#include <stdio.h>
 
 
 /*
  * Create a MBR for an isohybrid enabled ISOLINUX boot image.
- *
+ * See libisofs/make_isohybrid_mbr.c
- * It is assumed that the caller has verified the readiness of the boot image
+ * Deprecated.
- * by checking for 0xfb 0xc0 0x78 0x70 at bytes 0x40 to 0x43 of isolinux.bin.
- *
- * @param bin_lba    The predicted LBA of isolinux.bin within the emerging ISO.
- * @param img_blocks The predicted number of 2048 byte blocks in the ISO.
- *                   It will get rounded up to full MBs and that many blocks
- *                   must really be written as ISO 9660 image.
- * @param mbr        A buffer of at least 512 bytes to take the result which is
- *                   to be written as the very beginning of the ISO.
- * @param flag    unused yet, submit 0
- * @return  <0 = fatal, 0 = failed , 1 = ok , 2 = ok with size warning
  */
 int make_isohybrid_mbr(int bin_lba, int *img_blocks, char *mbr, int flag);
 
+
+
+/* This is the gesture of grub-mkisofs --protective-msdos-label as explained by
+   Vladimir Serbinenko <phcoder@gmail.com>, 2 April 2010, on grub-devel@gnu.org
+   "Currently we use first and not last entry. You need to:
+    1) Zero-fill 446-510
+    2) Put 0x55, 0xAA into 510-512
+    3) Put 0x80 (for bootable partition), 0, 2, 0 (C/H/S of the start), 0xcd
+      (partition type), [3 bytes of C/H/S end], 0x01, 0x00, 0x00, 0x00 (LBA
+      start in little endian), [LBA end in little endian] at 446-462
+   "
+
+   "C/H/S end" means the CHS address of the last block in the partition.
+   It seems that not "[LBA end in little endian]" but "number of blocks"
+   should go into bytes 458-461. But with a start lba of 1, this is the
+   same number.
+   See also http://en.wikipedia.org/wiki/Master_boot_record
+*/
+int make_grub_msdos_label(int img_blocks, uint8_t *buf, int flag)
+{
+    uint8_t *wpt;
+    unsigned long end_lba, secs, end_sec, end_head, end_cyl;
+    int sph = 63, hpc = 255, i;
+
+    /* Partition table unit is 512 bytes per sector, ECMA-119 unit is 2048 */
+    if (img_blocks >= 0x40000000)
+      img_blocks = 0x40000000 - 1;         /* truncate rather than roll over */
+    secs = end_lba = img_blocks * 4 - 1;   /* last valid 512-lba */
+    end_cyl = secs / (sph * hpc);
+    secs -= end_cyl * sph * hpc;
+    end_head = secs / sph;
+    end_sec = secs - end_head * sph + 1;   /* Sector count starts by 1 */
+    if (end_cyl >= 1024) {
+        end_cyl = 1023;
+        end_head = hpc - 1;
+        end_sec = sph;
+    }
+
+    /* 1) Zero-fill 446-510 */
+    wpt = buf + 446;
+    memset(wpt, 0, 64);
+
+    /* 2) Put 0x55, 0xAA into 510-512 (actually 510-511) */
+    buf[510] = 0x55;
+    buf[511] = 0xAA;
+
+    /* 3) Put 0x80 (for bootable partition), */
+    *(wpt++) = 0x80;
+
+    /* 0, 2, 0 (C/H/S of the start), */
+    *(wpt++) = 0;
+    *(wpt++) = 2;
+    *(wpt++) = 0;
+
+    /* 0xcd (partition type) */
+    *(wpt++) = 0xcd;
+
+    /* [3 bytes of C/H/S end], */
+    *(wpt++) = end_head;
+    *(wpt++) = end_sec | ((end_cyl & 0x300) >> 2);
+    *(wpt++) = end_cyl & 0xff;
+    
+
+    /* 0x01, 0x00, 0x00, 0x00 (LBA start in little endian), */
+    *(wpt++) = 0x01;
+    *(wpt++) = 0x00;
+    *(wpt++) = 0x00;
+    *(wpt++) = 0x00;
+
+    /* [LBA end in little endian] */
+    for (i = 0; i < 4; i++)
+       *(wpt++) = (end_lba >> (8 * i)) & 0xff;
+
+    /* at 446-462 */
+    if (wpt - buf != 462) {
+        fprintf(stderr,
+        "libisofs: program error in make_grub_msdos_label: \"assert 462\"\n");
+        return ISO_ASSERT_FAILURE;
+    }
+    return ISO_SUCCESS;
+}
+
+
 int iso_write_system_area(Ecma119Image *t, uint8_t *buf)
 {
+    int ret;
+    int img_blocks;
+
     if ((t == NULL) || (buf == NULL)) {
         return ISO_NULL_POINTER;
     }
@@ -41,26 +118,29 @@ int iso_write_system_area(Ecma119Image *t, uint8_t *buf)
     /* set buf to 0s */
     memset(buf, 0, 16 * BLOCK_SIZE);
 
-    if (t->catalog != NULL && t->catalog->image->isolinux_options & 0x02) {
+    img_blocks = t->curblock;
-        /* We need to write a MBR for an hybrid image */
+    if (t->system_area_data != NULL) {
-        int ret;
+        /* Write more or less opaque boot image */
-        int img_blocks;
+        memcpy(buf, t->system_area_data, 16 * BLOCK_SIZE);
-
-        img_blocks = t->curblock;
-        ret = make_isohybrid_mbr(t->bootimg->sections[0].block, &img_blocks, (char*)buf, 0);
-
-/* 
-        API description of el_torito_set_isolinux_options() prescribes
-        to pad to full MB.
-        So this is not urgent any more :
-
-        // FIXME the new img_blocks size should be taken into account
-*/
 
+    } else if (t->catalog != NULL &&
+               (t->catalog->image->isolinux_options & 0x0a) == 0x02) {
+        /* Check for isolinux image with magic number of 3.72 and produce
+           an MBR from our built-in template. (Deprecated since 31 Mar 2010)
+        */
+        ret = make_isohybrid_mbr(t->bootimg->sections[0].block,
+                                 &img_blocks, (char*)buf, 0);
         if (ret != 1) {
             /* error, it should never happen */
             return ISO_ASSERT_FAILURE;
         }
+        return ISO_SUCCESS;
+    }
+    if (t->system_area_options & 1) {
+        /* Write GRUB protective msdos label, i.e. a isimple partition table */
+        ret = make_grub_msdos_label(img_blocks, buf, 0);
+        if (ret != 1) /* error should never happen */
+            return ISO_ASSERT_FAILURE;
     }
     return ISO_SUCCESS;
 }