2005-02-15 Yoshinori K. Okuji <okuji@enbug.org>

  * stage2/builtins.c (install_func): If DEST_DRIVE is a hard
  disk, enable the workaround in Stage 1 by replacing the jmp
  with double nop's.

  * stage1/stage1.h (STAGE1_BOOT_DRIVE_CHECK): New macro.
  (STAGE1_BOOT_DRIVE_MASK): Removed.

  * stage1/stage1.S (boot_drive_check): New label. This implements
  a different workaround for buggy BIOSes which don't pass boot
  drive correctly. This is effective for BIOSes which pass a value
  without the seventh bit (0x80).
  (boot_drive_mask): Removed.

diff --git a/ChangeLog b/ChangeLog
index 7f6b386c1baa819e4a74762e928b358962130ee2..7e12dc2ebca14692bdbd509bc8c6dc133f75a663 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,18 @@
+2005-02-15  Yoshinori K. Okuji  <okuji@enbug.org>
+
+       * stage2/builtins.c (install_func): If DEST_DRIVE is a hard
+       disk, enable the workaround in Stage 1 by replacing the jmp
+       with double nop's.
+
+       * stage1/stage1.h (STAGE1_BOOT_DRIVE_CHECK): New macro.
+       (STAGE1_BOOT_DRIVE_MASK): Removed.
+
+       * stage1/stage1.S (boot_drive_check): New label. This implements
+       a different workaround for buggy BIOSes which don't pass boot
+       drive correctly. This is effective for BIOSes which pass a value
+       without the seventh bit (0x80).
+       (boot_drive_mask): Removed.
+
 2005-02-03  Yoshinori K. Okuji  <okuji@enbug.org>
 
        * grub/asmstub.c (console_current_color): Make it global as

diff --git a/NEWS b/NEWS
index fd75e7dc039fc2796a8d6580bc59941979ab15a5..a722101f91a9a2f13fe386f855b00138391f190c 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -1,5 +1,11 @@
 NEWS - list of user-visible changes between releases of GRUB
 
+New:
+* Fix the prototypes and the definitions of nested functions. This was
+  required for gcc-4.
+* Implement a more robust workaround for buggy BIOSes which don't pass
+  boot drive correctly (notably for HP Vectra).
+
 New in 0.96 - 2005-01-30:
 * The command "fallback" supports mutiple fallback entries.
 * The command "savedefault" supports an optional argument which

diff --git a/stage1/stage1.S b/stage1/stage1.S
index 50c63e4ae6370ca1da5537bea60a0a40fabed0a1..985963dd1ec690633e3ed14e6197de9ff07367fc 100644 (file)
--- a/stage1/stage1.S
+++ b/stage1/stage1.S
@@ -108,12 +108,18 @@ after_BPB:
 
        /*
         * This is a workaround for buggy BIOSes which don't pass boot
-        * drive correctly. If GRUB is installed into a HDD, do
-        * "orb $0x80, %dl", otherwise "orb $0x00, %dl" (i.e. nop).
+        * drive correctly. If GRUB is installed into a HDD, check if
+        * DL is masked correctly. If not, assume that the BIOS passed
+        * a bogus value and set DL to 0x80, since this is the only
+        * possible boot drive. If GRUB is installed into a floppy,
+        * this does nothing (only jump).
         */
-       .byte   0x80, 0xca
-boot_drive_mask:
-       .byte   0x00
+boot_drive_check:      
+       jmp     1f
+       testb   $0x80, %dl
+       jnz     1f
+       movb    $0x80, %dl
+1:     
 
        /*
         * ljmp to the next instruction because some bogus BIOSes

diff --git a/stage1/stage1.h b/stage1/stage1.h
index 4205a5fd87a25c8850e4d4b1d6bf85dd6ed493ed..d232ade11378b9cbbc135a383083faebbb84ed00 100644 (file)
--- a/stage1/stage1.h
+++ b/stage1/stage1.h
@@ -51,8 +51,8 @@
 /* The offset of STAGE2_SEGMENT.  */
 #define STAGE1_STAGE2_SEGMENT  0x48
 
-/* The offset of BOOT_DRIVE_MASK.  */
-#define STAGE1_BOOT_DRIVE_MASK 0x4d
+/* The offset of BOOT_DRIVE_CHECK.  */
+#define STAGE1_BOOT_DRIVE_CHECK        0x4b
 
 /* The offset of a magic number used by Windows NT.  */
 #define STAGE1_WINDOWS_NT_MAGIC        0x1b8

diff --git a/stage2/builtins.c b/stage2/builtins.c
index df98a1e7a01645e8bbee62d6afcf97b9ff23718d..3e08a8632c3eb9f0c7994de8d29811782dcdd919 100644 (file)
--- a/stage2/builtins.c
+++ b/stage2/builtins.c
@@ -1952,11 +1952,13 @@ install_func (char *arg, int flags)
   /* Set the "force LBA" flag.  */
   *((unsigned char *) (stage1_buffer + STAGE1_FORCE_LBA)) = is_force_lba;
 
-  /* Set the boot drive mask. This is a workaround for buggy BIOSes which
-     don't pass boot drive correctly. Instead, they pass 0x00 even when
-     booted from 0x80.  */
-  *((unsigned char *) (stage1_buffer + STAGE1_BOOT_DRIVE_MASK))
-    = (dest_drive & BIOS_FLAG_FIXED_DISK);
+  /* If DEST_DRIVE is a hard disk, enable the workaround, which is
+     for buggy BIOSes which don't pass boot drive correctly. Instead,
+     they pass 0x00 or 0x01 even when booted from 0x80.  */
+  if (dest_drive & BIOS_FLAG_FIXED_DISK)
+    /* Replace the jmp (2 bytes) with double nop's.  */
+    *((unsigned short *) (stage1_buffer + STAGE1_BOOT_DRIVE_CHECK))
+      = 0x9090;
   
   /* Read the first sector of Stage 2.  */
   disk_read_hook = disk_read_savesect_func;