1 files changed, 93 insertions, 0 deletions
diff --git a/src/pmbr.c b/src/pmbr.c
index a9bbfb8..a958f83 100644
--- a/src/pmbr.c
+++ b/src/pmbr.c
@@ -62,3 +62,96 @@ mbr_new (uint64_t lbas)
 
   return ret;
 }
+
+
+static CHS
+sector_to_chs (uint32_t lba)
+{
+  CHS ret;
+  int c;
+  int h;
+  int s;
+
+  c = lba / (63 * 255);
+
+  if (c > 1023)
+    {
+      ret.head = 254;
+      ret.cs = MBR_CS (1023, 63);
+      return ret;
+    }
+
+  lba -= (c * 63 * 255);
+  h = lba / 63;
+  lba -= (h * 63);
+  s = lba + 1;
+
+
+  ret.head = h;
+  ret.cs = MBR_CS (c, s);
+
+  return ret;
+}
+
+void
+mbr_set_entry0_from_gpt_header (MBR_entry * m, GPT_header * h)
+{
+  MBR ret = { 0 };
+  uint32_t start = 1;
+  uint32_t end = h->first_usable_lba - 1;
+
+
+  m->bootable = 0;
+  m->chs_start = sector_to_chs (start);
+  m->system = MBR_PARTITION_TYPE_EFI;
+  m->chs_end = sector_to_chs (end);
+  m->start = start;
+  m->size = (end - start) + 1;
+
+}
+
+void
+mbr_entry_from_gpt_entry (MBR_entry * m, GPT_entry * g, int bootable,
+                          uint8_t type)
+{
+  MBR ret = { 0 };
+  uint32_t start = g->start;
+  uint32_t end = g->end;
+
+
+  m->system = type;
+  m->bootable = bootable ? MBR_PARTITION_BOOTABLE : 0x00;
+  m->chs_start = sector_to_chs (start);
+  m->chs_end = sector_to_chs (end);
+  m->start = start;
+  m->size = (end - start) + 1;
+}
+
+void
+mbr_wedge_entry (MBR_entry * m)
+{
+  MBR ret = { 0 };
+
+  int c = MBR_CYLINDER (m->chs_end.cs);
+  int s = MBR_SECTOR (m->chs_end.cs);
+  int h = m->chs_end.head;
+
+  while ((s != 63) || (h != 254))
+    {
+      s++;
+      if (s == 64)
+        {
+          s = 1;
+          h++;
+          if (h == 255)
+            {
+              c++;
+              h = 0;
+            }
+        }
+      m->size++;
+    }
+
+  m->chs_end.head = h;
+  m->chs_end.cs = MBR_CS (c, s);
+}