This is a small tool that creates an environment image for U-boot.
It can be compiled both as a part of U-boot (using host compiler) and
stand alone. The tool is intended to run on the host and not the target.

Syntax:
./mk_envimg [-d] output_file [input_file]

When invoking the program, input arguments can be specified.
* -d          : debug mode, adds debug printouts
* output_file : specify the name and location of the outpout
* input_file  : input configuration file (optional)

The output file is an ordinary environment binary with a crc32 sum
followed by the environment variables

By default this tool will create an image with the default environment
variables as built-in in U-boot.
If an input file is specified it will remove, modify and/or remove
default environment variables.

Input file examples:
* Add a new variable -> write the new variable and its value:
an_new_variable=a_new_value

* Remove the variable bootargs -> write its name without a value:
bootargs

* Modify the variable bootargs -> write its name with a new value:
bootargs=a_new_value

* Comments -> add # at the beginning of the line
# This is a comment