/sbin/grub works

ChangeLog

@@ -1,3 +1,48 @@
+1999-03-21  Gordon Matzigkeit  <gord@trick.fig.org>
+
+	* shared_src/boot.c (load_image): Make sure we use the mapped
+	address before actually writing data to memaddr.
+
+	* shared_src/char_io.c (get_cmdline): Only zero-terminate if there
+	were leading blanks.  This prevents accidental truncation of
+	commands.
+
+	* grub/asmstub.c (get_diskinfo): Cache device geometries as well
+	as file handles.
+	Use the Linux HDIO_GETGEO ioctl to make a better guess at hard
+	disk geometries.
+
+1999-03-16  Gordon Matzigkeit  <gord@trick.fig.org>
+
+	* shared_src/shared.h (geometry_t): Delete typedef, until we
+	actually use it.
+
+1999-03-16  OKUJI Yoshinori  <okuji@kuicr.kyoto-u.ac.jp>
+
+	* shared_src/asm.S (biosdisk): Use a structure for geometry
+	instead of a integer.
+	(get_diskinfo): Take a pointer to a geometry structure as the
+	second argument, and fill a geometry in it. Return 1 if an error
+	occurs, otherwise return 0.
+	* shared_src/boot.c (bsd_boot): Compute BIOS geometries for BSD.
+	* shared_src/cmdline.c (enter_cmdline): Declare dest_geom as
+	struct geometry.
+	* shared_src/disk_io.c (buf_geom): Declare as struct geometry.
+	* shared_src/filesys.h (SECTORS): Deleted.
+	(HEADS): Likewise.
+	(CYLINDERS): Likewise.
+	* shared_src/shared.h (BIOSDISK_FLAG_LBA_EXTENSION): New macro.
+	(struct geometry): New structure.
+	(buf_geom): Correct the prototype.
+	(get_diskinfo): Likewise.
+	(biosdisk): Likewise.
+
+1999-03-15  Gordon Matzigkeit  <gord@trick.fig.org>
+
+	* grub/asmstub.c (doit): Nested function to get a clean stack
+	frame while in grub_stage2.
+	Use different assembler magic.  From OKUJI Yoshinori.
+
 1999-03-14  Gordon Matzigkeit  <gord@trick.fig.org>
 
 	* shared_src/stage2.c (run_menu): Use A_REVERSE and A_NORMAL

NEWS

@@ -1,5 +1,9 @@
 NEWS - list of user-visible changes between releases of GRUB
 
+New:
+* The /sbin/grub stage2 simulator now works for simple cases, and uses
+  the Linux HDIO_GETGEO ioctl to determine hard disk geometry.
+
 New in 0.5.91 - 1999-03-14, Gordon Matzigkeit:
 * LBA and preliminary AWARD BIOS disk extension support.
 * Started docs/grub.texi.

configure

@@ -692,7 +692,7 @@ fi
 PACKAGE=grub
 
 
-VERSION=0.5.91
+VERSION=0.5.92
 
 
 if test "`cd $srcdir && pwd`" != "`pwd`" && test -f $srcdir/config.status; then

debian/changelog

@@ -1,3 +1,9 @@
+grub (0.5.92) unstable; urgency=low
+
+  *
+
+ --
+
 grub (0.5.91) unstable; urgency=low
 
   * Added support for LBA mode and preliminary AWARD/AMI hard disk BIOS

grub/asmstub.c

@@ -39,10 +39,22 @@ int grub_stage2 (void);
 #include <assert.h>
 #include <stdio.h>
 
+#ifdef __linux__
+# include <sys/ioctl.h>		/* ioctl */
+# include <linux/hdreg.h>	/* HDIO_GETGEO */
+#endif /* __linux__ */
+
 /* Simulated memory sizes. */
 #define EXTENDED_MEMSIZE (4 * 1024 * 1024)	/* 4MB */
 #define CONVENTIONAL_MEMSIZE (640) /* 640kB */
 
+/* Simulated disk sizes. */
+#define DEFAULT_FD_CYLINDERS	80
+#define DEFAULT_FD_HEADS	2
+#define DEFAULT_FD_SECTORS	18
+#define DEFAULT_HD_CYLINDERS	620
+#define DEFAULT_HD_HEADS	128
+#define DEFAULT_HD_SECTORS	63
 
 unsigned long install_partition = 0x20000;
 unsigned long boot_drive = 0;
@@ -53,7 +65,7 @@ char config_file[] = "/boot/grub/menu.lst";
 char *grub_scratch_mem = 0;
 
 #define NUM_DISKS 256
-static FILE **disks = 0;
+static struct geometry *disks = 0;
 
 /* The main entry point into this mess. */
 int
@@ -65,6 +77,31 @@ grub_stage2 (void)
   int i;
   char *scratch, *simstack;
 
+  /* We need a nested function so that we get a clean stack frame,
+     regardless of how the code is optimized. */
+  static volatile void doit ()
+  {
+    /* Make sure our stack lives in the simulated memory area. */
+    asm volatile ("movl %%esp, %0\n\tmovl %1, %%esp\n"
+		  : "&=r" (realstack) : "r" (simstack));
+
+    /* FIXME: Do a setjmp here for the stop command. */
+    if (1)
+      {
+	/* Actually enter the generic stage2 code. */
+	status = 0;
+	init_bios_info ();
+      }
+    else
+      {
+	/* Somebody aborted. */
+	status = 1;
+      }
+
+    /* Replace our stack before we use any local variables. */
+    asm volatile ("movl %0, %%esp\n" : : "r" (realstack));
+  }
+
   assert (grub_scratch_mem == 0);
   scratch = malloc (0x100000 + EXTENDED_MEMSIZE + 15);
   assert (scratch);
@@ -93,32 +130,9 @@ grub_stage2 (void)
   keypad (stdscr, TRUE);
 #endif
 
-  /* Make sure our stack lives in the simulated memory area. */
+  /* Set our stack, and go for it. */
-  simstack = (char *) RAW_ADDR (PROTSTACKINIT);
+  simstack = (char *) PROTSTACKINIT;
-#ifdef SIMULATE_STACK
+  doit ();
-  __asm __volatile ("movl %%esp, %0;" : "=d" (realstack));
-  __asm __volatile ("movl %0, %%esp" :: "d" (simstack));
-#endif
-
-  {
-    /* FIXME: Do a setjmp here for the stop command. */
-    if (1)
-      {
-	/* Actually enter the generic stage2 code. */
-	status = 0;
-	init_bios_info ();
-      }
-    else
-      {
-	/* Somebody aborted. */
-	status = 1;
-      }
-  }
-
-#ifdef SIMULATE_STACK
-  /* Replace our stack before we use any local variables. */
-  __asm __volatile ("movl %0, %%esp" :: "d" (realstack));
-#endif
 
 #ifdef HAVE_LIBCURSES
   endwin ();
@@ -126,8 +140,8 @@ grub_stage2 (void)
 
   /* Close off the file pointers we used. */
   for (i = 0; i < NUM_DISKS; i ++)
-    if (disks[i])
+    if (disks[i].flags)
-      fclose (disks[i]);
+      fclose ((FILE *) disks[i].flags);
 
   /* Release memory. */
   free (disks);
@@ -352,47 +366,107 @@ set_attrib (int attr)
 /* Low-level disk I/O.  Our stubbed version just returns a file
    descriptor, not the actual geometry. */
 int
-get_diskinfo (int drive)
+get_diskinfo (int drive, struct geometry *geometry)
 {
-  /* The unpartitioned device name: /dev/XdX */
+  /* FIXME: this function is truly horrid.  We try opening the device,
-  char devname[9];
+     then severely abuse the GEOMETRY->flags field to pass a file
+     pointer to biosdisk.  Thank God nobody's looking at this comment,
+     or my reputation would be ruined. --Gord */
 
   /* See if we have a cached device. */
-  if (disks[drive])
+  if (! disks[drive].flags)
-    return (int) disks[drive];
+    {
+      /* The unpartitioned device name: /dev/XdX */
+      char devname[9];
 
-  /* Try opening the drive device. */
+      /* Try opening the drive device. */
-  strcpy (devname, "/dev/");
+      strcpy (devname, "/dev/");
-  if (drive & 0x80)
-    devname[5] = 'h';
-  else
-    devname[5] = 'f';
-  devname[6] = 'd';
 
-  /* Check to make sure we don't exceed /dev/hdz. */
+#ifdef __linux__
-  devname[7] = (drive & 0x7f) + 'a';
+      /* Linux uses /dev/hda, and /dev/sda, but /dev/fd0.  Go figure. */
-  if (devname[7] > 'z')
+      if (drive & 0x80)
-    return 0;
+	{
-  devname[8] = '\0';
+	  /* Check to make sure we don't exceed /dev/hdz. */
+	  devname[5] = 'h';
+	  devname[7] = 'a' + (drive & 0x7f);
+	  if (devname[7] > 'z')
+	    return -1;
+	}
+      else
+	{
+	  devname[5] = 'f';
+	  devname[7] = '0' + drive;
+	  if (devname[7] > '9')
+	    return -1;
+	}
+#else /* ! __linux__ */
+      if (drive & 0x80)
+	devname[5] = 'h';
 
-  /* Open read/write, or read-only if that failed. */
+      devname[7] = '0' + drive;
-  disks[drive] = fopen (devname, "r+");
+      if (devname[7] > '9')
-  if (! disks[drive])
+	return -1;
-    disks[drive] = fopen (devname, "r");
+#endif /* __linux__ */
 
-  return (int) disks[drive];
+      devname[6] = 'd';
+      devname[8] = '\0';
+
+      /* Open read/write, or read-only if that failed. */
+      disks[drive].flags = (int) fopen (devname, "r+");
+      if (! disks[drive].flags)
+	disks[drive].flags = (int) fopen (devname, "r");
+
+      if (disks[drive].flags)
+	{
+#ifdef __linux__
+	  struct hd_geometry hdg;
+	  if (! ioctl (fileno ((FILE *) disks[drive].flags),
+		       HDIO_GETGEO, &hdg))
+	    {
+	      /* Got the geometry, so save it. */
+	      disks[drive].cylinders = hdg.cylinders;
+	      disks[drive].heads = hdg.heads;
+	      disks[drive].sectors = hdg.sectors;
+	    }
+	  else
+	    /* FIXME: should have some other alternatives before using
+	       arbitrary defaults. */
+#endif
+	  /* Set some arbitrary defaults. */
+	  if (drive & 0x80)
+	    {
+	      /* Hard drive. */
+	      disks[drive].cylinders = DEFAULT_HD_CYLINDERS;
+	      disks[drive].heads = DEFAULT_HD_HEADS;
+	      disks[drive].sectors = DEFAULT_HD_SECTORS;
+	    }
+	  else
+	    {
+	      /* Floppy. */
+	      disks[drive].cylinders = DEFAULT_FD_CYLINDERS;
+	      disks[drive].heads = DEFAULT_FD_HEADS;
+	      disks[drive].sectors = DEFAULT_FD_SECTORS;
+	    }
+	}
+    }
+
+  if (! disks[drive].flags)
+    return -1;
+
+  *geometry = disks[drive];
+  return 0;
 }
 
 int
-biosdisk (int subfunc, int drive, int geometry,
+biosdisk (int subfunc, int drive, struct geometry *geometry,
 	  int sector, int nsec, int segment)
 {
   char *buf;
   FILE *fp;
 
   /* Get the file pointer from the geometry, and make sure it matches. */
-  fp = (FILE *) geometry;
+  fp = (FILE *) geometry->flags;
-  if (! fp || fp != disks[drive])
+  if (! fp || fp != (FILE *) disks[drive].flags)
     return BIOSDISK_ERROR_GEOMETRY;
 
   /* Seek to the specified location. */

shared_src/asm.S

@@ -352,10 +352,12 @@ ENTRY(biosdisk)
 	push	%ecx
 	push	%edx
 	push	%esi
+	push	%edi
 
 	/* Check whether we have LBA. */
-	movb	0x13(%ebp), %al
+	movl	0x10(%ebp), %eax
-	andb	$0x10, %al
+	andb	0xc(%eax), %eax
+	andl	$BIOSDISK_FLAG_LBA_EXTENSION, %eax
 	jz	disk_compute_args	/* nope. */
 
 	/* set up disk address packet for extended calls (LBA mode) */
@@ -416,39 +418,37 @@ ENTRY(biosdisk)
 	/* either failed, or a floppy, so try standard BIOS calls */
 disk_compute_args:
 	/*
-	 * GEOMETRY is a longword representing the BIOS geometry:
+	 * GEOMETRY is a structure representing the BIOS geometry:
-	 *       4 bit BIOS extension (0 = none, 1 = LBA)
+	 *      32 bit flags      (bytes 12-15)
-	 *	12 bit cylinder   (bytes 2 & 3)
+	 *	32 bit cylinders  (bytes 8-11)
-	 *	 8 bit head       (byte 1)
+	 *	32 bit heads      (bytes 4-7)
-	 *	 8 bit sector     (byte 0)
+	 *	32 bit sectors    (bytes 0-3)
 	 */
 
 	/* set up original sector number */
 	xorl	%edx, %edx
 	movl	0x14(%ebp), %eax
 
+	/* get the pointer to GEOMETRY */
+	movl	0x10(%ebp), %edi
+
 	/* get sector offset, place in %ecx */
-	xorl	%ebx, %ebx
+	movl	0x8(%edi), %ebx
-	movb	0x10(%ebp), %bl
 	divl	%ebx
 	movl	%edx, %ecx
 
 	/* get track offset (head number) in %edx,
 	   and cylinder offset in %eax */
 	xorl	%edx, %edx
-	xorl	%ebx, %ebx
+	movl	0x4(%edi), %ebx
-	movb	0x11(%ebp), %bl
-	inc	%ebx
 	divl	%ebx
 
 	/* check cylinder offset, is there a geometry problem here? */
-	movl	0x10(%ebp), %ebx
+	movl	(%edi), %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
+	jl	disk_use_standard_bios
 
 	movl	$BIOSDISK_ERROR_GEOMETRY, %eax
 	jmp	disk_exit_32
@@ -538,6 +538,7 @@ disk_exit_16:
 	movb	%bl, %al		/* return value in %eax */
 
 disk_exit_32:
+	pop	%edi
 	pop	%esi
 	pop	%edx
 	pop	%ecx
@@ -549,8 +550,9 @@ disk_exit_32:
 
 /*
  *
- * get_diskinfo(drive):  return a word that represents the
+ * get_diskinfo(drive, geometry):  return a structure that represents the
- *	max number of sectors and heads and cylinders for this drive
+ *	max number of sectors and heads and cylinders for DRIVE in GEOMETRY.
+ *	If an error occures, return non-zero, otherwise return zero.
  *
  */
 
@@ -633,11 +635,12 @@ hard_drive:
 	jz	1f			/* LBA not supported */
 
 	/* Wahoo!  Got LBA! */
-	movb	$0x1, %bh
+	movl	$BIOSDISK_FLAG_LBA_EXTENSION, %edi
+	/* FIXME: Should use INT 13 AH=42h */
 	data32
 	jmp	2f
 
-1:	xorb	%bh, %bh		/* Too bad, no LBA */
+1:	xorl	%edi, %edi		/* Too bad, no LBA */
 2:	movb	$0x8, %ah		/* ask for disk info */
 	int	$0x13
 
@@ -649,33 +652,36 @@ hard_drive:
 
 probe_success:
 	/*
-	 * form a dword representing all this gunk:
+	 * Store the information for CHS and BIOS extension to registers:
-	 *       4 bit BIOS extension (0 = none, 1 = LBA)
+	 *      32 bit BIOS extension -> edi
-	 *	12 bit cylinder
+	 *	32 bit cylinder       -> ebx
-	 *	 8 bit head
+	 *	32 bit head           -> ecx
-	 *	 8 bit sector
+	 *	32 bit sector         -> edx
 	 */
-	movb	%bh, %ah		/* restore BIOS extensions bits */
-
 #ifdef AWARD_INT13_EXTENSIONS
 	movb	%dh, %al		/* bits 10,11 of cylinder count */
 	andb	$0xc0, %al
-#endif
 	shlw	$2, %ax			/* << 2 */
+#endif
 	movb	%cl, %al		/* bits 8,9 of cylinder count */
 	andb	$0xc0, %al
 	shlw	$2, %ax			/* << 2 */
 	movb	%ch, %al		/* Lower 8 bits */
+	movswl	%ax, %ebx		/* max cylinder */
+	incl	%ebx			/* number of cylinders */
 	shll	$16, %eax		/* << 16 */
 
 #ifdef AWARD_INT13_EXTENSIONS
 	andb	$0x3f, %dh		/* mask off cylinder gunk */
 #endif
-	movb	%dh, %ah		/* max head */
+	movb	%dh, %al		/* max head */
-	andb	$0x3f, %cl		/* mask off cylinder gunk */
+	
-	movb	%cl, %al		/* max sector (and # sectors) */
+	andb	$0x3f, %cl		/* mask off cylinder gunk */
+	movsbl	%cl, %edx		/* max sector (and # sectors) */
+
+	movsbl	%al, %ecx
+	incl	%ecx			/* number of heads */
 
-	movl	%eax, %ebx		/* save return value */
 	data32
 	jmp	got_drive
 
@@ -684,18 +690,37 @@ probe_failed:
 	 * Urk.  Call failed.  It is not supported for floppies by old
 	 * BIOSes, but it should work for all hard drives!!
 	 *
-	 * Return a 0 here...  presume there is no drive present.  ????
+	 * Return a 1 here...  presume there is no drive present.  ????
 	 */
 
-	movl	$0, %ebx		/* not present value */
+	data32
+	call	EXT_C(real_to_prot)
+	.code32
 
+	movl	$1, %eax
+	popl	%esi
+	popl	%edi
+	popl	%edx
+	popl	%ecx
+	popl	%ebx
+	popl	%ebp
+
+	ret
+
+	.code16
 got_drive:
 	data32
 	call	EXT_C(real_to_prot)	/* back to protected mode */
 	.code32
 
-	/* set up return in correct register */
+	/* set up return structure */
-	movl	%ebx, %eax
+	movl	0x0c(%ebp), %eax
+	movl	%ebx, (%eax)
+	movl	%ecx, 0x04(%eax)
+	movl	%edx, 0x08(%eax)
+	movl	%edi, 0x0c(%eax)
+	
+	xorl	%eax, %eax
 
 	popl	%esi
 	popl	%edi

shared_src/boot.c

@@ -381,6 +381,7 @@ load_image (void)
 	      loaded++;
 
 	      /* load the segment */
+	      memaddr = RAW_ADDR (memaddr);
 	      if (memcheck (memaddr, memsiz)
 		  && grub_read ((char *) memaddr, filesiz) == filesiz)
 		{
@@ -532,7 +533,18 @@ bsd_boot (int type, int bootdev)
       bi.bi_n_bios_used = 0;	/* this field is apparently unused */
 
       for (i = 0; i < N_BIOS_GEOM; i++)
-	bi.bi_bios_geom[i] = get_diskinfo (i + 0x80);
+	{
+	  struct geometry geom;
+
+	  /* XXX Should check the return value.  */
+	  get_diskinfo (i + 0x80, &geom);
+	  /* FIXME: If HEADS or SECTORS is greater than 255, then this will
+	     break the geometry information. That is a drawback of BSD
+	     but not of GRUB.  */
+	  bi.bi_bios_geom[i] = (((geom.cylinders - 1) << 16)
+				+ (((geom.heads - 1) & 0xff) << 8)
+				+ (geom.sectors & 0xff));
+	}
 
       bi.bi_size = sizeof (struct bootinfo);
       bi.bi_memsizes_valid = 1;

shared_src/char_io.c

@@ -398,9 +398,10 @@ get_cmdline (char *prompt, char *commands, char *cmdline, int maxlen)
 	  lpos++;
 	}
       while (cmdline[lpos]);
-    }
 
-  cmdline[c] = 0;
+      /* Zero-terminate the string. */
+      cmdline[c] = 0;
+    }
 
   return 0;
 }
@@ -562,13 +563,16 @@ strstr (char *s1, char *s2)
 int
 memcheck (int start, int len)
 {
-  /* FIXME: fails when used with addresses on our stack. */
+  /* FIXME: Don't bother checking memory for now, since our globals
+     are out of range. */
+#ifndef GRUB_UTIL
   if ((start < RAW_ADDR (0x1000)) ||
       (start < RAW_ADDR (0x100000) &&
        RAW_ADDR (mbi.mem_lower * 1024) < (start + len)) ||
       (start >= RAW_ADDR (0x100000) &&
        RAW_ADDR (mbi.mem_upper * 1024) < ((start - 0x100000) + len)))
     errnum = ERR_WONT_FIT;
+#endif /* GRUB_UTIL */
 
   return (!errnum);
 }

shared_src/cmdline.c

@@ -372,7 +372,8 @@ returnit:
 	  set_device (dest_dev) && open_partition () &&
 	  devread (0, 0, SECTOR_SIZE, old_sect))
 	{
-	  int dest_drive = current_drive, dest_geom = buf_geom;
+	  int dest_drive = current_drive;
+	  struct geometry dest_geom = buf_geom;
 	  int dest_sector = part_start, i;
 
 #ifndef NO_DECOMPRESSION
@@ -466,11 +467,11 @@ returnit:
 
 		      if (!errnum
 			  && (biosdisk(BIOSDISK_WRITE,
-				       dest_drive, dest_geom,
+				       dest_drive, &dest_geom,
 				       dest_sector, 1, (BOOTSEC_LOCATION>>4))
 			      || (write_stage2_sect
 				  && biosdisk(BIOSDISK_WRITE,
-					      current_drive, buf_geom,
+					      current_drive, &buf_geom,
 					      stage2_sect, 1, SCRATCHSEG))))
 			  errnum = ERR_WRITE;
 		    }

shared_src/disk_io.c

@@ -78,7 +78,7 @@ int current_slice;
 /* disk buffer parameters */
 int buf_drive = -1;
 int buf_track;
-int buf_geom;
+struct geometry buf_geom;
 
 /* filesystem common variables */
 int filepos;
@@ -103,26 +103,24 @@ rawread (int drive, int sector, int byte_offset, int byte_len, char *buf)
        */
       if (buf_drive != drive)
 	{
-	  buf_geom = get_diskinfo (drive);
+	  if (get_diskinfo (drive, &buf_geom))
+	    {
+	      errnum = ERR_NO_DISK;
+	      return 0;
+	    }
 	  buf_drive = drive;
 	  buf_track = -1;
 	}
 
-      if (buf_geom == 0)
-	{
-	  errnum = ERR_NO_DISK;
-	  return 0;
-	}
-
       /*  Get first sector of track  */
-      soff = sector % SECTORS (buf_geom);
+      soff = sector % buf_geom.sectors;
       track = sector - soff;
-      num_sect = SECTORS (buf_geom) - soff;
+      num_sect = buf_geom.sectors - soff;
       bufaddr = BUFFERADDR + (soff * SECTOR_SIZE) + byte_offset;
 
       if (track != buf_track)
 	{
-	  int bios_err, read_start = track, read_len = SECTORS (buf_geom);
+	  int bios_err, read_start = track, read_len = buf_geom.sectors;
 
 	  /*
 	   *  If there's more than one read in this entire loop, then
@@ -136,7 +134,7 @@ rawread (int drive, int sector, int byte_offset, int byte_len, char *buf)
 	      bufaddr = BUFFERADDR + byte_offset;
 	    }
 
-	  bios_err = biosdisk (BIOSDISK_READ, drive, buf_geom,
+	  bios_err = biosdisk (BIOSDISK_READ, drive, &buf_geom,
 			       read_start, read_len, BUFFERSEG);
 	  if (bios_err)
 	    {
@@ -151,7 +149,7 @@ rawread (int drive, int sector, int byte_offset, int byte_len, char *buf)
 		   *  required sector(s) rather than failing completely.
 		   */
 		  if (slen > num_sect
-		      || biosdisk (BIOSDISK_READ, drive, buf_geom,
+		      || biosdisk (BIOSDISK_READ, drive, &buf_geom,
 				   sector, slen, BUFFERSEG))
 		    errnum = ERR_READ;
 
@@ -293,7 +291,7 @@ make_saved_active (void)
 
 	  buf_track = -1;
 
-	  if (biosdisk (BIOSDISK_WRITE, saved_drive, buf_geom,
+	  if (biosdisk (BIOSDISK_WRITE, saved_drive, &buf_geom,
 			0, 1, SCRATCHSEG))
 	    {
 	      errnum = ERR_WRITE;
@@ -406,7 +404,7 @@ real_open_partition (int flags)
   bsd_evil_hack = 0;
   current_slice = 0;
   part_start = 0;
-  part_length = SECTORS (buf_geom) * HEADS (buf_geom) * CYLINDERS (buf_geom);
+  part_length = buf_geom.sectors * buf_geom.heads * buf_geom.cylinders;
 
   if (current_drive & 0x80)
     {
@@ -900,6 +898,7 @@ print_completions (char *filename)
 	    {
 	      /* disk completions */
 	      int disk_no, i, j;
+	      struct geometry geom;
 
 	      printf (" Possible disks are: ");
 
@@ -908,8 +907,8 @@ print_completions (char *filename)
 		  for (j = 0; j < 8; j++)
 		    {
 		      disk_no = (i * 0x80) + j;
-		      if ((disk_choice || disk_no == current_drive)
+		      if ((disk_choice || disk_no == current_drive) &&
-			  && get_diskinfo (disk_no))
+			  ! get_diskinfo (disk_no, &geom))
 			printf (" %cd%d", (i ? 'h' : 'f'), j);
 		    }
 		}

shared_src/filesys.h

@@ -21,10 +21,6 @@
 
 #include "pc_slice.h"
 
-#define SECTORS(geom)    ( (geom) & 0xFF )
-#define HEADS(geom)      ( ( ( (geom) >> 8 ) & 0xFF ) + 1 )
-#define CYLINDERS(geom)  ( ( ( (geom) >> 16 ) & 0x3FF ) + 1 )
-
 /*
  *  Default to all functioning filesystems enabled
  */

shared_src/shared.h

@@ -58,6 +58,7 @@ extern char *grub_scratch_mem;
 #define BIOSDISK_READ		    0x0
 #define BIOSDISK_WRITE		    0x1
 #define BIOSDISK_ERROR_GEOMETRY     0x100
+#define BIOSDISK_FLAG_LBA_EXTENSION 0x1
 
 /*
  *  This is the filesystem (not raw device) buffer.
@@ -304,6 +305,19 @@ extern int fsys_type;
 extern int block_file;
 #endif /* NO_BLOCK_FILES */
 
+/* The information for a disk geometry */
+struct geometry
+{
+  /* The number of cylinders */
+  unsigned long cylinders;
+  /* The number of heads */
+  unsigned long heads;
+  /* The number of sectors */
+  unsigned long sectors;
+  /* Flags */
+  unsigned long flags;
+};
+
 extern long part_start;
 extern long part_length;
 
@@ -311,7 +325,7 @@ extern int current_slice;
 
 extern int buf_drive;
 extern int buf_track;
-extern int buf_geom;
+extern struct geometry buf_geom;
 
 /* these are the current file position and maximum file position */
 extern int filepos;
@@ -418,8 +432,8 @@ int checkkey (void);
 void set_attrib (int attr);
 
 /* Low-level disk I/O */
-int get_diskinfo (int drive);
+int get_diskinfo (int drive, struct geometry *geometry);
-int biosdisk (int read, int drive, int geometry,
+int biosdisk (int read, int drive, struct geometry *geometry,
 	      int sector, int nsec, int segment);
 void stop_floppy (void);
 
@@ -494,6 +508,6 @@ int load_image (void);
 int load_module (void);
 int load_initrd (void);
 
-void init_bios_info (void) __attribute__ ((noreturn));
+void init_bios_info (void);
 
 #endif /* ASM_FILE */