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authorLasse Collin <lasse.collin@tukaani.org>2011-01-12 17:01:24 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2011-01-13 08:03:25 -0800
commit303148045aac34b70db722a54e5ad94a3a6625c6 (patch)
tree9be64b5d44cbef232daf11a89107772cb21647de /arch/x86/boot
parent3ebe12439ba7fc62e1d6ecb569b7287771716ca1 (diff)
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>
Diffstat (limited to 'arch/x86/boot')
-rw-r--r--arch/x86/boot/compressed/Makefile5
-rw-r--r--arch/x86/boot/compressed/misc.c4
-rw-r--r--arch/x86/boot/compressed/mkpiggy.c2
3 files changed, 9 insertions, 2 deletions
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index 0c229551eea..09664efb9ce 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 325c05294fc..3a19d04cebe 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 5c228129d17..646aa78ba5f 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");