Powerpc構(gòu)架系統(tǒng)內(nèi)核和內(nèi)核模塊調(diào)試
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說明：
本文引用地址：http://www.ex-cimer.com/article/148724.htm此文檔的目標(biāo)系統(tǒng)為freescale MPC8349E-mITX,對其他采用powerPC,MIPS，ARM的芯片的系統(tǒng)亦具有參考意義。 此文檔中內(nèi)核調(diào)試為了簡化，采用目標(biāo)系統(tǒng)中的UBOOT初始化目標(biāo)板，并通過UBOOT或者BDI2000加載內(nèi)核到目標(biāo)板的RAM中。
1. BDI2000配置：
下面是MPC8349E-mITX的BDI2000配置文件，
; BDI-2000 CONfiguraTIon file for the MPC8349E-mITX
; Tip: If after a reset, the BDI-2000 fails to halt at 0x100,
; you may need to power-down the bOArd for a few seconds.
[INIT]
; we use UBOOT to initialize the board
[TARGET]
CPUTYPE 8349
JTAGCLOCK 1
;STARTUP RESET
STARTUP RUN
BREAKMODE HARD
STEPMODE HWBP
BOOTADDR 0x00000100
;If you're getting Writing to workspace failed errors during flash operations,
;then try uncommenting this line instead. This moves the FLASH window to
;high memory, leaving low memory available for DDR.
RCW 0xb060a000 0x04040000 ;Set the HRCW to boot the image at 0xFE000000
MMU XLAT ;0xc0000000
PTBASE 0xf0 ;
[HOST]
IP 192.168.7.90
FILE $u-boot.bin
LOAD MANUAL
PROMPT 8349E-mITX-GP>
DUMP itx-dump.bin
[Flash]
CHIPTYPE AM29BX16
CHIPSIZE 0x800000
BUSWIDTH 16
;WORKSPACE 0x1000
FORMAT BIN 0xfe000000
;flash_image.bin is an image file of an entire 8MB flash region.
;Flash this file at 0xfe0000000 to restore all of flash.
;ERASE 0xFE000000 0x10000 127 ; 127 sectors @ 64KB each
;ERASE 0xFE7F0000 0x2000 8 ; 8 sectors @ 8KB each
;FILE $flash_image.bin
;Use these lines if you just want to flash U-Boot
ERASE 0xfe000000 0x10000? 4; Erase 384KB, each sector is 64KB
FILE? mpc8349e/u-boot131-mitx-gp.bin
[REGS]
FILE $reg8349e.def
以上配置文件的【HOST】段的IP要改為主機(jī)IP，關(guān)鍵的字段MMU XLAT 和PTBASE 是POWERPC和MIPS經(jīng)常需要設(shè)置的，關(guān)于PTBASE的具體設(shè)置，超出本文范圍，詳細(xì)情況請參考BDI2000的手冊
2.內(nèi)核修改和配置
為了能夠調(diào)試內(nèi)核，需要在內(nèi)核中的Makefile中增加如下調(diào)試選項(xiàng)：
CFLAGS 增加C代碼調(diào)試選項(xiàng)-g –ggdb
AFLAGS 增加匯編代碼調(diào)試選項(xiàng)：-Wa,-L -gdwarf-2
去掉CFLAGS編譯選項(xiàng)中-fomit-frAME-pointer
GCC的-fomit-frame-pointer選項(xiàng)是優(yōu)化函數(shù)?；厮?stack backtrace)的，我們調(diào)試的時(shí)候需要提供函數(shù)回溯能力，所以我們要去掉這個(gè)選項(xiàng)，當(dāng)然，有的系統(tǒng)系統(tǒng)不受它的影響，或者說它不起作用，為了統(tǒng)一，我們統(tǒng)一去掉它。
相對個(gè)案來說，我是做如下改動(dòng)的：
--- Makefile 2008-07-08 03:07:38.000000000 +0800
+++ Makefile.debug 2008-07-08 03:06:04.000000000 +0800
…
-CPPFLAGS := -D__KERNEL__ $(LINUXINCLUDE)
+ifdef CONFIG_DEBUG_INFO
+
+ CPPFLAGS := -D__KERNEL__ $(LINUXINCLUDE) -g -ggdb
-CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs
+ CFLAGS := $(CPPFLAGS) -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs
-fno-strict-aliasing -fno-common
-AFLAGS := -D__ASSEMBLY__
+ AFLAGS := -D__ASSEMBLY__ -Wa,-L -gdwarf-2
+else
+ CPPFLAGS := -D__KERNEL__ $(LINUXINCLUDE)
+ CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs
+ -fno-strict-aliasing -fno-common
+ AFLAGS := -D__ASSEMBLY__
+
+endif
…
@@ -491,27 +500,33 @@
# Defaults vmlinux but it is usually overridden in the arch makefile
all: vmlinux
-ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
-CFLAGS += -Os
-else
-CFLAGS += -O2
-endif
include $(srctree)/arch/$(ARCH)/Makefile
-ifdef CONFIG_FRAME_POINTER
-CFLAGS += -fno-omit-frame-pointer $(call cc-option,-fno-optimize-sibling-calls,)
-else
-CFLAGS += -fomit-frame-pointer
-endif
ifdef CONFIG_UNWIND_INFO
CFLAGS += -fasynchronous-unwind-tables
endif
-ifdef CONFIG_DEBUG_INFO
-CFLAGS += -g
-endif
+#ifdef CONFIG_DEBUG_INFO
+CFLAGS += -fno-omit-frame-pointer $(call cc-option,-fno-optimize-sibling-calls,)
+CFLAGS += -g -ggdb
+CFLAGS += -O
+#else
+
+# ifdef CONFIG_FRAME_POINTER
+ CFLAGS += -fno-omit-frame-pointer $(call cc-option,-fno-optimize-sibling-calls,)
+# else
+ CFLAGS += -fomit-frame-pointer
+# endif
+
+# ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
+ CFLAGS += -Os
+# else
+ CFLAGS += -O2
+# endif
+
+#endif
通過以上修改后，系統(tǒng)的的調(diào)試信息簡單的通過CONFIG_DEBUG_INFO宏來控制了，那么CONFIG_DEBUG_INFO宏又是從哪里來的呢?它其實(shí)是從內(nèi)核的配置文件.config里面來的。
一般內(nèi)核通過make menuconfig做配置的時(shí)候，都有
Kernel hacking --->
[*] Kernel debugging
[*] Compile the kernel with debug info
[*] Force gcc to inline functions marked 'inline' (2.6比較新的內(nèi)核有這一項(xiàng))
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