[U-Boot] [u-boot]automatic reset of variables to defaults

[Dennis Borgmann <dennis.borgmann@googlemail.com>]

Hello u-boot users list,

I am experiencing a problem concerning variables being set and later 
getting lost.

In order to boot a Linux on a quite small plattform (Eddy CPU: 
http://sysbas.en.ec21.com/Embedded_CPU_Module--1904028_1904479.html ), I 
have to reset the variable "OS_SDRAM" from its initial value of 
"0x20000000" to "0x21000000". If I don't do so, the bootloader reports 
problems extracting my kernel. This must be due to my kernel being 
bigger than expected by u-boot.

These are the steps, that I take:

[code]
setenv OS_SDRAM 0x21000000
saveenv
reset
[/code]

Anyway, this way, it works fine.

Sometimes, the bootloader looses this configuration and resets its 
variable "OS_SDRAM" back to its default value. Once, the bootloader has 
reset this value, it cannot boot anymore(well, of course not, since I 
had to manually alter this value in order to make it boot my linux).

Annoyingly, I cannot surely reproduce this error. I tried rebooting it 
over 3 days in 2-minute-steps and the error won't occur. In addition, I 
tried giving random input to the console of u-boot for 3 days (again in 
2-minute-steps) and still the error won't come up.

Two questions:

1. What else might be the cause of this?

2. How could I prevent u-boot from resetting to its default value?

I'd be happy for any kind of help.

Best regards,
Dennis