2008-03-21  Robert Millan  <address@hidden>

	* disk/i386/pc/biosdisk.c (grub_biosdisk_rw): Fix CHS limit check,
	as per http://www.allensmith.net/Storage/HDDlimit/Int13h.htm

diff -urp grub2/disk/i386/pc/biosdisk.c tmp/disk/i386/pc/biosdisk.c
--- grub2/disk/i386/pc/biosdisk.c	2008-02-03 09:27:15.000000000 +0100
+++ tmp/disk/i386/pc/biosdisk.c	2008-03-21 16:11:20.000000000 +0100
@@ -237,15 +237,17 @@ grub_biosdisk_rw (int cmd, grub_disk_t d
     {
       unsigned coff, hoff, soff;
       unsigned head;
-      unsigned real_sector = (unsigned) sector;
       
-      /* It is impossible to reach over 2TB with the traditional
-	 CHS access.  */
-      if (sector > ~0UL)
+      /* It is impossible to reach over 8064 MiB (a bit less than LBA24) with
+	 the traditional CHS access.  */
+      if (sector >
+	  1024 /* cylinders */ *
+	  256 /* heads */ *
+	  63 /* spt */)
 	return grub_error (GRUB_ERR_OUT_OF_RANGE, "out of disk");
 
-      soff = real_sector % data->sectors + 1;
-      head = real_sector / data->sectors;
+      soff = sector % data->sectors + 1;
+      head = sector / data->sectors;
       hoff = head % data->heads;
       coff = head / data->heads;