[U-Boot] [PATCH v2] Add support for Linux-like kallsysms

19 May 2009

The kernel stores address<->symbol names in it so things can be decoded at
runtime.  Do it in U-Boot, and we get nice symbol decoding when crashing.
Some of this code was already in the Blackfin port, so generalize and split
it out for everyone to use.
Signed-off-by: Mike Frysinger vapier@gentoo.org
---
v2
    - complete patch made against the "next" branch
Makefile                          |   17 +++++++++++---
 common/Makefile                   |    1 +
 common/kallsyms.c                 |   44 +++++++++++++++++++++++++++++++++++++
 common/system_map.c               |    8 ++++++
 cpu/blackfin/system_map.S         |   18 ---------------
 cpu/blackfin/traps.c              |   35 ++++-------------------------
 include/common.h                  |    3 ++
 include/configs/bfin_adi_common.h |    2 +-
 8 files changed, 75 insertions(+), 53 deletions(-)
 create mode 100644 common/kallsyms.c
 create mode 100644 common/system_map.c
 delete mode 100644 cpu/blackfin/system_map.S

diff --git a/Makefile b/Makefile
index 81a5cd0..87f70ff 100644
--- a/Makefile
+++ b/Makefile
@@ -344,12 +344,19 @@ $(obj)u-boot.sha1:	$(obj)u-boot.bin
 $(obj)u-boot.dis:	$(obj)u-boot
    	$(OBJDUMP) -d $< > $@
-$(obj)u-boot:		depend $(SUBDIRS) $(OBJS) $(LIBBOARD) $(LIBS) $(LDSCRIPT)
+GEN_UBOOT = \
    	UNDEF_SYM=`$(OBJDUMP) -x $(LIBBOARD) $(LIBS) | \
    	sed  -n -e 's/.*($(SYM_PREFIX)__u_boot_cmd_.*)/-u\1/p'|sort|uniq`;\
    	cd $(LNDIR) && $(LD) $(LDFLAGS) $$UNDEF_SYM $(__OBJS) \
    		--start-group $(__LIBS) --end-group $(PLATFORM_LIBS) \
    		-Map u-boot.map -o u-boot
+$(obj)u-boot:		depend $(SUBDIRS) $(OBJS) $(LIBBOARD) $(LIBS) $(LDSCRIPT)
+		$(GEN_UBOOT)
+ifeq ($(CONFIG_KALLSYMS),y)
+		smap=`$(call SYSTEM_MAP,u-boot) | awk '$$2 ~ /[tTwW]/ {printf $$1 $$3 "\0"}'` ; \
+		$(CC) $(CFLAGS) -DSYSTEM_MAP=""$${smap}"" -c common/system_map.c -o $(obj)common/system_map.o
+		$(GEN_UBOOT) $(obj)common/system_map.o
+endif
$(OBJS):	depend
    	$(MAKE) -C cpu/$(CPU) $(if $(REMOTE_BUILD),$@,$(notdir $@))
@@ -448,10 +455,12 @@ cscope:
    					> cscope.files
    	cscope -b -q -k
-$(obj)System.map:	$(obj)u-boot
-		@$(NM) $< | \
+SYSTEM_MAP = \
+		$(NM) $1 | \
    	grep -v '(compiled)|(.o$$)|( [aUw] )|(..ng$$)|(LASH[RL]DI)' | \
-		sort > $(obj)System.map
+		LC_ALL=C sort
+$(obj)System.map:	$(obj)u-boot
+		@$(call SYSTEM_MAP,$<) > $(obj)System.map
#
 # Auto-generate the autoconf.mk file (which is included by all makefiles)
diff --git a/common/Makefile b/common/Makefile
index b9f4ca7..3c5ddc3 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -153,6 +153,7 @@ COBJS-$(CONFIG_CMD_DOC) += docecc.o
 COBJS-$(CONFIG_CONSOLE_MUX) += iomux.o
 COBJS-y += flash.o
 COBJS-$(CONFIG_CMD_KGDB) += kgdb.o
+COBJS-$(CONFIG_KALLSYMS) += kallsyms.o
 COBJS-$(CONFIG_LCD) += lcd.o
 COBJS-$(CONFIG_LYNXKDI) += lynxkdi.o
 COBJS-$(CONFIG_UPDATE_TFTP) += update.o
diff --git a/common/kallsyms.c b/common/kallsyms.c
new file mode 100644
index 0000000..ce42a93
--- /dev/null
+++ b/common/kallsyms.c
@@ -0,0 +1,44 @@
+/*
+ * Helper functions for working with the builtin symbol table
+ *
+ * Copyright (c) 2008-2009 Analog Devices Inc.
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <common.h>
+
+/* We need the weak marking as this symbol is provided specially */
+extern const char system_map[] __attribute__((weak));
+
+/* Given an address, return a pointer to the symbol name and store
+ * the base address in caddr.  So if the symbol map had an entry:
+ *		03fb9b7c_spi_cs_deactivate
+ * Then the following call:
+ *		unsigned long base;
+ *		const char *sym = symbol_lookup(0x03fb9b80, &base);
+ * Would end up setting the variables like so:
+ *		base = 0x03fb9b7c;
+ *		sym = "_spi_cs_deactivate";
+ */
+const char *symbol_lookup(unsigned long addr, unsigned long *caddr)
+{
+	const char *sym, *csym;
+	char *esym;
+	unsigned long sym_addr;
+
+	sym = system_map;
+	csym = NULL;
+	*caddr = 0;
+
+	while (*sym) {
+		sym_addr = simple_strtoul(sym, &esym, 16);
+		sym = esym;
+		if (sym_addr > addr)
+			break;
+		*caddr = sym_addr;
+		csym = sym;
+		sym += strlen(sym) + 1;
+	}
+
+	return csym;
+}
diff --git a/common/system_map.c b/common/system_map.c
new file mode 100644
index 0000000..8307293
--- /dev/null
+++ b/common/system_map.c
@@ -0,0 +1,8 @@
+/*
+ * The builtin symbol table for use with kallsyms
+ *
+ * Copyright (c) 2008-2009 Analog Devices Inc.
+ * Licensed under the GPL-2 or later.
+ */
+
+const char const system_map[] = SYSTEM_MAP;
diff --git a/cpu/blackfin/system_map.S b/cpu/blackfin/system_map.S
deleted file mode 100644
index 286d7f3..0000000
--- a/cpu/blackfin/system_map.S
+++ /dev/null
@@ -1,18 +0,0 @@
-/*
- * system_map.S - optional symbol lookup for debugging
- *
- * Copyright (c) 2007 Analog Devices Inc.
- * Licensed under the GPL-2 or later.
- */
-
-#include <config.h>
-
-#ifdef CONFIG_DEBUG_DUMP_SYMS
-.data
-.global _system_map
-.type _system_map,@object
-_system_map:
-#include SYM_FILE
-.asciz ""
-.size _system_map,.-_system_map
-#endif
diff --git a/cpu/blackfin/traps.c b/cpu/blackfin/traps.c
index 2121b0e..ad68346 100644
--- a/cpu/blackfin/traps.c
+++ b/cpu/blackfin/traps.c
@@ -171,38 +171,13 @@ void trap_c(struct pt_regs *regs)
 # define ENABLE_DUMP 0
 #endif
-#ifdef CONFIG_DEBUG_DUMP_SYMS
-# define ENABLE_DUMP_SYMS 1
-#else
-# define ENABLE_DUMP_SYMS 0
-#endif
-
-static const char *symbol_lookup(unsigned long addr, unsigned long *caddr)
+#ifndef CONFIG_KALLSYMS
+const char *symbol_lookup(unsigned long addr, unsigned long *caddr);
 {
-	if (!ENABLE_DUMP_SYMS)
-		return NULL;
-
-	extern const char system_map[] __attribute__((__weak__));
-	const char *sym, *csym;
-	char *esym;
-	unsigned long sym_addr;
-
-	sym = system_map;
-	csym = NULL;
-	*caddr = 0;
-
-	while (*sym) {
-		sym_addr = simple_strtoul(sym, &esym, 16);
-		sym = esym;
-		if (sym_addr > addr)
-			break;
-		*caddr = sym_addr;
-		csym = sym;
-		sym += strlen(sym) + 1;
-	}
-
-	return csym;
+	*caddr = addr;
+	return "N/A";
 }
+#endif
static void decode_address(char *buf, unsigned long address)
 {
diff --git a/include/common.h b/include/common.h
index 30fff7d..df0f5a0 100644
--- a/include/common.h
+++ b/include/common.h
@@ -300,6 +300,9 @@ int	misc_init_r   (void);
 /* common/exports.c */
 void	jumptable_init(void);
+/* common/kallsysm.c */
+const char *symbol_lookup(unsigned long addr, unsigned long *caddr);
+
 /* api/api.c */
 void	api_init (void);
diff --git a/include/configs/bfin_adi_common.h b/include/configs/bfin_adi_common.h
index bfe5376..e0be07b 100644
--- a/include/configs/bfin_adi_common.h
+++ b/include/configs/bfin_adi_common.h
@@ -91,7 +91,7 @@
  */
 #define CONFIG_ENV_OVERWRITE	1
 #define CONFIG_DEBUG_DUMP	1
-#define CONFIG_DEBUG_DUMP_SYMS	1
+#define CONFIG_KALLSYMS		1
 #define CONFIG_PANIC_HANG	1
/*
-- 
1.6.3.1


    