Enabled recognition of multi-session emulation with partition offset 16 and GPT

libisoburn/isofs_wrap.c

@@ -87,6 +87,18 @@ uint32_t iso_read_lsb(const uint8_t *buf, int bytes)
 }
 
 
+static
+uint64_t iso_read_lsb64(const uint8_t *buf)
+{
+    int i;
+    uint64_t ret = 0;
+
+    for (i=0; i < 8; i++)
+        ret += ((uint64_t) buf[i]) << (i * 8);
+    return ret;
+}
+
+
 /* API function. See libisoburn.h
 */
 IsoImage *isoburn_get_attached_image(struct burn_drive *d)
@@ -640,6 +652,42 @@ int isoburn_get_img_partition_offset(struct burn_drive *drive,
 }
 
 
+/* Try to read partition start and size block number from given GPT entry */
+int isoburn_get_gpt_entry(struct isoburn *o, int partno,
+                          uint64_t *start_lba, uint64_t *size, int flag)
+{
+ uint32_t part_start, entry_count, entry_size, part_lba, end_lba;
+ uint8_t *gpt, *part;
+
+
+ /* Check for GPT header block */
+ gpt = o->target_iso_head + 512;
+ if(memcmp(gpt, "EFI PART", 8) != 0)
+   return(0);
+ if(gpt[8] != 0x00 || gpt[9] != 0x00 || gpt[10] != 0x01 || gpt[11] != 0x00)
+   return(0);
+ part_start = iso_read_lsb64(gpt + 72);
+ entry_count = iso_read_lsb64(gpt + 80);
+ entry_size = iso_read_lsb64(gpt + 84);
+
+ /* Read partition entry */
+ if(partno < 1)
+   return(0);
+ if(((uint64_t) partno) > entry_count)
+   return(0);
+ if(part_start * 512 + partno * entry_size > 32768)
+   return(0);
+ part = o->target_iso_head + part_start * 512 + (partno - 1) * entry_size; 
+ part_lba = iso_read_lsb64(part + 32);
+ end_lba = iso_read_lsb64(part + 40);
+ if(end_lba < part_lba)
+   return(0);
+ *start_lba = part_lba;
+ *size = end_lba - part_lba + 1;
+ return(1);
+}
+
+
 /* Check for MBR signature and a first partition that starts at a 2k block 
    and ends where the image ends.
    If not too large or too small, accept its start as partition offset.
@@ -649,6 +697,7 @@ static int isoburn_inspect_partition(struct isoburn *o, uint32_t img_size,
 {
  uint8_t *mbr, *part, *buf= NULL;
  uint32_t offst, numsec;
+ uint64_t gpt_start_lba, gpt_size;
  struct ecma119_pri_vol_desc *pvm;
  off_t data_count;
  int ret;
@@ -671,9 +720,20 @@ static int isoburn_inspect_partition(struct isoburn *o, uint32_t img_size,
  if(part[1] == 0 && part[2] == 0 && part[3] == 0)
    {ret= 2; goto ex;} /* Zero C/H/S start address */
 
- /* Does it match the normal ISO image ? */
  offst= iso_read_lsb(part + 8, 4);
  numsec= iso_read_lsb(part + 12, 4);
+
+ /* Is it GPT ? */
+ if(part[4] == 0xee && offst == 1) {
+   ret= isoburn_get_gpt_entry(o, 1, &gpt_start_lba, &gpt_size, 0);
+   if(ret > 0 && gpt_start_lba < ((uint64_t) 1) << 32 &&
+      gpt_size < ((uint64_t) 1) << 32) {
+     offst= gpt_start_lba;
+     numsec= gpt_size;
+   }
+ }
+
+ /* Does it match the normal ISO image ? */
  if(offst < 64)
    {ret= 2; goto ex;} /* Zero or unusably small partition start */
  if((offst % 4) || (numsec % 4))

xorriso/xorriso_timestamp.h

@@ -1 +1 @@
-#define Xorriso_timestamP "2023.06.07.200919"
+#define Xorriso_timestamP "2023.07.12.182812"