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authorH. Peter Anvin <hpa@zytor.com>2009-05-11 15:56:08 -0700
committerH. Peter Anvin <hpa@zytor.com>2009-05-11 17:44:39 -0700
commit37ba7ab5e33cebc25c68fffe33e9f21e7c2014e8 (patch)
tree006ba60fcd29b8fdee844ee6d90b85104a254d0d /arch/x86/boot
parent99aa45595f45603526513d5e29fc00f8afbf3913 (diff)
downloadlinux-37ba7ab5e33cebc25c68fffe33e9f21e7c2014e8.tar.gz
x86, boot: make kernel_alignment adjustable; new bzImage fields
Make the kernel_alignment field adjustable; this allows us to set it
to a large value (intended to be 16 MB to avoid ZONE_DMA contention,
memory holes and other weirdness) while a smart bootloader can still
force a loading at a lesser alignment if absolutely necessary.

Also export pref_address (preferred loading address, corresponding to
the link-time address) and init_size, the total amount of linear
memory the kernel will require during initialization.

[ Impact: allows better kernel placement, gives bootloader more info ]

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86/boot')
-rw-r--r--arch/x86/boot/compressed/head_32.S7
-rw-r--r--arch/x86/boot/compressed/head_64.S14
-rw-r--r--arch/x86/boot/header.S15
3 files changed, 28 insertions, 8 deletions
diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S
index 2b8e0dfa4b27..75e4f001e706 100644
--- a/arch/x86/boot/compressed/head_32.S
+++ b/arch/x86/boot/compressed/head_32.S
@@ -69,8 +69,11 @@ ENTRY(startup_32)
 
 #ifdef CONFIG_RELOCATABLE
 	movl	%ebp, %ebx
-	addl    $(CONFIG_PHYSICAL_ALIGN - 1), %ebx
-	andl    $(~(CONFIG_PHYSICAL_ALIGN - 1)), %ebx
+	movl	BP_kernel_alignment(%esi), %eax
+	decl	%eax
+	addl    %eax, %ebx
+	notl	%eax
+	andl    %eax, %ebx
 #else
 	movl	$LOAD_PHYSICAL_ADDR, %ebx
 #endif
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 2bb500af1bd7..f62c284db9eb 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -84,8 +84,11 @@ ENTRY(startup_32)
 
 #ifdef CONFIG_RELOCATABLE
 	movl	%ebp, %ebx
-	addl	$(PMD_PAGE_SIZE -1), %ebx
-	andl	$PMD_PAGE_MASK, %ebx
+	movl	BP_kernel_alignment(%esi), %eax
+	decl	%eax
+	addl	%eax, %ebx
+	notl	%eax
+	andl	%eax, %ebx
 #else
 	movl	$LOAD_PHYSICAL_ADDR, %ebx
 #endif
@@ -224,8 +227,11 @@ ENTRY(startup_64)
 	/* Start with the delta to where the kernel will run at. */
 #ifdef CONFIG_RELOCATABLE
 	leaq	startup_32(%rip) /* - $startup_32 */, %rbp
-	addq	$(PMD_PAGE_SIZE - 1), %rbp
-	andq	$PMD_PAGE_MASK, %rbp
+	movl	BP_kernel_alignment(%rsi), %eax
+	decl	%eax
+	addq	%rax, %rbp
+	notq	%rax
+	andq	%rax, %rbp
 #else
 	movq	$LOAD_PHYSICAL_ADDR, %rbp
 #endif
diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index 27285143adeb..a0b426978d55 100644
--- a/arch/x86/boot/header.S
+++ b/arch/x86/boot/header.S
@@ -116,7 +116,7 @@ _start:
 	# Part 2 of the header, from the old setup.S
 
 		.ascii	"HdrS"		# header signature
-		.word	0x0209		# header version number (>= 0x0105)
+		.word	0x020a		# header version number (>= 0x0105)
 					# or else old loadlin-1.5 will fail)
 		.globl realmode_swtch
 realmode_swtch:	.word	0, 0		# default_switch, SETUPSEG
@@ -201,7 +201,7 @@ relocatable_kernel:    .byte 1
 #else
 relocatable_kernel:    .byte 0
 #endif
-pad2:			.byte 0
+min_alignment:		.byte MIN_KERNEL_ALIGN_LG2	# minimum alignment
 pad3:			.word 0
 
 cmdline_size:   .long   COMMAND_LINE_SIZE-1     #length of the command line,
@@ -220,6 +220,17 @@ setup_data:		.quad 0			# 64-bit physical pointer to
 						# single linked list of
 						# struct setup_data
 
+pref_address:		.quad LOAD_PHYSICAL_ADDR	# preferred load addr
+
+#define ZO_INIT_SIZE	(ZO__end - ZO_startup_32 + ZO_extract_offset)
+#define VO_INIT_SIZE	(VO__end - VO__text)
+#if ZO_INIT_SIZE > VO_INIT_SIZE
+#define INIT_SIZE ZO_INIT_SIZE
+#else
+#define INIT_SIZE VO_INIT_SIZE
+#endif
+init_size:		.long INIT_SIZE		# kernel initialization size
+
 # End of setup header #####################################################
 
 	.section ".inittext", "ax"