[U-Boot] Question about mem parameter in the bootargs

Hi,

Does someone knows what is the smallest step to increase the mem parameter in the bootargs?

I am dealing with an embedded system based on an ARM LPC3250 and running linux. I have a very critical memory constraint and I would like to have mem=3584k instead mem=3M or mem=4M.

The Linux boot up sucessfull with mem=3M or mem=4M but the kernel crashes with mem=3584k.

thank you

Moratelli