Move grub_chainloader_real_boot out of the kernel.

* grub-core/Makefile.am: Remove machine/loader.h. * grub-core/kern/i386/pc/startup.S (grub_chainloader_real_boot): Removed. * grub-core/lib/i386/relocator.c (grub_relocator16_esi): New extern variable. (grub_relocator16_keep_a20_enabled): Likewise. (grub_relocator16_boot): Fill new variables. * grub-core/lib/i386/relocator16.S: Add gate a20 handling. * grub-core/loader/i386/pc/chainloader.c (grub_chainloader_boot): Use relocator. (grub_chainloader_unload): Likewise. (grub_chainloader_cmd): Likewise. * include/grub/i386/pc/loader.h: Removed. * include/grub/i386/relocator.h (grub_relocator16_state): Add a20 and esi. All initialisers updated.
2011-11-12 15:46:50 +01:00 · 2011-11-12 15:46:50 +01:00 · 678f4b6713
commit 678f4b6713
parent 4626edf6a0 db1326f5fb
12 changed files with 168 additions and 69 deletions
--- a/20
+++ b/20
@ -1,3 +1,23 @@
+2011-11-12  Vladimir Serbinenko  <phcoder@gmail.com>
+
+	Move grub_chainloader_real_boot out of the kernel.
+
+	* grub-core/Makefile.am: Remove machine/loader.h.
+	* grub-core/kern/i386/pc/startup.S (grub_chainloader_real_boot):
+	Removed.
+	* grub-core/lib/i386/relocator.c (grub_relocator16_esi): New extern
+	variable.
+	(grub_relocator16_keep_a20_enabled): Likewise.
+	(grub_relocator16_boot): Fill new variables.
+	* grub-core/lib/i386/relocator16.S: Add gate a20 handling.
+	* grub-core/loader/i386/pc/chainloader.c (grub_chainloader_boot): Use
+	relocator.
+	(grub_chainloader_unload): Likewise.
+	(grub_chainloader_cmd): Likewise.
+	* include/grub/i386/pc/loader.h: Removed.
+	* include/grub/i386/relocator.h (grub_relocator16_state): Add a20
+	and esi. All initialisers updated.
+
 2011-11-12  Vladimir Serbinenko  <phcoder@gmail.com>
 2011-11-12  Colin Watson  <cjwatson@ubuntu.com>

--- a/grub-core/Makefile.am
+++ b/grub-core/Makefile.am
@ -83,7 +83,6 @@ KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/libgcc.h
 KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/memory.h

 if COND_i386_pc
-KERNEL_HEADER_FILES += $(top_builddir)/include/grub/machine/loader.h
 KERNEL_HEADER_FILES += $(top_builddir)/include/grub/machine/kernel.h
 KERNEL_HEADER_FILES += $(top_builddir)/include/grub/machine/pxe.h
 KERNEL_HEADER_FILES += $(top_builddir)/include/grub/machine/int.h
--- a/grub-core/kern/i386/pc/startup.S
+++ b/grub-core/kern/i386/pc/startup.S
@ -464,31 +464,6 @@ FUNCTION(grub_exit)
 	ljmp	$0xf000, $0xfff0
 	.code32

-/*
- *  void grub_chainloader_real_boot (int drive, void *part_addr)
- *
- *  This starts another boot loader.
- */
-
-FUNCTION(grub_chainloader_real_boot)
-	pushl	%edx
-	pushl	%eax
-
-	/* Turn off Gate A20 */
-	xorl	%eax, %eax
-	call	grub_gate_a20
-
-	/* set up to pass boot drive */
-	popl	%edx
-
-	/* ESI must point to a partition table entry */
-	popl	%esi
-
-	call	prot_to_real
-	.code16
-	ljmp	$0, $GRUB_MEMORY_MACHINE_BOOT_LOADER_ADDR
-	.code32
-
 /*
 * void grub_console_putchar (int c)
 *
--- a/grub-core/lib/i386/reboot.c
+++ b/grub-core/lib/i386/reboot.c
@ -49,6 +49,7 @@ grub_reboot (void)
  state.sp = 0;
  state.cs = segment;
  state.ip = 0;
+  state.a20 = 0;

  grub_stop_floppy ();
  
--- a/grub-core/lib/i386/relocator.c
+++ b/grub-core/lib/i386/relocator.c
@ -51,6 +51,9 @@ extern grub_uint16_t grub_relocator16_ss;
 extern grub_uint16_t grub_relocator16_sp;
 extern grub_uint32_t grub_relocator16_edx;
 extern grub_uint32_t grub_relocator16_ebx;
+extern grub_uint32_t grub_relocator16_esi;
+
+extern grub_uint16_t grub_relocator16_keep_a20_enabled;

 extern grub_uint8_t grub_relocator32_start;
 extern grub_uint8_t grub_relocator32_end;
@ -195,7 +198,8 @@ grub_relocator16_boot (struct grub_relocator *rel,
  void *relst;
  grub_relocator_chunk_t ch;

-  err = grub_relocator_alloc_chunk_align (rel, &ch, 0,
+  /* Put it higher than the byte it checks for A20 check.  */
+  err = grub_relocator_alloc_chunk_align (rel, &ch, 0x8010,
 					  0xa0000 - RELOCATOR_SIZEOF (16),
 					  RELOCATOR_SIZEOF (16), 16,
 					  GRUB_RELOCATOR_PREFERENCE_NONE);
@ -215,6 +219,9 @@ grub_relocator16_boot (struct grub_relocator *rel,

  grub_relocator16_ebx = state.ebx;
  grub_relocator16_edx = state.edx;
+  grub_relocator16_esi = state.esi;
+
+  grub_relocator16_keep_a20_enabled = state.a20;

  grub_memmove (get_virtual_current_address (ch), &grub_relocator16_start,
 		RELOCATOR_SIZEOF (16));
--- a/grub-core/lib/i386/relocator16.S
+++ b/grub-core/lib/i386/relocator16.S
@ -93,6 +93,85 @@ LOCAL(segment):
 	.word	0

 LOCAL(cont3):
+
+	/* movw imm16, %ax.  */
+	.byte	0xb8
+VARIABLE(grub_relocator16_keep_a20_enabled)
+	.word	0
+	test	%ax, %ax
+	jnz	LOCAL(gate_a20_done)
+
+	/* first of all, test if already in a good state */
+	call	LOCAL(gate_a20_check_state)
+	testb	%al, %al
+	jz	LOCAL(gate_a20_done)
+
+	/* second, try a BIOS call */
+	movw	$0x2400, %ax
+	int	$0x15
+
+	call	LOCAL(gate_a20_check_state)
+	testb	%al, %al
+	jz	LOCAL(gate_a20_done)
+
+	/*
+	 * In macbook, the keyboard test would hang the machine, so we move
+	 * this forward.
+	 */
+	/* fourth, try the system control port A */
+	inb	$0x92
+	andb	$(~0x03), %al
+	outb	$0x92
+
+	/* When turning off Gate A20, do not check the state strictly,
+	   because a failure is not fatal usually, and Gate A20 is always
+	   on some modern machines.  */
+	jmp	LOCAL(gate_a20_done)
+
+LOCAL(gate_a20_check_state):
+	/* iterate the checking for a while */
+	movw	$100, %cx
+1:
+	call	3f
+	testb	%al, %al
+	jz	2f
+	loop	1b
+2:
+	ret
+
+3:
+	xorw    %ax, %ax
+	movw    %ax, %ds
+	decw    %ax
+	movw    %ax, %es
+	xorw    %ax, %ax
+
+	movw	$0x8000, %ax
+	/* compare the byte at ADDR with that at 0x100000 + ADDR */
+	movw    %ax, %si
+	addw    $0x10, %ax
+	movw    %ax, %di
+
+	/* save the original byte in DL */
+	movb	%ds:(%si), %dl
+	movb	%es:(%di), %al
+	/* try to set one less value at ADDR */
+	movb	%al, %dh
+	decb	%dh
+	movb	%dh, %ds:(%si)
+	/* serialize */
+	outb	%al, $0x80
+	outb	%al, $0x80
+	/* obtain the value at 0x100000 + ADDR in CH */
+	movb	%es:(%di), %dh
+	/* this result is 1 if A20 is on or 0 if it is off */
+	subb	%dh, %al
+	xorb	$1, %al
+	/* restore the original */
+	movb	%dl, %es:(%di)
+	ret
+
+LOCAL(gate_a20_done):
 	/* we are in real mode now
 	 * set up the real mode segment registers : DS, SS, ES
 	 */
@ -132,6 +211,12 @@ VARIABLE(grub_relocator16_sp)
 	.word	0
 	movzwl	%ax, %esp

+	/* movw imm32, %eax.  */
+	.byte	0x66, 0xb8
+VARIABLE(grub_relocator16_esi)
+	.long	0
+	movl	%eax, %esi
+
 	/* movw imm32, %edx.  */
 	.byte	0x66, 0xba
 VARIABLE(grub_relocator16_edx)
--- a/grub-core/loader/i386/pc/chainloader.c
+++ b/grub-core/loader/i386/pc/chainloader.c
@ -18,7 +18,6 @@
 */

 #include <grub/loader.h>
-#include <grub/machine/loader.h>
 #include <grub/machine/chainloader.h>
 #include <grub/machine/memory.h>
 #include <grub/file.h>
@ -39,12 +38,14 @@
 #include <grub/mm.h>
 #include <grub/fat.h>
 #include <grub/ntfs.h>
+#include <grub/i386/relocator.h>

 GRUB_MOD_LICENSE ("GPLv3+");

 static grub_dl_t my_mod;
 static int boot_drive;
-static void *boot_part_addr;
+static grub_addr_t boot_part_addr;
+static struct grub_relocator *rel;

 typedef enum
  {
@ -55,16 +56,29 @@ typedef enum
 static grub_err_t
 grub_chainloader_boot (void)
 {
+  struct grub_relocator16_state state = { 
+    .edx = boot_drive,
+    .esi = boot_part_addr,
+    .ds = 0,
+    .es = 0,
+    .fs = 0,
+    .gs = 0,
+    .ss = 0,
+    .cs = 0,
+    .sp = GRUB_MEMORY_MACHINE_BOOT_LOADER_ADDR,
+    .ip = GRUB_MEMORY_MACHINE_BOOT_LOADER_ADDR,
+    .a20 = 0
+  };
  grub_video_set_mode ("text", 0, 0);
-  grub_chainloader_real_boot (boot_drive, boot_part_addr);

-  /* Never reach here.  */
-  return GRUB_ERR_NONE;
+  return grub_relocator16_boot (rel, state);
 }

 static grub_err_t
 grub_chainloader_unload (void)
 {
+  grub_relocator_unload (rel);
+  rel = NULL;
  grub_dl_unref (my_mod);
  return GRUB_ERR_NONE;
 }
@ -133,7 +147,12 @@ grub_chainloader_cmd (const char *filename, grub_chainloader_flags_t flags)
  grub_uint16_t signature;
  grub_device_t dev;
  int drive = -1;
-  void *part_addr = 0;
+  grub_addr_t part_addr = 0;
+  grub_uint8_t *bs, *ptable;
+
+  rel = grub_relocator_new ();
+  if (!rel)
+    goto fail;

  grub_dl_ref (my_mod);

@ -142,8 +161,25 @@ grub_chainloader_cmd (const char *filename, grub_chainloader_flags_t flags)
  if (! file)
    goto fail;

+  {
+    grub_relocator_chunk_t ch;
+    grub_err_t err;
+
+    err = grub_relocator_alloc_chunk_addr (rel, &ch, 0x7C00,
+					   GRUB_DISK_SECTOR_SIZE);
+    if (err)
+      goto fail;
+    bs = get_virtual_current_address (ch);
+    err = grub_relocator_alloc_chunk_addr (rel, &ch,
+					   GRUB_MEMORY_MACHINE_PART_TABLE_ADDR,
+					   64);
+    if (err)
+      goto fail;
+    ptable = get_virtual_current_address (ch);
+  }
+
  /* Read the first block.  */
-  if (grub_file_read (file, (void *) 0x7C00, GRUB_DISK_SECTOR_SIZE)
+  if (grub_file_read (file, bs, GRUB_DISK_SECTOR_SIZE)
      != GRUB_DISK_SECTOR_SIZE)
    {
      if (grub_errno == GRUB_ERR_NONE)
@ -153,7 +189,7 @@ grub_chainloader_cmd (const char *filename, grub_chainloader_flags_t flags)
    }

  /* Check the signature.  */
-  signature = *((grub_uint16_t *) (0x7C00 + GRUB_DISK_SECTOR_SIZE - 2));
+  signature = *((grub_uint16_t *) (bs + GRUB_DISK_SECTOR_SIZE - 2));
  if (signature != grub_le_to_cpu16 (0xaa55)
      && ! (flags & GRUB_CHAINLOADER_FORCE))
    {
@ -177,9 +213,8 @@ grub_chainloader_cmd (const char *filename, grub_chainloader_flags_t flags)
 	  if (p && grub_strcmp (p->partmap->name, "msdos") == 0)
 	    {
 	      disk->partition = p->parent;
-	      grub_disk_read (disk, p->offset, 446, 64,
-			      (void *) GRUB_MEMORY_MACHINE_PART_TABLE_ADDR);
-	      part_addr = (void *) (GRUB_MEMORY_MACHINE_PART_TABLE_ADDR
+	      grub_disk_read (disk, p->offset, 446, 64, ptable);
+	      part_addr = (GRUB_MEMORY_MACHINE_PART_TABLE_ADDR
 			   + (p->index << 4));
 	      disk->partition = p;
 	    }
--- a/grub-core/loader/i386/pc/freedos.c
+++ b/grub-core/loader/i386/pc/freedos.c
@ -56,7 +56,8 @@ grub_freedos_boot (void)
    .ss = GRUB_FREEDOS_STACK_SEGMENT,
    .sp = GRUB_FREEDOS_STACK_POINTER,
    .ebx = ebx,
-    .edx = 0
+    .edx = 0,
+    .a20 = 1
  };
  grub_video_set_mode ("text", 0, 0);

--- a/grub-core/loader/i386/pc/linux.c
+++ b/grub-core/loader/i386/pc/linux.c
@ -18,7 +18,6 @@
 */

 #include <grub/loader.h>
-#include <grub/machine/loader.h>
 #include <grub/file.h>
 #include <grub/err.h>
 #include <grub/device.h>
@ -61,6 +60,7 @@ grub_linux16_boot (void)
  state.sp = GRUB_LINUX_SETUP_STACK;
  state.cs = segment + 0x20;
  state.ip = 0;
+  state.a20 = 1;

  grub_video_set_mode ("text", 0, 0);

--- a/grub-core/loader/i386/pc/ntldr.c
+++ b/grub-core/loader/i386/pc/ntldr.c
@ -54,7 +54,8 @@ grub_ntldr_boot (void)
    .gs = 0,
    .ss = 0,
    .sp = 0x7c00,
-    .edx = edx
+    .edx = edx,
+    .a20 = 1
  };
  grub_video_set_mode ("text", 0, 0);

--- a/include/grub/i386/pc/loader.h
+++ b/include/grub/i386/pc/loader.h
@ -1,27 +0,0 @@
-/*
- *  GRUB  --  GRand Unified Bootloader
- *  Copyright (C) 2002,2003,2004,2007  Free Software Foundation, Inc.
- *
- *  GRUB is free software: you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation, either version 3 of the License, or
- *  (at your option) any later version.
- *
- *  GRUB is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-#ifndef GRUB_LOADER_MACHINE_HEADER
-#define GRUB_LOADER_MACHINE_HEADER	1
-
-#include <grub/symbol.h>
-
-/* This is an asm part of the chainloader.  */
-void EXPORT_FUNC(grub_chainloader_real_boot) (int drive, void *part_addr) __attribute__ ((noreturn));
-
-#endif /* ! GRUB_LOADER_MACHINE_HEADER */
--- a/include/grub/i386/relocator.h
+++ b/include/grub/i386/relocator.h
@ -48,6 +48,8 @@ struct grub_relocator16_state
  grub_uint16_t ip;
  grub_uint32_t ebx;
  grub_uint32_t edx;
+  grub_uint32_t esi;
+  int a20;
 };

 struct grub_relocator64_state