[v4,2/2] ARM: uncompress debug support for multiplatform build

Commit Message

Shawn Guo March 11, 2013, 11:35 a.m. UTC

Instead of giving zero support of uncompress debug for multiplatform
build, the patch turns uncompress debug into one part of DEBUG_LL
support.  When DEBUG_LL is turned on for a particular platform,
uncompress debug works too for that platform.

OMAP is an exception here.  OMAP low-level debug code places data
in the .data section, and that is allowed in decompressor.  That's
why Kconfig symbol DEBUG_UNCOMPRESS that controls multiplatform
uncompress debug support is defined with !DEBUG_OMAP2PLUS_UART.

It creates arch/arm/boot/compressed/debug.S with CONFIG_DEBUG_LL_INCLUDE
included there, implements a generic putc() using those macros, which
will be built when DEBUG_UNCOMPRESS is defined.

Signed-off-by: Shawn Guo <[e-mail]>
Acked-by: Olof Johansson <[e-mail]>
---
 arch/arm/Kconfig.debug              |    4 ++++
 arch/arm/boot/compressed/Makefile   |    3 +++
 arch/arm/boot/compressed/debug.S    |   12 ++++++++++++
 arch/arm/include/debug/uncompress.h |    4 ++++
 4 files changed, 23 insertions(+)
 create mode 100644 arch/arm/boot/compressed/debug.S

Comments

Tony Lindgren March 11, 2013, 5:36 p.m. UTC | #1

* Shawn Guo <[e-mail]> [130311 04:39]:
> Instead of giving zero support of uncompress debug for multiplatform
> build, the patch turns uncompress debug into one part of DEBUG_LL
> support.  When DEBUG_LL is turned on for a particular platform,
> uncompress debug works too for that platform.
> 
> OMAP is an exception here.  OMAP low-level debug code places data
> in the .data section, and that is allowed in decompressor.  That's
> why Kconfig symbol DEBUG_UNCOMPRESS that controls multiplatform
> uncompress debug support is defined with !DEBUG_OMAP2PLUS_UART.

This seems like a good solution for now. Later on we can rip out
the use .data for omap and just rely on ifdefs for all the port
variables if we conclude that we won't try to attempt any runtime
autodetection for omaps. So for both patches:

Acked-by: Tony Lindgren <[e-mail]>

Patch

diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index fc54a5b..559228c 100644
--- a/arch/arm/Kconfig.debug
+++ b/arch/arm/Kconfig.debug
@@ -601,6 +601,10 @@  config DEBUG_LL_INCLUDE
 	default "debug/zynq.S" if DEBUG_ZYNQ_UART0 || DEBUG_ZYNQ_UART1
 	default "mach/debug-macro.S"
 
+config DEBUG_UNCOMPRESS
+	bool
+	default y if ARCH_MULTIPLATFORM && DEBUG_LL && !DEBUG_OMAP2PLUS_UART
+
 config UNCOMPRESS_INCLUDE
 	string
 	default "debug/uncompress.h" if ARCH_MULTIPLATFORM
diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile
index 5cad8a6..e3238bc 100644
--- a/arch/arm/boot/compressed/Makefile
+++ b/arch/arm/boot/compressed/Makefile
@@ -24,6 +24,9 @@  endif
 AFLAGS_head.o += -DTEXT_OFFSET=$(TEXT_OFFSET)
 HEAD	= head.o
 OBJS	+= misc.o decompress.o
+ifeq ($(CONFIG_DEBUG_UNCOMPRESS),y)
+OBJS	+= debug.o
+endif
 FONTC	= $(srctree)/drivers/video/console/font_acorn_8x8.c
 
 # string library code (-Os is enforced to keep it much smaller)
diff --git a/arch/arm/boot/compressed/debug.S b/arch/arm/boot/compressed/debug.S
new file mode 100644
index 0000000..6e8382d
--- /dev/null
+++ b/arch/arm/boot/compressed/debug.S
@@ -0,0 +1,12 @@ 
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+
+#include CONFIG_DEBUG_LL_INCLUDE
+
+ENTRY(putc)
+	addruart r1, r2, r3
+	waituart r3, r1
+	senduart r0, r1
+	busyuart r3, r1
+	mov	 pc, lr
+ENDPROC(putc)
diff --git a/arch/arm/include/debug/uncompress.h b/arch/arm/include/debug/uncompress.h
index e19955d..0e2949b 100644
--- a/arch/arm/include/debug/uncompress.h
+++ b/arch/arm/include/debug/uncompress.h
@@ -1,3 +1,7 @@ 
+#ifdef CONFIG_DEBUG_UNCOMPRESS
+extern void putc(int c);
+#else
 static inline void putc(int c) {}
+#endif
 static inline void flush(void) {}
 static inline void arch_decomp_setup(void) {}