X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=arch%2Fx86%2Fboot%2Fheader.S;h=af86e431acfae2af91957a9932c3bf5fb96bd5fb;hb=bd5d435a96837c3495e62eef37cbe4cb728b79ae;hp=6ef5a060fa11085df5be8d4616acd5541b53d5d2;hpb=3830de73000c07b2cbdf8cc31a46a01dda28c5df;p=linux-2.6-omap-h63xx.git

diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index 6ef5a060fa1..af86e431acf 100644
--- a/arch/x86/boot/header.S
+++ b/arch/x86/boot/header.S
@@ -22,6 +22,7 @@
 #include <asm/page.h>
 #include <asm/setup.h>
 #include "boot.h"
+#include "offsets.h"
 
 SETUPSECTS	= 4			/* default nr of setup-sectors */
 BOOTSEG		= 0x07C0		/* original address of boot-sector */
@@ -119,7 +120,7 @@ _start:
 	# Part 2 of the header, from the old setup.S
 
 		.ascii	"HdrS"		# header signature
-		.word	0x0207		# header version number (>= 0x0105)
+		.word	0x0209		# header version number (>= 0x0105)
 					# or else old loadlin-1.5 will fail)
 		.globl realmode_swtch
 realmode_swtch:	.word	0, 0		# default_switch, SETUPSEG
@@ -195,10 +196,13 @@ cmd_line_ptr:	.long	0		# (Header version 0x0202 or later)
 					# can be located anywhere in
 					# low memory 0x10000 or higher.
 
-ramdisk_max:	.long (-__PAGE_OFFSET-(512 << 20)-1) & 0x7fffffff
+ramdisk_max:	.long 0x7fffffff
 					# (Header version 0x0203 or later)
 					# The highest safe address for
 					# the contents of an initrd
+					# The current kernel allows up to 4 GB,
+					# but leave it at 2 GB to avoid
+					# possible bootloader bugs.
 
 kernel_alignment:  .long CONFIG_PHYSICAL_ALIGN	#physical addr alignment
 						#required for protected mode
@@ -220,6 +224,13 @@ hardware_subarch:	.long 0			# subarchitecture, added with 2.07
 
 hardware_subarch_data:	.quad 0
 
+payload_offset:		.long input_data
+payload_length:		.long input_data_end-input_data
+
+setup_data:		.quad 0			# 64-bit physical pointer to
+						# single linked list of
+						# struct setup_data
+
 # End of setup header #####################################################
 
 	.section ".inittext", "ax"
@@ -236,39 +247,30 @@ start_of_setup:
 	movw	%ax, %es
 	cld
 
-# Apparently some ancient versions of LILO invoked the kernel
-# with %ss != %ds, which happened to work by accident for the
-# old code.  If the CAN_USE_HEAP flag is set in loadflags, or
-# %ss != %ds, then adjust the stack pointer.
+# Apparently some ancient versions of LILO invoked the kernel with %ss != %ds,
+# which happened to work by accident for the old code.  Recalculate the stack
+# pointer if %ss is invalid.  Otherwise leave it alone, LOADLIN sets up the
+# stack behind its own code, so we can't blindly put it directly past the heap.
 
-	# Smallest possible stack we can tolerate
-	movw	$(_end+STACK_SIZE), %cx
-
-	movw	heap_end_ptr, %dx
-	addw	$512, %dx
-	jnc	1f
-	xorw	%dx, %dx	# Wraparound - whole segment available
-1:	testb	$CAN_USE_HEAP, loadflags
-	jnz	2f
-
-	# No CAN_USE_HEAP
 	movw	%ss, %dx
 	cmpw	%ax, %dx	# %ds == %ss?
 	movw	%sp, %dx
-	# If so, assume %sp is reasonably set, otherwise use
-	# the smallest possible stack.
-	jne	4f		# -> Smallest possible stack...
+	je	2f		# -> assume %sp is reasonably set
+
+	# Invalid %ss, make up a new stack
+	movw	$_end, %dx
+	testb	$CAN_USE_HEAP, loadflags
+	jz	1f
+	movw	heap_end_ptr, %dx
+1:	addw	$STACK_SIZE, %dx
+	jnc	2f
+	xorw	%dx, %dx	# Prevent wraparound
 
-	# Make sure the stack is at least minimum size.  Take a value
-	# of zero to mean "full segment."
-2:
+2:	# Now %dx should point to the end of our stack space
 	andw	$~3, %dx	# dword align (might as well...)
 	jnz	3f
 	movw	$0xfffc, %dx	# Make sure we're not zero
-3:	cmpw	%cx, %dx
-	jnb	5f
-4:	movw	%cx, %dx	# Minimum value we can possibly use
-5:	movw	%ax, %ss
+3:	movw	%ax, %ss
 	movzwl	%dx, %esp	# Clear upper half of %esp
 	sti			# Now we should have a working stack