[U-Boot] Switch from mmcboot to ramboot?

[Grant]

> > How can I tell u-boot to boot with the ramboot= definition instead of
> > mmcboot= ?
> >
> > - Grant
>
> You need to change environmental variable bootcmd
>
> setenv bootcmd ramboot
> saveenv
> run bootcmd
>
> or simpler:
>
> Stop u-boot -> and access prompt
>
> then,
>
> run ramboot

Hi Lucasz, that didn't work for me and I think it's because of the
variables set by 'make am335x_evm_defconfig'.  It seems like there are a
set of standard u-boot commands and a higher level of variables set by 'make
am335x_evm_defconfig' which appear in include/configs/am335x_evm.h and
prevent you from using the standard u-boot commands in uEnv.txt.

For example, even after adding the following to the top of my uEnv.txt:

setenv bootcmd ramboot
saveenv

I still get:

"Booting from mmc ..."

I'm struggling to figure out how to use the framework provided by 'make
am335x_evm_defconfig' in uEnv.txt.  Can you point me to info on how to do
that?

- Grant