[PATCH 2/2 v2] x86: Add support for uncompressed kernel images

From: Christian Ruppert
Date: Mon Nov 18 2013 - 08:49:33 EST


There seems to be some interest to enable uncompressed kernels also for x86
in addition to (embedded) ARC platforms.

Add the code to support uncompressed kernels to lib/, select the respective
Kconfig options for the x86 architecture and use this code in the x86 kernel
self-decompressor.

Signed-off-by: Christian Ruppert <christian.ruppert@xxxxxxxxxx>
---
arch/x86/Kconfig | 1 +
arch/x86/boot/compressed/Makefile | 14 ++++++------
arch/x86/boot/compressed/misc.c | 4 +++
lib/decompress_copy.c | 44 +++++++++++++++++++++++++++++++++++++
4 files changed, 56 insertions(+), 7 deletions(-)
create mode 100644 lib/decompress_copy.c

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index e903c71..009349f 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -62,6 +62,7 @@ config X86
select USER_STACKTRACE_SUPPORT
select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_DMA_API_DEBUG
+ select HAVE_KERNEL_UNCOMPRESSED
select HAVE_KERNEL_GZIP
select HAVE_KERNEL_BZIP2
select HAVE_KERNEL_LZMA
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index dcd90df..f65e444 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -67,16 +67,16 @@ $(obj)/vmlinux.bin.lzo: $(vmlinux.bin.all-y) FORCE
$(obj)/vmlinux.bin.lz4: $(vmlinux.bin.all-y) FORCE
$(call if_changed,lz4)

-suffix-$(CONFIG_KERNEL_GZIP) := gz
-suffix-$(CONFIG_KERNEL_BZIP2) := bz2
-suffix-$(CONFIG_KERNEL_LZMA) := lzma
-suffix-$(CONFIG_KERNEL_XZ) := xz
-suffix-$(CONFIG_KERNEL_LZO) := lzo
-suffix-$(CONFIG_KERNEL_LZ4) := lz4
+suffix-$(CONFIG_KERNEL_GZIP) := .gz
+suffix-$(CONFIG_KERNEL_BZIP2) := .bz2
+suffix-$(CONFIG_KERNEL_LZMA) := .lzma
+suffix-$(CONFIG_KERNEL_XZ) := .xz
+suffix-$(CONFIG_KERNEL_LZO) := .lzo
+suffix-$(CONFIG_KERNEL_LZ4) := .lz4

quiet_cmd_mkpiggy = MKPIGGY $@
cmd_mkpiggy = $(obj)/mkpiggy $< > $@ || ( rm -f $@ ; false )

targets += piggy.S
-$(obj)/piggy.S: $(obj)/vmlinux.bin.$(suffix-y) $(obj)/mkpiggy FORCE
+$(obj)/piggy.S: $(obj)/vmlinux.bin$(suffix-y) $(obj)/mkpiggy FORCE
$(call if_changed,mkpiggy)
diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index 434f077..c210314 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -149,6 +149,10 @@ static int lines, cols;
#include "../../../../lib/decompress_unlz4.c"
#endif

+#ifdef CONFIG_KERNEL_UNCOMPRESSED
+#include "../../../../lib/decompress_copy.c"
+#endif
+
static void scroll(void)
{
int i;
diff --git a/lib/decompress_copy.c b/lib/decompress_copy.c
new file mode 100644
index 0000000..109ef22
--- /dev/null
+++ b/lib/decompress_copy.c
@@ -0,0 +1,44 @@
+#include <linux/decompress/mm.h>
+
+#define NOZIP_BUFSZ (16 * 1024)
+STATIC int INIT nozip(unsigned char *buf, int len,
+ int(*fill)(void*, unsigned int),
+ int(*flush)(void*, unsigned int),
+ unsigned char *outbuf,
+ int *pos,
+ void(*error)(char *x))
+{
+ char *b;
+
+ if (buf)
+ b = buf;
+ else
+ b = malloc(NOZIP_BUFSZ);
+
+ if (!b) {
+ error("Out of memory while allocating buffer");
+ return -1;
+ }
+
+ if (flush) {
+ if (!len)
+ len = fill(b, NOZIP_BUFSZ);
+
+ len = flush(b, len);
+ } else {
+ if (!len)
+ len = fill(outbuf, NOZIP_BUFSZ);
+ else
+ memcpy(outbuf, b, len);
+ }
+
+ if (pos)
+ *pos = len;
+
+ if (!buf)
+ free(b);
+
+ return 0;
+}
+
+#define decompress nozip
--
1.7.1

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