From 1f486fd78b17fa2ad0bf37ed772dc5b8fe2d3b21 Mon Sep 17 00:00:00 2001
From: Thomas Schmitt <scdbackup@gmx.net>
Date: Tue, 19 Oct 2010 10:14:26 +0200
Subject: [PATCH] Coordinated appending of partition images with situations
 other than isohybrid MBR production or partition offset.

---
 libisofs/ecma119.c     |  5 +++++
 libisofs/libisofs.h    |  6 +++++-
 libisofs/messages.c    |  2 ++
 libisofs/system_area.c | 27 +++++++++++++++++++++------
 4 files changed, 33 insertions(+), 7 deletions(-)

diff --git a/libisofs/ecma119.c b/libisofs/ecma119.c
index 4a5a05d..26d88ce 100644
--- a/libisofs/ecma119.c
+++ b/libisofs/ecma119.c
@@ -1615,6 +1615,11 @@ int ecma119_image_new(IsoImage *src, IsoWriteOpts *opts, Ecma119Image **img)
     } else {
         system_area_options = opts->system_area_options & 0xfc;
     }
+    if ((system_area_options & 0xfc) != 0)
+        for (i = 0; i < 4; i++)
+            if (opts->appended_partitions[i] != NULL)
+                return ISO_NON_MBR_SYS_AREA;
+
     target->system_area_data = NULL;
     if (system_area != NULL) {
         target->system_area_data = calloc(32768, 1);
diff --git a/libisofs/libisofs.h b/libisofs/libisofs.h
index 81a2c5a..d38be5b 100644
--- a/libisofs/libisofs.h
+++ b/libisofs/libisofs.h
@@ -6357,7 +6357,11 @@ int iso_md5_match(char first_md5[16], char second_md5[16]);
 #define ISO_BAD_PARTITION_NO       0xE830FE8F
 
 /** Cannot open data file for appended partition (FAILURE, HIGH, -370) */
-#define ISO_BAD_PARTITION_FILE      0xE830FE8E
+#define ISO_BAD_PARTITION_FILE     0xE830FE8E
+
+/** May not combine appended partition with non-MBR system area
+                                                       (FAILURE, HIGH, -371) */
+#define ISO_NON_MBR_SYS_AREA       0xE830FE8D
 
 
 /* Internal developer note: 
diff --git a/libisofs/messages.c b/libisofs/messages.c
index 92feb5e..79a77fd 100644
--- a/libisofs/messages.c
+++ b/libisofs/messages.c
@@ -357,6 +357,8 @@ const char *iso_error_to_msg(int errcode)
         return "Partition number out of range";
     case ISO_BAD_PARTITION_FILE:
         return "Cannot open data file for appended partition";
+    case ISO_NON_MBR_SYS_AREA:
+        return "May not combine appended partition with non-MBR system area";
     default:
         return "Unknown error";
     }
diff --git a/libisofs/system_area.c b/libisofs/system_area.c
index 691e2d4..de7f902 100644
--- a/libisofs/system_area.c
+++ b/libisofs/system_area.c
@@ -436,8 +436,9 @@ static int make_mips_volume_header(Ecma119Image *t, uint8_t *buf, int flag)
    doc/boot_sectors.txt section "MIPS Little Endian" which was derived
    by Thomas Schmitt from
    cdrkit-1.1.10/genisoimage/boot-mipsel.c by Steve McIntyre which is based
-   on work of Florian Lohoff and Thiemo Seufer, and from <elf.h> by Free
-   Software Foundation, Inc.
+   on work of Florian Lohoff and Thiemo Seufer,
+   and from <elf.h> by Free Software Foundation, Inc.
+
    Both functions are entirely under copyright (C) 2010 Thomas Schmitt.
 */
 
@@ -566,7 +567,7 @@ static int make_mipsel_boot_block(Ecma119Image *t, uint8_t *buf, int flag)
 
 int iso_write_system_area(Ecma119Image *t, uint8_t *buf)
 {
-    int ret, int_img_blocks, sa_type, i;
+    int ret, int_img_blocks, sa_type, i, will_append = 0;
     uint32_t img_blocks;
 
     if ((t == NULL) || (buf == NULL)) {
@@ -577,6 +578,12 @@ int iso_write_system_area(Ecma119Image *t, uint8_t *buf)
     memset(buf, 0, 16 * BLOCK_SIZE);
 
     sa_type = (t->system_area_options >> 2) & 0x3f;
+    for (i = 0; i < 4; i++)
+        if (t->appended_partitions[i] != NULL) {
+            will_append = 1;
+    break;
+        }
+
     img_blocks = t->curblock;
     if (t->system_area_data != NULL) {
         /* Write more or less opaque boot image */
@@ -619,20 +626,28 @@ int iso_write_system_area(Ecma119Image *t, uint8_t *buf)
                                t->partition_secs_per_head, 0, 1, 0x17, buf, 1);
         if (ret != 1)
             return ret;
-    } else if(sa_type == 1) {
+    } else if (sa_type == 1) {
         ret = make_mips_volume_header(t, buf, 0);
         if (ret != ISO_SUCCESS)
             return ret;
-    } else if(sa_type == 2) {
+    } else if (sa_type == 2) {
         ret = make_mipsel_boot_block(t, buf, 0);
         if (ret != ISO_SUCCESS)
             return ret;
-    } else if(t->partition_offset > 0 && sa_type == 0) {
+    } 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);
         if (ret != ISO_SUCCESS) /* error should never happen */
             return ISO_ASSERT_FAILURE;
+        if (t->partition_offset == 0) {
+            /* Re-write partion entry 1 : start at 0, type Linux */
+            ret = write_mbr_partition_entry(1, 0x83, 0, img_blocks,
+                        t->partition_secs_per_head, t->partition_heads_per_cyl,
+                        buf, 0);
+            if (ret < 0)
+                return ret;
+        }
     }
 
     if (t->partition_offset > 0 && sa_type == 0) {