Adding custom environment variables to u-boot

Hi there,

I'm really new to all this. I'm using a BeagleBone Rev. A3
I'm currently trying to add a custom command into the u-boot command
line by adding it to the environment values.
I wrote a C standalone program to run a series of memory tests, this
command will run those tests.
It has been tested and working with the BeagleBone Demo Image, but
since I've tried to use the newer source of U-boot.

To build u-boot, I'm currently using the following commands:
make CROSS_COMPILE=arm-none-linux-gnueabi- mrproper
make CROSS_COMPILE=arm-none-linux-gnueabi- omap3_beagle_config
make CROSS_COMPILE=arm-none-linux-gnueabi-

Within my u-boot/include/configs/omap3_beagle.h
I've added the following lines to

"memtest=mmcinfo; \
        fatload mmc 0:1 0x80300000 memtest.bin; \
        go 0x80300018 0x80000000 0x807FFFFF\0" \

After building, I replaced the u-boot.img and MLO files on the
BeagleBone SD.

For some reason, the board does not boot at all?
I'm accessing the board via this command:
sudo screen /dev/`dmesg | grep FTDI | grep "now attached to" | tail

That's for the original BeagleBoard and BeagleBoard xM.

for the BeagleBone use: am335x_evm_config

""BUT"", i know mainline u-boot now has some support for the am335x
devices (more was merged over the weekend), but i haven't personally
tested it yet this morning... but it should work a lot better then