[PATCH] Revert "init/Kconfig: add option to disable kernel compression"

[PATCH] Revert "init/Kconfig: add option to disable kernel compression"

[H. Peter Anvin]

From: "H. Peter Anvin" <hpa@zytor.com>

This reverts commit 69f0554ec261fd686ac7fa1c598cc9eb27b83a80.

This patch breaks randconfig on at least the x86-64 architecture, and
most likely on others.  There is work underway to support uncompressed
kernels in a generic way, but it looks like it will amount to
rewriting the support from scratch; see the LKML thread in the Link:
for info.

Therefore, revert this change and wait for the fix.

Reported-by: Pavel Roskin <proski@gnu.org>
Cc: Christian Ruppert <christian.ruppert@abilis.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20131113113418.167b8ffd@IRBT4585
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
---
 init/Kconfig | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/init/Kconfig b/init/Kconfig
index 5496f307988e..bc8911fab28e 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -118,6 +118,7 @@ config HAVE_KERNEL_LZ4
 choice
 	prompt "Kernel compression mode"
 	default KERNEL_GZIP
+	depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO || HAVE_KERNEL_LZ4
 	help
 	  The linux kernel is a kind of self-extracting executable.
 	  Several compression algorithms are available, which differ
@@ -136,13 +137,6 @@ choice
 
 	  If in doubt, select 'gzip'
 
-config KERNEL_UNCOMPRESSED
-	bool "No compression"
-	help
-	  No compression at all. The kernel is huge but the compression and
-	  decompression times are zero.
-	  This is usually not what you want.
-
 config KERNEL_GZIP
 	bool "Gzip"
 	depends on HAVE_KERNEL_GZIP
-- 
1.8.3.1

[PATCH] [FIX] init/Kconfig: fix option to disable kernel compression

[Christian Ruppert]

Some architectures with self-decompressing kernel images did not compile
with commit 69f0554ec261fd686ac7fa1c598cc9eb27b83a80 because they don't
provide a non-decompression mechanism for uncompressed kernels.

Rectify this problem by allowing uncompressed kernels only for architectures
which explicitly state they support them.

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
---
 arch/arc/Kconfig | 2 ++
 init/Kconfig     | 5 +++++
 2 files changed, 7 insertions(+)

diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 2ee0c9b..15f4c3d 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -21,6 +21,8 @@ config ARC
 	select HAVE_ARCH_KGDB
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_IOREMAP_PROT
+	select HAVE_KERNEL_UNCOMPRESSED
+	select HAVE_KERNEL_GZIP
 	select HAVE_KPROBES
 	select HAVE_KRETPROBES
 	select HAVE_MEMBLOCK
diff --git a/init/Kconfig b/init/Kconfig
index 5496f30..d4baf2e 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -97,6 +97,9 @@ config LOCALVERSION_AUTO
 
 	  which is done within the script "scripts/setlocalversion".)
 
+config HAVE_KERNEL_UNCOMPRESSED
+        bool
+
 config HAVE_KERNEL_GZIP
 	bool
 
@@ -118,6 +121,7 @@ config HAVE_KERNEL_LZ4
 choice
 	prompt "Kernel compression mode"
 	default KERNEL_GZIP
+	depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO || HAVE_KERNEL_LZ4 || HAVE_KERNEL_UNCOMPRESSED
 	help
 	  The linux kernel is a kind of self-extracting executable.
 	  Several compression algorithms are available, which differ
@@ -138,6 +142,7 @@ choice
 
 config KERNEL_UNCOMPRESSED
 	bool "No compression"
+	depends on HAVE_KERNEL_UNCOMPRESSED
 	help
 	  No compression at all. The kernel is huge but the compression and
 	  decompression times are zero.
-- 
1.8.4

Re: [PATCH] [FIX] init/Kconfig: fix option to disable kernel compression

[Vineet Gupta]

On 11/15/2013 10:21 PM, Christian Ruppert wrote:
> Some architectures with self-decompressing kernel images did not compile
> with commit 69f0554ec261fd686ac7fa1c598cc9eb27b83a80 because they don't
> provide a non-decompression mechanism for uncompressed kernels.
> 
> Rectify this problem by allowing uncompressed kernels only for architectures
> which explicitly state they support them.
> 
> Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>


Acked-by: Vineet Gupta <vgupta@synopsys.com>

> ---
>  arch/arc/Kconfig | 2 ++
>  init/Kconfig     | 5 +++++
>  2 files changed, 7 insertions(+)
> 
> diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
> index 2ee0c9b..15f4c3d 100644
> --- a/arch/arc/Kconfig
> +++ b/arch/arc/Kconfig
> @@ -21,6 +21,8 @@ config ARC
>  	select HAVE_ARCH_KGDB
>  	select HAVE_ARCH_TRACEHOOK
>  	select HAVE_IOREMAP_PROT
> +	select HAVE_KERNEL_UNCOMPRESSED
> +	select HAVE_KERNEL_GZIP
>  	select HAVE_KPROBES
>  	select HAVE_KRETPROBES
>  	select HAVE_MEMBLOCK
> diff --git a/init/Kconfig b/init/Kconfig
> index 5496f30..d4baf2e 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -97,6 +97,9 @@ config LOCALVERSION_AUTO
>  
>  	  which is done within the script "scripts/setlocalversion".)
>  
> +config HAVE_KERNEL_UNCOMPRESSED
> +        bool
> +
>  config HAVE_KERNEL_GZIP
>  	bool
>  
> @@ -118,6 +121,7 @@ config HAVE_KERNEL_LZ4
>  choice
>  	prompt "Kernel compression mode"
>  	default KERNEL_GZIP
> +	depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO || HAVE_KERNEL_LZ4 || HAVE_KERNEL_UNCOMPRESSED
>  	help
>  	  The linux kernel is a kind of self-extracting executable.
>  	  Several compression algorithms are available, which differ
> @@ -138,6 +142,7 @@ choice
>  
>  config KERNEL_UNCOMPRESSED
>  	bool "No compression"
> +	depends on HAVE_KERNEL_UNCOMPRESSED
>  	help
>  	  No compression at all. The kernel is huge but the compression and
>  	  decompression times are zero.
> 

Re: [PATCH] [FIX] init/Kconfig: fix option to disable kernel compression

[Christian Ruppert]

On Sat, Nov 16, 2013 at 03:12:56PM +0530, Vineet Gupta wrote:
> On 11/15/2013 10:21 PM, Christian Ruppert wrote:
> > Some architectures with self-decompressing kernel images did not compile
> > with commit 69f0554ec261fd686ac7fa1c598cc9eb27b83a80 because they don't
> > provide a non-decompression mechanism for uncompressed kernels.
> > 
> > Rectify this problem by allowing uncompressed kernels only for architectures
> > which explicitly state they support them.
> > 
> > Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
> Acked-by: Vineet Gupta <vgupta@synopsys.com>

Looks like the revert was applied to main line (and not this fix). In
the follow-up the complete (fixed) patch set rebased on the latest main
line: First patch for Kconfig/ARC and as requested a cleaned up second
patch for x86. I could only test the second patch on one physical
machine and one VM so some more testing might be required on x86.

Greetings,
  Christian

[PATCH 1/2] init/Kconfig: add option to disable kernel compression

[Christian Ruppert]

Some ARC users say they can boot faster with without kernel compression.
This probably depends on things like the FLASH chip they use etc.

Until now, kernel compression can only be disabled by removing "select
HAVE_<compression>" lines from the architecture Kconfig.  So add the
Kconfig logic to permit disabling of kernel compression.

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
---
 arch/arc/Kconfig |    2 ++
 init/Kconfig     |   13 ++++++++++++-
 2 files changed, 14 insertions(+), 1 deletions(-)

diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 2ee0c9b..15f4c3d 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -21,6 +21,8 @@ config ARC
 	select HAVE_ARCH_KGDB
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_IOREMAP_PROT
+	select HAVE_KERNEL_UNCOMPRESSED
+	select HAVE_KERNEL_GZIP
 	select HAVE_KPROBES
 	select HAVE_KRETPROBES
 	select HAVE_MEMBLOCK
diff --git a/init/Kconfig b/init/Kconfig
index 3fc8a2f..a21e94b 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -97,6 +97,9 @@ config LOCALVERSION_AUTO
 
 	  which is done within the script "scripts/setlocalversion".)
 
+config HAVE_KERNEL_UNCOMPRESSED
+        bool
+
 config HAVE_KERNEL_GZIP
 	bool
 
@@ -118,7 +121,7 @@ config HAVE_KERNEL_LZ4
 choice
 	prompt "Kernel compression mode"
 	default KERNEL_GZIP
-	depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO || HAVE_KERNEL_LZ4
+	depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO || HAVE_KERNEL_LZ4 || HAVE_KERNEL_UNCOMPRESSED
 	help
 	  The linux kernel is a kind of self-extracting executable.
 	  Several compression algorithms are available, which differ
@@ -137,6 +140,14 @@ choice
 
 	  If in doubt, select 'gzip'
 
+config KERNEL_UNCOMPRESSED
+	bool "No compression"
+	depends on HAVE_KERNEL_UNCOMPRESSED
+	help
+	  No compression at all. The kernel is huge but the compression and
+	  decompression times are zero.
+	  This is usually not what you want.
+
 config KERNEL_GZIP
 	bool "Gzip"
 	depends on HAVE_KERNEL_GZIP
-- 
1.7.1

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

[Christian Ruppert]

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
---
 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

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

[Borislav Petkov]

On Mon, Nov 18, 2013 at 10:51:51AM +0100, Christian Ruppert wrote:

How about a commit message ... somewhere around here would be nice, for
example :)

> Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
> ---
>  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

-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
--

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

[Christian Ruppert]

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@abilis.com>
---
 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

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

[Christian Ruppert]

On Mon, Nov 18, 2013 at 02:48:30PM +0100, Christian Ruppert wrote:
> 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.

Any news on this? Was someone able to take a look at / test this patch?
I have given it some more testing and encountered no issues so far.

Greetings,
  Christian

Re: Uncompressed kernel doesn't build on x86_64

[Christian Ruppert]

On Wed, Nov 13, 2013 at 11:34:18AM -0500, Pavel Roskin wrote:
> Hi Christian,
> 
> Your recent patch enables uncompressed kernels, but selecting that
> option (CONFIG_KERNEL_UNCOMPRESSED) fails on x86_86:
> [...]
> arch/x86/boot/compressed/Makefile has no provision for uncompressed
> files.  There is no definition for suffix-$(CONFIG_KERNEL_UNCOMPRESSED)
> so $(suffix-y) evaluates to an empty string and there is no rule to
> make vmlinuz.bin.$(suffix-y)
> 
> I think the patch should be either reverted or fixed as soon as
> possible.

This is an interesting observation, thanks. Although this patch is
rather intended for embedded architectures than x86, it highlights
potential issues with self-decompressing images of all sorts. I have no
way of testing all architectures and so I'm sending two patches in the
follow-up:
1. A conservative version of the original patch which requires
   architectures to explicitly enable uncompresed kernel images if they
   support compression as well and falls back to previous behaviour if
   nothing is specified. I have copied Vineet Gupta (maintainer of the
   ARC platform) since I enabled GZIP and uncompressed kernels for ARC
   by default.
2. A patch to enable uncompressed x86 kernels. As stated above, I don't
   think this makes a lot of sense in itself but it might serve as an
   example for people working on other platforms with self-extracting
   kernels and the nozip not-decompression algorithm might be useful on
   those platforms as well. I only had a single x86-64 machine available
   to test this, however, so some more testing might be required.

> Any suggestions for uncompressed suffix?  I'd go with "copy".  Then the
> "compression" could be a symlink.  Alternatively, the "." could be
> included in other suffixes, the uncompressed suffix would be empty and
> the compression would be an empty statement.

I followed H. Peter's suggestion and chose option 2 in patch 2.

Greetings,
  Christian

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

[Christian Ruppert]

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
---
 arch/x86/Kconfig                  |  1 +
 arch/x86/boot/compressed/Makefile | 14 ++++++------
 arch/x86/boot/compressed/misc.c   |  4 ++++
 lib/decompress_copy.c             | 47 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 59 insertions(+), 7 deletions(-)
 create mode 100644 lib/decompress_copy.c

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index f67e839..2a32df9 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -61,6 +61,7 @@ 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..8a41090
--- /dev/null
+++ b/lib/decompress_copy.c
@@ -0,0 +1,47 @@
+#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 {
+			int i;
+			for (i = 0; i < len; i++)
+				outbuf[i] = b[i];
+		}
+	}
+
+	if (pos)
+		*pos = len;
+
+	if (!buf)
+		free(b);
+
+	return 0;
+}
+
+#define decompress nozip
-- 
1.8.4

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

[H. Peter Anvin]

So it sounds like we're starting from the beginning - I presume that
means the patch currently in the kernel should be reverted first?

	-hpa

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

[Christian Ruppert]

On Thu, Nov 14, 2013 at 09:31:44AM -0800, H. Peter Anvin wrote:
> So it sounds like we're starting from the beginning - I presume that
> means the patch currently in the kernel should be reverted first?

Ack

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

[H. Peter Anvin]

On 11/14/2013 12:38 AM, Christian Ruppert wrote:
> diff --git a/lib/decompress_copy.c b/lib/decompress_copy.c
> new file mode 100644
> index 0000000..8a41090
> --- /dev/null
> +++ b/lib/decompress_copy.c
> @@ -0,0 +1,47 @@
> +#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 {
> +			int i;
> +			for (i = 0; i < len; i++)
> +				outbuf[i] = b[i];

Clever way of doing memcpy().  I know some other compression
implementations open-code memmove(), but using it for the entire data
set in the most common case is atrocious.  If we need to get a default
implementation of memmove() we should just do that.

	-hpa

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

[Christian Ruppert]

On Thu, Nov 14, 2013 at 09:45:12AM -0800, H. Peter Anvin wrote:
> On 11/14/2013 12:38 AM, Christian Ruppert wrote:
> > diff --git a/lib/decompress_copy.c b/lib/decompress_copy.c
> > new file mode 100644
> > index 0000000..8a41090
> > --- /dev/null
> > +++ b/lib/decompress_copy.c
> > @@ -0,0 +1,47 @@
> > +#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 {
> > +			int i;
> > +			for (i = 0; i < len; i++)
> > +				outbuf[i] = b[i];
> 
> Clever way of doing memcpy().  I know some other compression
> implementations open-code memmove(), but using it for the entire data
> set in the most common case is atrocious.  If we need to get a default
> implementation of memmove() we should just do that.

Actually, the x86 architecture already contains a basic implementation
of memcpy in its self-decompressor. Correct me if I'm wrong but I guess
memmove is not required since I don't expect the output of a generic
decompression function to overlap with its input.

We can simply use that function if we agree that
. either nozip is x86 specific
. or every architecture using this code must bring along its own memcpy
  implementation in its self-decompressor.

Do you think that would be OK?

Greetings,
  Christian

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

[H. Peter Anvin]

On 11/15/2013 01:49 AM, Christian Ruppert wrote:
> 
> Actually, the x86 architecture already contains a basic implementation
> of memcpy in its self-decompressor. Correct me if I'm wrong but I guess
> memmove is not required since I don't expect the output of a generic
> decompression function to overlap with its input.
> 
> We can simply use that function if we agree that
> . either nozip is x86 specific
> . or every architecture using this code must bring along its own memcpy
>   implementation in its self-decompressor.
> 
> Do you think that would be OK?
> 

I think all of them have memcpy().

	-hpa