From 72bae78465e448f840d6b58209dee6ca9a10e71f Mon Sep 17 00:00:00 2001
From: okuji <okuji@localhost>
Date: Sat, 3 Jun 2000 06:08:05 +0000
Subject: [PATCH] fix a bug about a LBA check in stage2.

---
 ChangeLog     |  8 ++++++++
 stage2/asm.S  |  5 +++++
 stage2/bios.c | 25 ++++++++++---------------
 3 files changed, 23 insertions(+), 15 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index a2a54f694..a0a084ff2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2000-06-03  OKUJI Yoshinori  <okuji@gnu.org>
+
+	* stage2/asm.S (check_int13_extensions): Check the bitmap only
+	if FORCE_LBA is zero.
+	* stage2/bios.c (get_diskinfo): Get rid of the wrong check for
+	the bit 0 of DRP.FLAGS. Now the bitmap check is correctly
+	performed in the function check_int13_extensions.
+	
 2000-06-02  OKUJI Yoshinori  <okuji@gnu.org>
 
 	* docs/user-ref.texi (Invoking the grub shell): Added a caution.
diff --git a/stage2/asm.S b/stage2/asm.S
index fde156740..e7f139e6d 100644
--- a/stage2/asm.S
+++ b/stage2/asm.S
@@ -1023,6 +1023,11 @@ ENTRY(check_int13_extensions)
 	jc	1f
 	cmpw	$0xaa55, %bx
 	jne	1f
+
+	/* check if AH=0x42 is supported if FORCE_LBA is zero */
+	movb	EXT_C(force_lba), %al
+	testb	%al, %al
+	jnz	1f
 	andw	$1, %cx
 	jz	1f
 
diff --git a/stage2/bios.c b/stage2/bios.c
index dca467a82..425de916d 100644
--- a/stage2/bios.c
+++ b/stage2/bios.c
@@ -158,22 +158,17 @@ get_diskinfo (int drive, struct geometry *geometry)
 	  err = get_diskinfo_int13_extensions (drive, &drp);
 	  if (! err)
 	    {
-	      /* How many buggy BIOSes are there in the world...
-		 Some BIOSes don't set the flag correctly, even if LBA
-		 read/write is supported, so we cannot help assuming
-		 that the functions are supported by default and
-		 clearing the flag when either of them fails. *sigh*  */
+	      /* Set the LBA flag.  */
+	      geometry->flags = BIOSDISK_FLAG_LBA_EXTENSION;
 
-	      /* Make sure that LBA read/write functions are supported.  */
-	      if (force_lba || (drp.flags & 1))
-		{
-		  geometry->flags = BIOSDISK_FLAG_LBA_EXTENSION;
-		  
-		  /* FIXME: when the 2TB limit becomes critical, we must
-		     change the type of TOTAL_SECTORS to unsigned long
-		     long.  */
-		  total_sectors = drp.total_sectors & ~0L;
-		}
+	      /* I'm not sure if GRUB should check the bit 1 of DRP.FLAGS,
+		 so I omit the check for now. - okuji  */
+	      /* if (drp.flags & (1 << 1)) */
+	       
+	      /* FIXME: when the 2TB limit becomes critical, we must
+		 change the type of TOTAL_SECTORS to unsigned long
+		 long.  */
+	      total_sectors = drp.total_sectors & ~0L;
 	    }
 	}