ARM: 6026/1: ARM: Add support for LZMA-compressed kernel images

This patch allows using a kernel image compressed with LZMA on ARM.
Extracting the image is fairly slow, but it might be useful on machines
with a very limited amount of storage, as the size benefit is quite
significant (about 25% smaller with LZMA compared to GZIP)

Tested-by: Martin Michlmayr <tbm@cyrius.com>
Tested-by: Paulius Zaleckas <paulius.zaleckas@gmail.com>
Signed-off-by: Albin Tonnerre <albin.tonnerre@free-electrons.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

4 files changed, 12 insertions, 0 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index bf856f492eb5..5c8128c76996 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -21,6 +21,7 @@ config ARM
         select HAVE_GENERIC_DMA_COHERENT
         select HAVE_KERNEL_GZIP
         select HAVE_KERNEL_LZO
+        select HAVE_KERNEL_LZMA
         select HAVE_PERF_EVENTS
         select PERF_USE_VMALLOC
         help
diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile
index 97c89e7de7d3..53faa9063a03 100644
--- a/arch/arm/boot/compressed/Makefile
+++ b/arch/arm/boot/compressed/Makefile
@@ -65,6 +65,7 @@ SEDFLAGS	= s/TEXT_START/$(ZTEXTADDR)/;s/BSS_START/$(ZBSSADDR)/
 
 suffix_$(CONFIG_KERNEL_GZIP) = gzip
 suffix_$(CONFIG_KERNEL_LZO)  = lzo
+suffix_$(CONFIG_KERNEL_LZMA) = lzma
 
 targets       := vmlinux vmlinux.lds \
                  piggy.$(suffix_y) piggy.$(suffix_y).o \
diff --git a/arch/arm/boot/compressed/decompress.c b/arch/arm/boot/compressed/decompress.c
index 9c097073ce4c..4c72a97bc3e1 100644
--- a/arch/arm/boot/compressed/decompress.c
+++ b/arch/arm/boot/compressed/decompress.c
@@ -40,6 +40,10 @@ extern void error(char *);
 #include "../../../../lib/decompress_unlzo.c"
 #endif
 
+#ifdef CONFIG_KERNEL_LZMA
+#include "../../../../lib/decompress_unlzma.c"
+#endif
+
 void do_decompress(u8 *input, int len, u8 *output, void (*error)(char *x))
 {
         decompress(input, len, NULL, NULL, output, NULL, error);
diff --git a/arch/arm/boot/compressed/piggy.lzma.S b/arch/arm/boot/compressed/piggy.lzma.S
new file mode 100644
index 000000000000..d7e69cffbc0a
--- /dev/null
+++ b/arch/arm/boot/compressed/piggy.lzma.S
@@ -0,0 +1,6 @@
+        .section .piggydata,#alloc
+        .globl  input_data
+input_data:
+        .incbin "arch/arm/boot/compressed/piggy.lzma"
+        .globl  input_data_end
+input_data_end: