Error on build uboot and kernal

We are trying to build u boot and kernal from source code with help for this documentation uboot. we install linux arm cross compiler.we are unable to build the uboot. we got following

technomed@technomed:~$ cd u-boot-toradex/
technomed@technomed:~/u-boot-toradex$ export ARCH=arm
technomed@technomed:~/u-boot-toradex$ export PATH=~/gcc-linaro/bin:$PATH
technomed@technomed:~/u-boot-toradex$ export CROSS_COMPILE=arm-linux-gnueabihf-
technomed@technomed:~/u-boot-toradex$ make colibri_imx7_defconfig
# configuration written to .config
# technomed@technomed:~/u-boot-toradex$ make -j3 2>&1 | tee build.log
/home/technomed/gcc-linaro/bin/arm-linux-gnueabihf-gcc: 1: /home/technomed/gcc-linaro/bin/arm-linux-gnueabihf-gcc: ELF: not found
/home/technomed/gcc-linaro/bin/arm-linux-gnueabihf-gcc: 1: /home/technomed/gcc-linaro/bin/arm-linux-gnueabihf-gcc: Syntax error: "(" unexpected (expecting ")")
/home/technomed/gcc-linaro/bin/arm-linux-gnueabihf-gcc: 1: /home/technomed/gcc-linaro/bin/arm-linux-gnueabihf-gcc: ELF: not found
/home/technomed/gcc-linaro/bin/arm-linux-gnueabihf-gcc: 1: /home/technomed/gcc-linaro/bin/arm-linux-gnueabihf-gcc: Syntax error: "(" unexpected (expecting ")")
dirname: missing operand
Try 'dirname --help' for more information.
scripts/kconfig/conf 
--silentoldconfig Kconfig
  CHK     include/config.h
  GEN     include/autoconf.mk.dep
  CFG     u-boot.cfg
/home/technomed/gcc-linaro/bin/arm-linux-gnueabihf-gcc: 1: /home/technomed/gcc-linaro/bin/arm-linux-gnueabihf-gcc: ELF: not found
/home/technomed/gcc-linaro/bin/arm-linux-gnueabihf-gcc: 1: /home/technomed/gcc-linaro/bin/arm-linux-gnueabihf-gcc: Syntax error: "(" unexpected (expecting ")")
/home/technomed/gcc-linaro/bin/arm-linux-gnueabihf-gcc: 1: /home/technomed/gcc-linaro/bin/arm-linux-gnueabihf-gcc: ELF: not found
/home/technomed/gcc-linaro/bin/arm-linux-gnueabihf-gcc: 1: /home/technomed/gcc-linaro/bin/arm-linux-gnueabihf-gcc: Syntax error: "(" unexpected (expecting ")")
scripts/Makefile.autoconf:50: recipe for target 'include/autoconf.mk.dep' failed
make[1]: *** [include/autoconf.mk.dep] Error 1
make[1]: *** Waiting for unfinished jobs....
scripts/Makefile.autoconf:79: recipe for target 'u-boot.cfg' failed
make[1]: *** [u-boot.cfg] Error 1
make: *** No rule to make target 'include/config/auto.conf', needed by 'include/config/uboot.release'.  Stop.

I already build old version colibri imx7 linux 2.6 but we canot able to build 2.7 and 2.8 version. please suggest whar are we missing ?

What compiler are you using? What is the output of:

/home/technomed/gcc-linaro/bin/arm-linux-gnueabihf-gcc --version

I am using linux ubuntu 16.04 i686 bit os. I understand 32 bit version are not support for above 4.9 cross compiler as per documentation.

technomed@technomed:~$ /home/technomed/gcc-linaro/bin/arm-linux-gnueabihf-gcc --version
bash: /home/technomed/gcc-linaro/bin/arm-linux-gnueabihf-gcc: cannot execute binary file: Exec format error

I got error on both 5.2 and 6.2 cross compiler. Is it possible to compile linux image v2.8 using gcc 4.9 cross compiler in 32 bit ubuntu. thanks for your help.

There are i686 version of GCC 5.2 and 6.2 (e.g. gcc-linaro-6.2.1-2016.11-i686_arm-linux-gnueabihf.tar.xz). Those should work fine on 16.04 32-bit OS.

Note that you will likely not be able to compile a complete LXDE OE image using a 32-bit OS due to memory limitations. Toradex recommends using a 64-bit operating system.