From 303148045aac34b70db722a54e5ad94a3a6625c6 Mon Sep 17 00:00:00 2001
From: Lasse Collin <lasse.collin@tukaani.org>
Date: Wed, 12 Jan 2011 17:01:24 -0800
Subject: [PATCH] x86: support XZ-compressed kernel
This integrates the XZ decompression code to the x86 pre-boot code.
mkpiggy.c is updated to reserve about 32 KiB more buffer safety margin for
kernel decompression. It is done unconditionally for all decompressors to
keep the code simpler.
The XZ decompressor needs around 30 KiB of heap, so the heap size is
increased to 32 KiB on both x86-32 and x86-64.
Documentation/x86/boot.txt is updated to list the XZ magic number.
With the x86 BCJ filter in XZ, XZ-compressed x86 kernel tends to be a few
percent smaller than the equivalent LZMA-compressed kernel.
Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alain Knaff <alain@knaff.lu>
Cc: Albin Tonnerre <albin.tonnerre@free-electrons.com>
Cc: Phillip Lougher <phillip@lougher.demon.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
Documentation/x86/boot.txt | 6 +++---
arch/x86/Kconfig | 1 +
arch/x86/boot/compressed/Makefile | 5 ++++-
arch/x86/boot/compressed/misc.c | 4 ++++
arch/x86/boot/compressed/mkpiggy.c | 2 +-
arch/x86/include/asm/boot.h | 6 +-----
6 files changed, 14 insertions(+), 10 deletions(-)
diff --git a/Documentation/x86/boot.txt b/Documentation/x86/boot.txt
index bdeb81ccb5f61b..9b7221a86df291 100644
--- a/Documentation/x86/boot.txt
+++ b/Documentation/x86/boot.txt
@@ -622,9 +622,9 @@ Protocol: 2.08+
The payload may be compressed. The format of both the compressed and
uncompressed data should be determined using the standard magic
numbers. The currently supported compression formats are gzip
- (magic numbers 1F 8B or 1F 9E), bzip2 (magic number 42 5A) and LZMA
- (magic number 5D 00). The uncompressed payload is currently always ELF
- (magic number 7F 45 4C 46).
+ (magic numbers 1F 8B or 1F 9E), bzip2 (magic number 42 5A), LZMA
+ (magic number 5D 00), and XZ (magic number FD 37). The uncompressed
+ payload is currently always ELF (magic number 7F 45 4C 46).
Field name: payload_length
Type: read
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 8734db3c5830a9..6e15fa9455e0cc 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -51,6 +51,7 @@ config X86
select HAVE_KERNEL_GZIP
select HAVE_KERNEL_BZIP2
select HAVE_KERNEL_LZMA
+ select HAVE_KERNEL_XZ
select HAVE_KERNEL_LZO
select HAVE_HW_BREAKPOINT
select HAVE_MIXED_BREAKPOINTS_REGS
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index 0c229551eead15..09664efb9ceee4 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -4,7 +4,7 @@
# create a compressed vmlinux image from the original vmlinux
#
-targets := vmlinux.lds vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma vmlinux.bin.lzo head_$(BITS).o misc.o string.o cmdline.o early_serial_console.o piggy.o
+targets := vmlinux.lds vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma vmlinux.bin.xz vmlinux.bin.lzo head_$(BITS).o misc.o string.o cmdline.o early_serial_console.o piggy.o
KBUILD_CFLAGS := -m$(BITS) -D__KERNEL__ $(LINUX_INCLUDE) -O2
KBUILD_CFLAGS += -fno-strict-aliasing -fPIC
@@ -49,12 +49,15 @@ $(obj)/vmlinux.bin.bz2: $(vmlinux.bin.all-y) FORCE
$(call if_changed,bzip2)
$(obj)/vmlinux.bin.lzma: $(vmlinux.bin.all-y) FORCE
$(call if_changed,lzma)
+$(obj)/vmlinux.bin.xz: $(vmlinux.bin.all-y) FORCE
+ $(call if_changed,xzkern)
$(obj)/vmlinux.bin.lzo: $(vmlinux.bin.all-y) FORCE
$(call if_changed,lzo)
suffix-$(CONFIG_KERNEL_GZIP) := gz
suffix-$(CONFIG_KERNEL_BZIP2) := bz2
suffix-$(CONFIG_KERNEL_LZMA) := lzma
+suffix-$(CONFIG_KERNEL_XZ) := xz
suffix-$(CONFIG_KERNEL_LZO) := lzo
quiet_cmd_mkpiggy = MKPIGGY $@
diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index 325c05294fc40d..3a19d04cebebe9 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -139,6 +139,10 @@ static int lines, cols;
#include "../../../../lib/decompress_unlzma.c"
#endif
+#ifdef CONFIG_KERNEL_XZ
+#include "../../../../lib/decompress_unxz.c"
+#endif
+
#ifdef CONFIG_KERNEL_LZO
#include "../../../../lib/decompress_unlzo.c"
#endif
diff --git a/arch/x86/boot/compressed/mkpiggy.c b/arch/x86/boot/compressed/mkpiggy.c
index 5c228129d17577..646aa78ba5fdb2 100644
--- a/arch/x86/boot/compressed/mkpiggy.c
+++ b/arch/x86/boot/compressed/mkpiggy.c
@@ -74,7 +74,7 @@ int main(int argc, char *argv[])
offs = (olen > ilen) ? olen - ilen : 0;
offs += olen >> 12; /* Add 8 bytes for each 32K block */
- offs += 32*1024 + 18; /* Add 32K + 18 bytes slack */
+ offs += 64*1024 + 128; /* Add 64K + 128 bytes slack */
offs = (offs+4095) & ~4095; /* Round to a 4K boundary */
printf(".section \".rodata..compressed\",\"a\",@progbits\n");
diff --git a/arch/x86/include/asm/boot.h b/arch/x86/include/asm/boot.h
index 3b62ab56c7a04a..5e1a2eef3e7cad 100644
--- a/arch/x86/include/asm/boot.h
+++ b/arch/x86/include/asm/boot.h
@@ -32,11 +32,7 @@
#define BOOT_HEAP_SIZE 0x400000
#else /* !CONFIG_KERNEL_BZIP2 */
-#ifdef CONFIG_X86_64
-#define BOOT_HEAP_SIZE 0x7000
-#else
-#define BOOT_HEAP_SIZE 0x4000
-#endif
+#define BOOT_HEAP_SIZE 0x8000
#endif /* !CONFIG_KERNEL_BZIP2 */
--
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