Add LBA support

ChangeLog

@@ -1,3 +1,26 @@
+1999-03-03  Gordon Matzigkeit  <gord@trick.fig.org>
+
+	* shared_src/asm.S (biosdisk): Use LBA mode if high nibble of
+	GEOMETRY is nonzero.
+	(get_diskinfo): Set high nibble of GEOMETRY (0xf0000000) to 1 if
+	LBA mode is detected.
+
+1999-03-02  Gordon Matzigkeit  <gord@trick.fig.org>
+
+	* shared_src/disk_io.c (make_saved_active): Use BIOSDISK_READ and
+	BIOSDISK_WRITE.
+
+	* shared_src/cmdline.c (enter_cmdline): Use BIOSDISK_WRITE.
+
+	* shared_src/shared.h (BIOSDISK_SUBFUNC_READ,
+	BIOSDISK_SUBFUNC_WRITE): Delete constants.
+
+	* shared_src/asm.S (biosdisk): Change subfunc argument to be
+	read=0, write=1.
+
+	* configure.in: Drop redundant AC_PROG_INSTALL.  From OKUJI
+	Yoshinori.
+
 1999-03-01  Gordon Matzigkeit  <gord@trick.fig.org>
 
 	* debian/rules (binary-arch): Properly install README.debian.

NEWS

@@ -3,6 +3,7 @@ NEWS - list of user-visible changes between releases of GRUB
 New in 0.5.90 - 1999-03-01, Gordon Matzigkeit:
 * Bug fixes.
 * GRUB understands symlinks on ext2fs (but still not ffs).
+* The GRUB stage2 uses LBA mode and AWARD extensions if they are supported.
 * Many source code and build cleanups to comply with GNU standards.
 
 New in 0.5 - 1998-08-20, Erich Boleyn:

configure.in

@@ -43,7 +43,6 @@ AC_SUBST(stage2debug)
 # Programs
 #
 
-AC_PROG_INSTALL
 AC_CHECK_TOOL(CC, gcc)
 AC_CHECK_TOOL(LD, ld)
 AC_CHECK_TOOL(OBJCOPY, objcopy)

debian/changelog

@@ -1,3 +1,9 @@
+grub (0.5.91) unstable; urgency=low
+
+  * Added support for LBA mode and BIOS extensions.
+
+ --
+
 grub (0.5.90) unstable; urgency=low
 
   * Beta-testing release.

shared_src/asm.S

@@ -330,15 +330,13 @@ realcseg:
 
 
 /*
- * biosdisk(subfunc, drive, geometry, sector, nsec, segment)
+ * biosdisk(write, drive, geometry, sector, nsec, segment)
  *	Read/write "nsec" sectors from disk to real segment "segment"
  *		offset zero
  *
- *   If it will fit into the BIOS geometry, it tries the INT 0x13
+ *   Will try INT 0x13 LBA (AH=0x42/0x43) or standard (AH=0x2/0x3)
- *   AH=<subfunction> interface, else if it is a hard disk, it will
+ *   depending on probed geometry.  For addresses out of the translated
- *   try the hard disk LBA calls (not yet implemented).  If these
+ *   area, it returns BIOS_GEOMETRY_ERROR.
- *   won't work, or otherwise it is out of the translated area, then
- *   it returns BIOS_GEOMETRY_ERROR.
  */
 
 ENTRY(biosdisk)
@@ -350,10 +348,56 @@ ENTRY(biosdisk)
 	push	%edx
 	push	%esi
 
+	/* Check whether we have LBA. */
+	movb	0x13(%ebp), %al
+	shrb	$4, %al
+	jz	disk_compute_args	/* nope. */
+
+	/* set up disk address packet for extended calls (LBA mode) */
+	movl	0x14(%ebp), %eax	/* absolute block number */
+	movl	%eax, dap_block
+	xorl	%eax, %eax
+	movl	%eax, dap_block + 4
+
+	movb	0x18(%ebp), %al		/* number of sectors */
+	movw	%ax, dap_blocks
+
+	/* set up the buffer address */
+	xorl	%eax, %eax
+	movw	0x1c(%ebp), %ax		/* segment */
+	shll	$4, %eax
+	movl	%eax, dap_buffer
+	movl	$disk_address_packet, %esi
+
+	xorb	%bl, %bl
+	movb	0x8(%ebp), %bh		/* read=0, write=1 */
+	addb	$0x42, %bh		/* convert to extended subfunction */
+
+	movb	0xc(%ebp), %dl		/* drive */
+
+	call	EXT_C(prot_to_real)	/* enter real mode */
+	.code16
+
+	movw	%bx, %ax
+	int	$0x13			/* do the operation */
+
+	/* set success return value */
+	movb	$0, %bl
+
+	/* did we actually succeed? */
+	data32
+	jnc	disk_exit_16
+
+	data32
+	call	EXT_C(real_to_prot)	/* back to protected mode */
+	.code32
+
+	/* either failed, or a floppy, so try standard BIOS calls */
+disk_compute_args:
 	/*
-	 * "geometry" is a longword representing the BIOS geometry:
+	 * GEOMETRY is a longword representing the BIOS geometry:
-	 *       6 bit zero
+	 *       4 bit BIOS extension (0 = none, 1 = LBA)
-	 *	10 bit cylinder   (bytes 2 & 3)
+	 *	12 bit cylinder   (bytes 2 & 3)
 	 *	 8 bit head       (byte 1)
 	 *	 8 bit sector     (byte 0)
 	 */
@@ -379,15 +423,27 @@ ENTRY(biosdisk)
 	/* check cylinder offset, is there a geometry problem here? */
 	movl	0x10(%ebp), %ebx
 	shrl	$16, %ebx
+	andb	$0xf, %bh	/* mask out bios extension code */
 	cmpl	%ebx, %eax
 
 	/* if not, go on to standard read function */
 	jle	disk_use_standard_bios
 
-	/* XXX else we better use LBA or generate a geometry error */
 	movl	$BIOSDISK_ERROR_GEOMETRY, %eax
 	jmp	disk_exit_32
 
+disk_address_packet:
+	.align	4
+	.byte	0x20			/* length of packet */
+	.byte	0			/* reserved */
+dap_blocks:
+	.word	0			/* number of blocks */
+dap_buffer:
+	.long	0			/* buffer address */
+dap_block:
+	.long	0			/* absolute block number */
+	.long	0
+
 	/*
 	 *  This portion implements the BIOS standardized
 	 *  INT 0x13/AH=<subfunc> interface.
@@ -396,9 +452,10 @@ disk_use_standard_bios:
 
 	shll	$8, %edx		/* get head number to %dh */
 	xchgl	%eax, %ecx		/* cylinder to %cx, sector to %al */
-	/* cylinder; the highest 2 bits of cyl is in %cl */
+	/* FIXME: cylinder; bits 10,11 of cyl are in %dh */
+	/* cylinder; bits 8,9 of cyl are in %cl */
 	xchgb	%ch, %cl
-	rorb	$2, %cl
+	shlb	$6, %cl
 	incb	%al			/* sector; sec starts from 1, not 0 */
 	orb	%al, %cl
 	movb	0xc(%ebp), %dl		/* drive */
@@ -406,7 +463,8 @@ disk_use_standard_bios:
 	/* prot_to_real will set %es to 0, so must set it ourselves
 	   after it is called */
 	movb	0x18(%ebp), %bl		/* number of sectors */
-	movb	0x8(%ebp), %bh		/* bios disk subfunction */
+	movb	0x8(%ebp), %bh		/* read=0, write=1 */
+	addb	$0x2, %bh		/* convert to subfunction */
 	shll	$16, %ebx		/* shift num sect. and subfunction */
 	movw	0x1c(%ebp), %bx		/* segment */
 
@@ -528,6 +586,7 @@ probe_loop:
 	movb	$1, %dh
 	movb	$79, %ch
 
+	xorb	%bh, %bh		/* no BIOS extensions */
 	data32
 	jmp	probe_success
 
@@ -535,7 +594,27 @@ probe_values:
 	.byte	36, 18, 15, 9, 0
 
 hard_drive:
-	movb	$0x8, %ah		/* ask for disk info */
+	/* Check for LBA. */
+	movb	$0x41, %ah
+	movw	$0x55aa, %bx
+	int	$0x13			/* int 13 extensions install check */
+
+	data32
+	jc	1f			/* invalid function */
+	cmpw	$0xaa55, %bx
+	data32
+	jnz	1f			/* failed magic */
+
+	andb	$1, %cx
+	data32
+	jnz	1f			/* LBA not supported */
+
+	/* Wahoo!  Got LBA! */
+	movb	$0x1, %bh
+	jmp	2f
+
+1:	xorb	%bh, %bh		/* Too bad, no LBA */
+2:	movb	$0x8, %ah		/* ask for disk info */
 	int	$0x13
 
 	data32
@@ -546,18 +625,24 @@ hard_drive:
 
 probe_success:
 	/*
-	 * form a longword representing all this gunk:
+	 * form a dword representing all this gunk:
-	 *       6 bit zero
+	 *       4 bit BIOS extension (0 = none, 1 = LBA)
-	 *	10 bit cylinder
+	 *	12 bit cylinder
 	 *	 8 bit head
 	 *	 8 bit sector
 	 */
-	movb	%cl, %al		/* Upper two bits of cylinder count */
+	movb	%bh, %ah		/* restore BIOS extensions bits */
-	andl	$192,%eax
+
-	addr32
+	movb	%dh, %al		/* bits 10,11 of cylinder count */
-	leal	0(,%eax,4),%eax		/* << 2 */
+	andb	$0xc0, %eax
+	shlw	$2, %ax			/* << 2 */
+	movb	%cl, %al		/* bits 8,9 of cylinder count */
+	andb	$0xc0, %al
+	shlw	$2, %ax			/* << 2 */
 	movb	%ch, %al		/* Lower 8 bits */
-	sall	$16,%eax		/* << 16 */
+	shll	$16, %eax		/* << 16 */
+
+	andb	$0x3f, %ah		/* mask of cylinder gunk */
 	movb	%dh, %ah		/* max head */
 	andb	$0x3f, %cl		/* mask of cylinder gunk */
 	movb	%cl, %al		/* max sector (and # sectors) */

shared_src/cmdline.c

@@ -450,11 +450,11 @@ returnit:
 		      buf_track = -1;
 
 		      if (!errnum
-			  && (biosdisk(BIOSDISK_SUBFUNC_WRITE,
+			  && (biosdisk(BIOSDISK_WRITE,
 				       dest_drive, dest_geom,
 				       dest_sector, 1, (BOOTSEC_LOCATION>>4))
 			      || (write_stage2_sect
-				  && biosdisk(BIOSDISK_SUBFUNC_WRITE,
+				  && biosdisk(BIOSDISK_WRITE,
 					      current_drive, buf_geom,
 					      stage2_sect, 1, SCRATCHSEG))))
 			  errnum = ERR_WRITE;

shared_src/disk_io.c

@@ -86,6 +86,7 @@ rawread (int drive, int sector, int byte_offset, int byte_len, int addr)
       if (buf_drive != drive)
 	{
 	  buf_geom = get_diskinfo (drive);
+	  printf ("buf_geom = 0x%x\n", buf_geom); /* FIXME */
 	  buf_drive = drive;
 	  buf_track = -1;
 	}
@@ -118,7 +119,7 @@ rawread (int drive, int sector, int byte_offset, int byte_len, int addr)
 	      bufaddr = BUFFERADDR + byte_offset;
 	    }
 
-	  if (bios_err = biosdisk (BIOSDISK_SUBFUNC_READ, drive, buf_geom,
+	  if (bios_err = biosdisk (BIOSDISK_READ, drive, buf_geom,
 				   read_start, read_len, BUFFERSEG))
 	    {
 	      buf_track = -1;
@@ -132,7 +133,7 @@ rawread (int drive, int sector, int byte_offset, int byte_len, int addr)
 		   *  required sector(s) rather than failing completely.
 		   */
 		  if (slen > num_sect
-		      || biosdisk (BIOSDISK_SUBFUNC_READ, drive, buf_geom,
+		      || biosdisk (BIOSDISK_READ, drive, buf_geom,
 				   sector, slen, BUFFERSEG))
 		    errnum = ERR_READ;
 
@@ -270,7 +271,7 @@ make_saved_active (void)
 
 	  buf_track = -1;
 
-	  if (biosdisk (BIOSDISK_SUBFUNC_WRITE, saved_drive, buf_geom,
+	  if (biosdisk (BIOSDISK_WRITE, saved_drive, buf_geom,
 			0, 1, SCRATCHSEG))
 	    {
 	      errnum = ERR_WRITE;

shared_src/shared.h

@@ -48,8 +48,8 @@
 /*
  *  BIOS disk defines
  */
-#define BIOSDISK_SUBFUNC_READ       0x2
+#define BIOSDISK_READ		    0x0
-#define BIOSDISK_SUBFUNC_WRITE      0x3
+#define BIOSDISK_WRITE		    0x1
 #define BIOSDISK_ERROR_GEOMETRY     0x100
 
 /*
@@ -287,7 +287,7 @@ __attribute__ ((noreturn));
 
 /* low-level disk I/O */
      int get_diskinfo (int drive);
-     int biosdisk (int subfunc, int drive, int geometry,
+     int biosdisk (int read, int drive, int geometry,
 		   int sector, int nsec, int segment);
      void stop_floppy (void);