diff -ur xorriso-1.2.1/libisofs/eltorito.c xorriso-1.2.1-mod/libisofs/eltorito.c
--- xorriso-1.2.1/libisofs/eltorito.c	2012-01-27 17:02:41.000000000 +0100
+++ xorriso-1.2.1-mod/libisofs/eltorito.c	2012-01-30 02:34:48.266770529 +0100
@@ -1113,6 +1113,16 @@
     ret = make_boot_info_table(buf, t->ms_block + (uint32_t) 16,
                                t->bootsrc[idx]->sections[0].block,
                                (uint32_t) imgsize);
+    if (1) {
+      uint64_t blk;
+      if (imgsize < 1024)
+        return iso_msg_submit(t->image->id, ISO_ISOLINUX_CANT_PATCH, 0,
+            "Isolinux image too small. We won't patch it.");
+
+      blk = ((uint64_t) t->bootsrc[idx]->sections[0].block) * 4 + 2;
+      iso_lsb((buf + 1024 - 12), blk & 0xffffffff, 4);
+      iso_lsb((buf + 1024 - 8), blk >> 32, 4);
+    }
     return ret;
 }
 
diff -ur xorriso-1.2.1/libisofs/system_area.c xorriso-1.2.1-mod/libisofs/system_area.c
--- xorriso-1.2.1/libisofs/system_area.c	2012-01-27 17:02:41.000000000 +0100
+++ xorriso-1.2.1-mod/libisofs/system_area.c	2012-01-30 02:30:27.017381391 +0100
@@ -182,7 +182,7 @@
 */
 static
 int make_grub_msdos_label(uint32_t img_blocks, int sph, int hpc,
-                          uint8_t *buf, int flag)
+                          uint8_t *buf, int flag, uint64_t blk)
 {
     uint8_t *wpt;
     uint32_t end_lba, end_sec, end_head, end_cyl;
@@ -191,6 +191,11 @@
     iso_compute_cyl_head_sec(&img_blocks, hpc, sph,
                              &end_lba, &end_sec, &end_head, &end_cyl, 0);
 
+    blk = blk * 4 + 1;
+
+    wpt = buf + 0x5c;
+    for (i = 0; i < 8; i++)
+      wpt[i] = blk >> (i * 8);
     /* 1) Zero-fill 446-510 */
     wpt = buf + 446;
     memset(wpt, 0, 64);
@@ -739,7 +744,8 @@
     if (sa_type == 0 && (t->system_area_options & 1)) {
         /* Write GRUB protective msdos label, i.e. a simple partition table */
         ret = make_grub_msdos_label(img_blocks, t->partition_secs_per_head,
-                                    t->partition_heads_per_cyl, buf, 0);
+                                    t->partition_heads_per_cyl, buf, 0,
+				    t->bootsrc[0]->sections[0].block);
         if (ret != ISO_SUCCESS) /* error should never happen */
             return ISO_ASSERT_FAILURE;
     } else if(sa_type == 0 && (t->system_area_options & 2)) {
@@ -766,7 +772,8 @@
     } else if ((t->partition_offset > 0 || will_append) && sa_type == 0) {
         /* Write a simple partition table. */
         ret = make_grub_msdos_label(img_blocks, t->partition_secs_per_head,
-                                    t->partition_heads_per_cyl, buf, 2);
+                                    t->partition_heads_per_cyl, buf, 2,
+				    t->bootsrc[0]->sections[0].block);
         if (ret != ISO_SUCCESS) /* error should never happen */
             return ISO_ASSERT_FAILURE;
         if (t->partition_offset == 0) {
diff -ur xorriso-1.2.1/xorriso/emulators.c xorriso-1.2.1-mod/xorriso/emulators.c
--- xorriso-1.2.1/xorriso/emulators.c	2012-01-27 17:02:41.000000000 +0100
+++ xorriso-1.2.1-mod/xorriso/emulators.c	2012-01-30 01:56:29.851351371 +0100
@@ -1895,6 +1895,14 @@
        goto problem_handler_boot;
      if(strcmp(argpt, "-isohybrid-mbr")==0)
        xorriso->system_area_options= (xorriso->system_area_options & ~3) | 2;
+   } else if(strcmp(argpt, "--grub-boot")==0) {
+     if(i+1>=argc)
+       goto not_enough_args;
+     i++; 
+     ret= Xorriso_set_system_area_path(xorriso, argv[i], 0);
+     if(ret <= 0)
+       goto problem_handler_boot;
+     xorriso->patch_isolinux_image= 1 | 4;
    } else if(strcmp(argpt, "--protective-msdos-label")==0) {
      xorriso->system_area_options= (xorriso->system_area_options & ~3) | 1;
    } else if(strcmp(argpt, "--boot-catalog-hide")==0) {