arm+uclinux环境搭建， make error!

风吹雪

刚刚开始尝试在搭建arm+linux开发环境，在编译2.6内核的时候出现以下错误，一无所知，请高手们指点一下，谢谢。
enlessy:/home/embeded/uClinux-dist# make
make ARCH=armnommu CROSS_COMPILE=arm-elf- -C linux-2.6.x  || exit 1
make[1]: Entering directory `/home/embeded/uClinux-dist/linux-2.6.x'
  CHK     include/linux/version.h
  UPD     include/linux/version.h
  SPLIT   include/linux/autoconf.h -> include/config/*
  SYMLINK include/asm-armnommu/arch -> include/asm-armnommu/arch-s3c44b0x
make[2]: `arch/armnommu/kernel/asm-offsets.s' is up to date.
make[2]: `include/asm-arm/mach-types.h' is up to date.
  CHK     include/linux/compile.h
  CC      init/version.o
  LD      init/built-in.o
  CC      kernel/sysctl.o
  LD      kernel/built-in.o
  CC      fs/proc/array.o
  CC      fs/proc/proc_misc.o
  LD      fs/proc/proc.o
  LD      fs/proc/built-in.o
  LD      fs/built-in.o
  CC      security/commoncap.o
  LD      security/built-in.o
  GEN     .version
  CHK     include/linux/compile.h
  UPD     include/linux/compile.h
  CC      init/version.o
  LD      init/built-in.o
  LD      vmlinux
arch/armnommu/mach-s3c44b0x/built-in.o(.text+0x140): In function `load_initrd':
/home/embeded/uClinux-dist/linux-2.6.x/arch/armnommu/mach-s3c44b0x/arch.c:86:
undefined reference to `s3c44b0x_led_on'
arch/armnommu/mach-s3c44b0x/built-in.o(.text+0x148):/home/embeded/uClinux-dist/linux-2.6.x/arch/armnommu/mach-s3c44b0x/arch.c:90:
undefined reference to `s3c44b0x_led_off'
make[1]: *** [vmlinux] Error 1
make[1]: Leaving directory `/home/embeded/uClinux-dist/linux-2.6.x'
make: *** [linux] Error 1

arch.c的79-90行代码如下，不知如何修改。
void __init load_initrd(void *src, void *dst, size_t count)
{
int verify = 1;
printk("Load initrd image from flash(%08x) to SDRAM(%08x), Length = %d ...",
src, dst, count);
memmove(dst, src, count);
if (verify) {
  printk("Verify ...");
  printk("%s\n", memcmp(src, dst, count) == 0 ? "Done" : "Failed");
} else {
  printk("Done\n");
}
}
#endif