arm: Add support for LZ4-compressed kernel

Date	Tue, 26 Feb 2013 15:24:29 +0900

This patch integrates the LZ4 decompression code to the arm pre-boot code.
And it depends on two patchs below

lib: Add support for LZ4-compressed kernel
decompressor: Add LZ4 decompressor module

Signed-off-by: Kyungsik Lee <kyungsik.lee@lge.com>

v2:
- Apply CFLAGS, -Os to decompress.o to improve decompress
  performance during boot-up process

Signed-off-by: Paul Reioux <reioux@gmail.com>

Conflicts:
	arch/arm/boot/compressed/Makefile

arch/arm/Kconfig

@@ -19,6 +19,7 @@ config ARM
 	select HAVE_GENERIC_DMA_COHERENT
 	select HAVE_KERNEL_GZIP
 	select HAVE_KERNEL_LZO
+	select HAVE_KERNEL_LZ4
 	select HAVE_KERNEL_LZMA
 	select HAVE_IRQ_WORK
 	select HAVE_PERF_EVENTS

arch/arm/boot/compressed/Makefile

@@ -32,6 +32,10 @@ MISC = misc.o
 AFLAGS_decompress.o += -Wa,-march=armv7-a$(plus_sec)
 DECOMPRESS = decompress.o
 
+ifeq ($(CONFIG_KERNEL_LZ4),y)
+CFLAGS_decompress.o := -Os
+endif
+
 FONTC	= $(srctree)/drivers/video/console/font_acorn_8x8.c
 
 #
@@ -96,13 +100,14 @@ SEDFLAGS	= s/TEXT_START/$(ZTEXTADDR)/;s/BSS_START/$(ZBSSADDR)/
 suffix_$(CONFIG_KERNEL_GZIP) = gzip
 suffix_$(CONFIG_KERNEL_LZO)  = lzo
 suffix_$(CONFIG_KERNEL_LZMA) = lzma
+suffix_$(CONFIG_KERNEL_LZ4)  = lz4
 
 targets := vmlinux vmlinux.lds \
 		 piggy.$(suffix_y) piggy.$(suffix_y).o \
 		 font.o font.c head.o misc.o decompress.o $(OBJS)
 
 # Make sure files are removed during clean
-extra-y       += piggy.gzip piggy.lzo piggy.lzma lib1funcs.S
+extra-y       += piggy.gzip piggy.lzo piggy.lzma piggy.lz4 lib1funcs.S
 
 ifeq ($(CONFIG_FUNCTION_TRACER),y)
 ORIG_CFLAGS := $(KBUILD_CFLAGS)

arch/arm/boot/compressed/decompress.c

@@ -44,6 +44,10 @@ extern void error(char *);
 #include "../../../../lib/decompress_unlzma.c"
 #endif
 
+#ifdef CONFIG_KERNEL_LZ4
+#include "../../../../lib/decompress_unlz4.c"
+#endif
+
 int do_decompress(u8 *input, int len, u8 *output, void (*error)(char *x))
 {
 	return decompress(input, len, NULL, NULL, output, NULL, error);

arch/arm/boot/compressed/piggy.lz4.S

@@ -0,0 +1,6 @@
+	.section .piggydata,#alloc
+	.globl	input_data
+input_data:
+	.incbin	"arch/arm/boot/compressed/piggy.lz4"
+	.globl	input_data_end
+input_data_end: