最新有點時間，所以想折騰點東西，於是拿起了幾年前的TQ2440玩玩，下載了uboot2014.10版本，准備移植到板子上去，沒想到折騰環境都折騰了一下午。
1.工具鏈安裝
我的工具鏈直接用命令安裝的：
sudo apt-get install arm-linux-gnueabi
安裝完之后測試下：
k@localhost ~/w/0/uboot2014.10> arm-linux-gnueabi-gcc -v Using built-in specs. COLLECT_GCC=arm-linux-gnueabi-gcc COLLECT_LTO_WRAPPER=/usr/lib/gcc-cross/arm-linux-gnueabi/5/lto-wrapper Target: arm-linux-gnueabi Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 5.4.0-6ubuntu1~16.04.4' --with-bugurl=file:///usr/share/doc/gcc-5/README.Bugs --enable-languages=c,ada,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-5 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-libitm --disable-libquadmath --enable-plugin --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-5-armel-cross/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-5-armel-cross --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-5-armel-cross --with-arch-directory=arm --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --disable-libgcj --enable-objc-gc --enable-multiarch --enable-multilib --disable-sjlj-exceptions --with-arch=armv5t --with-float=soft --disable-werror --enable-multilib --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=arm-linux-gnueabi --program-prefix=arm-linux-gnueabi- --includedir=/usr/arm-linux-gnueabi/include Thread model: posix gcc version 5.4.0 20160609 (Ubuntu/Linaro 5.4.0-6ubuntu1~16.04.4)
2.修改頂層makefile：
ifeq ($(HOSTARCH),$(ARCH)) CROSS_COMPILE ?= endif 修改成： ifeq ($(HOSTARCH),$(ARCH)) CROSS_COMPILE ?= arm-linux-gnueabi- endif
默認的configs文件在comfgs/目錄下，於是直接運行以下命令：
k@localhost ~/w/0/uboot2014.10> make smdk2410_defconfig HOSTCC scripts/basic/fixdep HOSTCC scripts/kconfig/conf.o SHIPPED scripts/kconfig/zconf.tab.c SHIPPED scripts/kconfig/zconf.lex.c SHIPPED scripts/kconfig/zconf.hash.c HOSTCC scripts/kconfig/zconf.tab.o In file included from scripts/kconfig/zconf.tab.c:2537:0: scripts/kconfig/menu.c: In function ‘get_symbol_str’: scripts/kconfig/menu.c:590:18: warning: ‘jump’ may be used uninitialized in this function [-Wmaybe-uninitialized] jump->offset = strlen(r->s); ^ scripts/kconfig/menu.c:551:19: note: ‘jump’ was declared here struct jump_key *jump; ^ HOSTLD scripts/kconfig/conf # # configuration written to .config # k@localhost ~/w/0/uboot2014.10> make scripts/kconfig/conf --silentoldconfig Kconfig CHK include/config.h UPD include/config.h GEN include/autoconf.mk cc1: error: bad value (armv4) for -march= switch /home/k/work/02-uboot/uboot2014.10/scripts/Makefile.autoconf:64: recipe for target 'include/autoconf.mk' failed make[2]: *** [include/autoconf.mk] Error 1 /home/k/work/02-uboot/uboot2014.10/Makefile:466: recipe for target 'silentoldconfig' failed make[1]: *** [silentoldconfig] Error 1 make: *** No rule to make target 'include/config/auto.conf', needed by 'include/config/uboot.release'. Stop. k@localhost ~/w/0/uboot2014.10>
猜測是ifeq那個判斷不成立，所以導致工具鏈沒有指定，所以我用下面命令執行：
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi-
也可以修改Makefile如下：
ARCH = arm CROSS_COMPILE ?= arm-linux-gnueabi- ifeq ($(HOSTARCH),$(ARCH)) CROSS_COMPILE ?= endif
在那個判斷語句上面制定ARCH和CROSS_COMPILE，保存退出然后直接make也可以的。
這次編譯沒問題，但又出現include/linux/compiler-gcc.h:106:30: fatal error: linux/compiler-gcc5.h：No such file or directory的錯誤，原因是ubuntu的版本太高了，網上下載不到這個文件，也有人提出了其它的處理方式，我是直接執行下面命令：
k@localhost ~/w/0/uboot2014.10> cd include/linux/ k@localhost ~/w/0/u/i/linux> cp compiler-gcc4.h compiler-gcc5.h
再次執行make，運行又有地方報錯：
arch/arm/lib/board.c:67:6: error: ‘coloured_LED_init’ aliased to external symbol ‘__coloured_LED_init’ void coloured_LED_init(void)__attribute__((weak, alias("__coloured_LED_init"))); ^ arch/arm/lib/board.c:83:6: error: ‘blue_led_off’ aliased to external symbol ‘__blue_led_off’ void blue_led_off(void) __attribute__((weak, alias("__blue_led_off"))); ^ arch/arm/lib/board.c:81:6: error: ‘blue_led_on’ aliased to external symbol ‘__blue_led_on’ void blue_led_on(void) __attribute__((weak, alias("__blue_led_on"))); ^ arch/arm/lib/board.c:79:6: error: ‘yellow_led_off’ aliased to external symbol ‘__yellow_led_off’ void yellow_led_off(void) __attribute__((weak, alias("__yellow_led_off"))); ^ arch/arm/lib/board.c:77:6: error: ‘yellow_led_on’ aliased to external symbol ‘__yellow_led_on’ void yellow_led_on(void) __attribute__((weak, alias("__yellow_led_on"))); ^ arch/arm/lib/board.c:75:6: error: ‘green_led_off’ aliased to external symbol ‘__green_led_off’ void green_led_off(void) __attribute__((weak, alias("__green_led_off"))); ^ arch/arm/lib/board.c:73:6: error: ‘green_led_on’ aliased to external symbol ‘__green_led_on’ void green_led_on(void) __attribute__((weak, alias("__green_led_on"))); ^ arch/arm/lib/board.c:71:6: error: ‘red_led_off’ aliased to external symbol ‘__red_led_off’ void red_led_off(void) __attribute__((weak, alias("__red_led_off"))); ^ arch/arm/lib/board.c:69:6: error: ‘red_led_on’ aliased to external symbol ‘__red_led_on’ void red_led_on(void) __attribute__((weak, alias("__red_led_on"))); ^ scripts/Makefile.build:275: recipe for target 'arch/arm/lib/board.o' failed make[1]: *** [arch/arm/lib/board.o] Error 1 Makefile:1037: recipe for target 'arch/arm/lib' failed make: *** [arch/arm/lib] Error 2
這是因為內聯函數不能為weak屬性，直接將這些函數注釋掉算了：
inline void __coloured_LED_init(void) {} //void coloured_LED_init(void)__attribute__((weak, alias("__coloured_LED_init"))); inline void __red_led_on(void) {} //void red_led_on(void) __attribute__((weak, alias("__red_led_on"))); inline void __red_led_off(void) {} //void red_led_off(void) __attribute__((weak, alias("__red_led_off"))); inline void __green_led_on(void) {} //void green_led_on(void) __attribute__((weak, alias("__green_led_on"))); inline void __green_led_off(void) {} //void green_led_off(void) __attribute__((weak, alias("__green_led_off"))); inline void __yellow_led_on(void) {} //void yellow_led_on(void) __attribute__((weak, alias("__yellow_led_on"))); inline void __yellow_led_off(void) {} //void yellow_led_off(void) __attribute__((weak, alias("__yellow_led_off"))); inline void __blue_led_on(void) {} //void blue_led_on(void) __attribute__((weak, alias("__blue_led_on"))); inline void __blue_led_off(void) {} //void blue_led_off(void) __attribute__((weak, alias("__blue_led_off")));
再次make
arch/arm/lib/built-in.o: In function `clbss_l': /home/k/work/02-uboot/uboot2014.10/arch/arm/lib/crt0.S:122: undefined reference to `coloured_LED_init' /home/k/work/02-uboot/uboot2014.10/arch/arm/lib/crt0.S:123: undefined reference to `red_led_on' arm-linux-gnueabi-ld.bfd: BFD (GNU Binutils for Ubuntu) 2.26.1 assertion fail ../../bfd/elf32-arm.c:8472 arm-linux-gnueabi-ld.bfd: BFD (GNU Binutils for Ubuntu) 2.26.1 assertion fail ../../bfd/elf32-arm.c:8472 arm-linux-gnueabi-ld.bfd: error: required section '.rel.plt' not found in the linker script arm-linux-gnueabi-ld.bfd: final link failed: Invalid operation Makefile:1019: recipe for target 'u-boot' failed make: *** [u-boot] Error 1
剛才將函數注釋掉了，現在當然報錯了。
# bl coloured_LED_init
# bl red_led_on
直接注釋掉了。
再次make，終於沒問題了。