主要问题是 undefined reference to `serial_putc' 串口的这一系列函数找不到。
有谁遇到过吗？如何解决？
顺便牢骚一句，友善虽然提供了可用的BOOTLOADER，但不提供开放源码的可用的BOOTLOADER，这个事情太扯了，不利于学习和开发。
我们要的BOOT LOADER可能不需要那么完善，但需要一个能用的没那么复杂的，简单说能挂NFS调试LINUX的文件系统就好啦。
所以只有自己找，自己折腾了呗。
make[1]: Leaving directory `/root/opencsbc-u-boot/arch/arm/cpu/armv7'
UNDEF_SYM=`arm-linux-objdump -x board/samsung/mini210/libmini210.o api/libapi.o arch/arm/cpu/armv7/libarmv7.o arch/arm/cpu/armv7/s5p-common/libs5p-common.o arch/arm/cpu/armv7/s5pc1xx/libs5pc1xx.o arch/arm/lib/libarm.o common/libcommon.o disk/libdisk.o drivers/bios_emulator/libatibiosemu.o drivers/block/libblock.o drivers/dma/libdma.o drivers/fpga/libfpga.o drivers/gpio/libgpio.o drivers/hwmon/libhwmon.o drivers/i2c/libi2c.o drivers/input/libinput.o drivers/misc/libmisc.o drivers/mmc/libmmc.o drivers/mtd/libmtd.o drivers/mtd/nand/libnand.o drivers/mtd/onenand/libonenand.o drivers/mtd/spi/libspi_flash.o drivers/mtd/ubi/libubi.o drivers/net/libnet.o drivers/net/phy/libphy.o drivers/pci/libpci.o drivers/pcmcia/libpcmcia.o drivers/power/libpower.o drivers/rtc/librtc.o drivers/serial/libserial.o drivers/spi/libspi.o drivers/twserial/libtws.o drivers/usb/eth/libusb_eth.o drivers/usb/gadget/libusb_gadget.o drivers/usb/host/libusb_host.o drivers/usb/musb/libusb_musb.o drivers/usb/phy/libusb_phy.o drivers/video/libvideo.o drivers/watchdog/libwatchdog.o fs/cramfs/libcramfs.o fs/ext2/libext2fs.o fs/fat/libfat.o fs/fdos/libfdos.o fs/jffs2/libjffs2.o fs/reiserfs/libreiserfs.o fs/ubifs/libubifs.o fs/yaffs2/libyaffs2.o lib/libfdt/libfdt.o lib/libgeneric.o lib/lzma/liblzma.o lib/lzo/liblzo.o lib/zlib/libz.o net/libnet.o post/libpost.o | sed -n -e 's/.*\(__u_boot_cmd_.*\)/-u\1/p'|sort|uniq`; cd /root/opencsbc-u-boot && arm-linux-ld -pie -T u-boot.lds -Bstatic $UNDEF_SYM arch/arm/cpu/armv7/start.o --start-group api/libapi.o arch/arm/cpu/armv7/libarmv7.o arch/arm/cpu/armv7/s5p-common/libs5p-common.o arch/arm/cpu/armv7/s5pc1xx/libs5pc1xx.o arch/arm/lib/libarm.o common/libcommon.o disk/libdisk.o drivers/bios_emulator/libatibiosemu.o drivers/block/libblock.o drivers/dma/libdma.o drivers/fpga/libfpga.o drivers/gpio/libgpio.o drivers/hwmon/libhwmon.o drivers/i2c/libi2c.o drivers/input/libinput.o drivers/misc/libmisc.o drivers/mmc/libmmc.o drivers/mtd/libmtd.o drivers/mtd/nand/libnand.o drivers/mtd/onenand/libonenand.o drivers/mtd/spi/libspi_flash.o drivers/mtd/ubi/libubi.o drivers/net/libnet.o drivers/net/phy/libphy.o drivers/pci/libpci.o drivers/pcmcia/libpcmcia.o drivers/power/libpower.o drivers/rtc/librtc.o drivers/serial/libserial.o drivers/spi/libspi.o drivers/twserial/libtws.o drivers/usb/eth/libusb_eth.o drivers/usb/gadget/libusb_gadget.o drivers/usb/host/libusb_host.o drivers/usb/musb/libusb_musb.o drivers/usb/phy/libusb_phy.o drivers/video/libvideo.o drivers/watchdog/libwatchdog.o fs/cramfs/libcramfs.o fs/ext2/libext2fs.o fs/fat/libfat.o fs/fdos/libfdos.o fs/jffs2/libjffs2.o fs/reiserfs/libreiserfs.o fs/ubifs/libubifs.o fs/yaffs2/libyaffs2.o lib/libfdt/libfdt.o lib/libgeneric.o lib/lzma/liblzma.o lib/lzo/liblzo.o lib/zlib/libz.o net/libnet.o post/libpost.o board/samsung/mini210/libmini210.o --end-group /root/opencsbc-u-boot/arch/arm/lib/eabi_compat.o -L /opt/FriendlyARM/toolschain/4.5.1/lib/gcc/arm-none-linux-gnueabi/4.5.1 -lgcc -Map u-boot.map -o u-boot
arch/arm/lib/libarm.o: In function `board_init_r':
/root/opencsbc-u-boot/arch/arm/lib/board.c:463: undefined reference to `serial_initialize'
arch/arm/lib/libarm.o: In function `arch_lmb_reserve':
/root/opencsbc-u-boot/arch/arm/lib/bootm.c:79: undefined reference to `lmb_reserve'
arch/arm/lib/libarm.o:(.data+0x8): undefined reference to `env_init'
arch/arm/lib/libarm.o:(.data+0x10): undefined reference to `serial_init'
common/libcommon.o: In function `do_load_serial_bin':
/root/opencsbc-u-boot/common/cmd_load.c:470: undefined reference to `serial_setbrg'
/root/opencsbc-u-boot/common/cmd_load.c:508: undefined reference to `serial_setbrg'
common/libcommon.o: In function `do_env_save':
/root/opencsbc-u-boot/common/cmd_nvedit.c:552: undefined reference to `saveenv'
/root/opencsbc-u-boot/common/cmd_nvedit.c:553: undefined reference to `env_name_spec'
common/libcommon.o: In function `_do_env_set':
/root/opencsbc-u-boot/common/cmd_nvedit.c:248: undefined reference to `serial_assign'
/root/opencsbc-u-boot/common/cmd_nvedit.c:293: undefined reference to `serial_setbrg'
common/libcommon.o: In function `serial_printf':
/root/opencsbc-u-boot/common/console.c:218: undefined reference to `serial_puts'
common/libcommon.o: In function `getc':
/root/opencsbc-u-boot/common/console.c:307: undefined reference to `serial_getc'
common/libcommon.o: In function `tstc':
/root/opencsbc-u-boot/common/console.c:323: undefined reference to `serial_tstc'
common/libcommon.o: In function `putc':
/root/opencsbc-u-boot/common/console.c:343: undefined reference to `serial_putc'
common/libcommon.o: In function `puts':
/root/opencsbc-u-boot/common/console.c:364: undefined reference to `serial_puts'
common/libcommon.o: In function `env_get_char_init':
/root/opencsbc-u-boot/common/env_common.c:140: undefined reference to `env_get_char_spec'
common/libcommon.o: In function `env_relocate':
/root/opencsbc-u-boot/common/env_common.c:245: undefined reference to `env_relocate_spec'
common/libcommon.o: In function `boot_ramdisk_high':
/root/opencsbc-u-boot/common/image.c:1060: undefined reference to `lmb_reserve'
/root/opencsbc-u-boot/common/image.c:1063: undefined reference to `lmb_alloc_base'
/root/opencsbc-u-boot/common/image.c:1065: undefined reference to `lmb_alloc'
common/libcommon.o: In function `main_loop':
/root/opencsbc-u-boot/common/main.c:316: undefined reference to `u_boot_hush_start'
/root/opencsbc-u-boot/common/main.c:382: undefined reference to `parse_string_outer'
/root/opencsbc-u-boot/common/main.c:410: undefined reference to `parse_file_outer'
common/libcommon.o: In function `run_command':
/root/opencsbc-u-boot/common/main.c:1381: undefined reference to `do_bootd'
common/libcommon.o: In function `do_run':
/root/opencsbc-u-boot/common/main.c:1404: undefined reference to `parse_string_outer'
common/libcommon.o: In function `stdio_init':
/root/opencsbc-u-boot/common/stdio.c:231: undefined reference to `serial_stdio_init'
/root/opencsbc-u-boot/common/stdio.c:244: undefined reference to `serial_putc'
/root/opencsbc-u-boot/common/stdio.c:244: undefined reference to `serial_puts'
/root/opencsbc-u-boot/common/stdio.c:244: undefined reference to `serial_getc'
/root/opencsbc-u-boot/common/stdio.c:244: undefined reference to `serial_tstc'
drivers/serial/libserial.o: In function `serial_putc_dev':
/root/opencsbc-u-boot/drivers/serial/serial_s5p.c:158: undefined reference to `serial_putc'
arm-linux-ld: BFD (GNU Binutils) 2.20.1.20100303 assertion fail /work/toolchain/build/src/binutils-2.20.1/bfd/elf32-arm.c:12429
/bin/sh: line 1: 7499 Segmentation fault arm-linux-ld -pie -T u-boot.lds -Bstatic $UNDEF_SYM arch/arm/cpu/armv7/start.o --start-group api/libapi.o arch/arm/cpu/armv7/libarmv7.o arch/arm/cpu/armv7/s5p-common/libs5p-common.o arch/arm/cpu/armv7/s5pc1xx/libs5pc1xx.o arch/arm/lib/libarm.o common/libcommon.o disk/libdisk.o drivers/bios_emulator/libatibiosemu.o drivers/block/libblock.o drivers/dma/libdma.o drivers/fpga/libfpga.o drivers/gpio/libgpio.o drivers/hwmon/libhwmon.o drivers/i2c/libi2c.o drivers/input/libinput.o drivers/misc/libmisc.o drivers/mmc/libmmc.o drivers/mtd/libmtd.o drivers/mtd/nand/libnand.o drivers/mtd/onenand/libonenand.o drivers/mtd/spi/libspi_flash.o drivers/mtd/ubi/libubi.o drivers/net/libnet.o drivers/net/phy/libphy.o drivers/pci/libpci.o drivers/pcmcia/libpcmcia.o drivers/power/libpower.o drivers/rtc/librtc.o drivers/serial/libserial.o drivers/spi/libspi.o drivers/twserial/libtws.o drivers/usb/eth/libusb_eth.o drivers/usb/gadget/libusb_gadget.o drivers/usb/host/libusb_host.o drivers/usb/musb/libusb_musb.o drivers/usb/phy/libusb_phy.o drivers/video/libvideo.o drivers/watchdog/libwatchdog.o fs/cramfs/libcramfs.o fs/ext2/libext2fs.o fs/fat/libfat.o fs/fdos/libfdos.o fs/jffs2/libjffs2.o fs/reiserfs/libreiserfs.o fs/ubifs/libubifs.o fs/yaffs2/libyaffs2.o lib/libfdt/libfdt.o lib/libgeneric.o lib/lzma/liblzma.o lib/lzo/liblzo.o lib/zlib/libz.o net/libnet.o post/libpost.o board/samsung/mini210/libmini210.o --end-group /root/opencsbc-u-boot/arch/arm/lib/eabi_compat.o -L /opt/FriendlyARM/toolschain/4.5.1/lib/gcc/arm-none-linux-gnueabi/4.5.1 -lgcc -Map u-boot.map -o u-boot
make: *** [u-boot] Error 139
