單板:GT2440
U-Boot源碼目錄:
從目錄下文件夾名稱應該可大概瞭解到每個文件夾下的代碼作用;
Step1:
U-Boot編譯: 1、配置
2、make
配置:make GTStudio_config
Make:make <’ ’|all >
關於u-boot的編譯與約定詳見:ROADME
ROADME是學習瞭解u-boot的相當詳細的資料。
Step2:
Makefile分析:
1、make GTStudio_config用意;
在u-boot目錄下打開makefile查找到GTStudio_config有如下語句:
GTStudio_config : unconfig
@$(MKCONFIG) $(@:_config=) arm arm920t GTStudio NULL s3c24x0
對上述腳本進行解析:
@$(MKCONFIG) = $(CURDIR)/mkconfig //既當前目錄下mkconfig
/* MKCONFIG := $(SRCTREE)/mkconfig */
/* SRCTREE := $(CURDIR) */
$(@:_config=) = $(@:_config= ‘ ’) = GTStudio
因此上面腳本可替換爲:
./mkconfig GTStudio arm arm920t GTStudio NULL s3c24x0
參數: $0 $1 $2 $3 $4 $5 $6
2、mkconfig分析
運行上解析的腳本代碼將吧$1~$6參數傳入至mkconfig中進行處理:
在mkconfig中對參數進行處理有如下代碼執行:
Asm-arm連接建立:
cd ./include
rm -f asm
ln -s asm-$2 asm
Asm-arm/arch連接建立:
ln -s ${LNPREFIX}arch-$6 asm-$2/arch
Asm-arm/proc連接建立:
rm -f asm-$2/proc
ln -s ${LNPREFIX}proc-armv asm-$2/proc
Config.mk創建:
echo "ARCH = $2" > config.mk
echo "CPU = $3" >> config.mk
echo "BOARD = $4" >> config.mk
[ "$5" ] && [ "$5" != "NULL" ] && echo "VENDOR = $5" >> config.mk
[ "$6" ] && [ "$6" != "NULL" ] && echo "SOC = $6" >> config.mk
Config.h創建:
> config.h # Create new config file
Config.h內容:
echo "/* Automatically generated - do not edit */" >>config.h
echo "#include <configs/$1.h>" >>config.h
3、make<’ ’|all>:
進入makefile查詢到make對應腳本代碼:
ALL = $(obj)u-boot.srec $(obj)u-boot.bin $(obj)System.map $(U_BOOT_NAND)
爲完成上述腳本操作則必須完成如下操作:
all: $(ALL)
$(obj)u-boot.hex: $(obj)u-boot
$(OBJCOPY) ${OBJCFLAGS} -O ihex $< $@
$(obj)u-boot.srec: $(obj)u-boot
$(OBJCOPY) ${OBJCFLAGS} -O srec $< $@
$(obj)u-boot.bin: $(obj)u-boot
$(OBJCOPY) ${OBJCFLAGS} -O binary $< $@
$(obj)u-boot.img: $(obj)u-boot.bin
./tools/mkimage -A $(ARCH) -T firmware -C none \
-a $(TEXT_BASE) -e 0 \
-n $(shell sed -n -e 's/.*U_BOOT_VERSION//p' $(VERSION_FILE) | \
sed -e 's/"[ ]*$$/ for $(BOARD) board"/') \
-d $< $@
$(obj)u-boot.dis: $(obj)u-boot
$(OBJDUMP) -d $< > $@
$(obj)u-boot: depend version $(SUBDIRS) $(OBJS) $(LIBS) $(LDSCRIPT)
UNDEF_SYM=`$(OBJDUMP) -x $(LIBS) |sed -n -e 's/.*\(__u_boot_cmd_.*\)/-u\1/p'|sort|uniq`;\
cd $(LNDIR) && $(LD) $(LDFLAGS) $$UNDEF_SYM $(__OBJS) \
--start-group $(__LIBS) --end-group $(PLATFORM_LIBS) \
-Map u-boot.map -o u-boot
$(OBJS):
echo $(OBJS)
$(MAKE) -C cpu/$(CPU) $(if $(REMOTE_BUILD),$@,$(notdir $@))
$(LIBS):
$(MAKE) -C $(dir $(subst $(obj),,$@))
lcd:
$(MAKE) -C drivers/lcd
$(SUBDIRS):
$(MAKE) -C $@ all
$(NAND_SPL): version
$(MAKE) -C nand_spl/board/$(BOARDDIR) all
$(U_BOOT_NAND): $(NAND_SPL) $(obj)u-boot.bin
cat $(obj)nand_spl/u-boot-spl-16k.bin $(obj)u-boot.bin > $(obj)u-boot-nand.bin
version:
@echo -n "#define U_BOOT_VERSION \"U-Boot " > $(VERSION_FILE); \
echo -n "$(U_BOOT_VERSION)" >> $(VERSION_FILE); \
echo -n $(shell $(CONFIG_SHELL) $(TOPDIR)/tools/setlocalversion \
$(TOPDIR)) >> $(VERSION_FILE); \
echo "\"" >> $(VERSION_FILE)
gdbtools:
$(MAKE) -C tools/gdb all || exit 1
updater:
$(MAKE) -C tools/updater all || exit 1
env:
$(MAKE) -C tools/env all || exit 1
depend dep:
for dir in $(SUBDIRS) ; do $(MAKE) -C $$dir _depend ; done
tags ctags:
ctags -w -o $(OBJTREE)/ctags `find $(SUBDIRS) include \
lib_generic board/$(BOARDDIR) cpu/$(CPU) lib_$(ARCH) \
fs/cramfs fs/jffs2 \
net rtc drivers wince common \
\( -name CVS -prune \) -o \( -name '*.[ch]' -print \)`
etags:
etags -a -o $(OBJTREE)/etags `find $(SUBDIRS) include \
lib_generic board/$(BOARDDIR) cpu/$(CPU) lib_$(ARCH) \
fs/cramfs fs/jffs2 \
net rtc drivers wince common \
\( -name CVS -prune \) -o \( -name '*.[ch]' -print \)`
$(obj)System.map: $(obj)u-boot
@$(NM) $< | \
grep -v '\(compiled\)\|\(\.o$$\)\|\( [aUw] \)\|\(\.\.ng$$\)\|\(LASH[RL]DI\)' | \
sort > $(obj)System.map
至此u-boot編譯完畢,且可下載。