[U-Boot-Users] How can I reserve memory for LCD framebuffer on ARM-based board?

Hello, I'm working on support for LCD framebuffer on S3C24[14]0 ARM-based SoCs in u-boot. I faced the problem that existing code in lib_arm/board.c uses memory just behind .bss for framebuffer and don't even tries to ensure that there are enough memory (yes, my hardware uses system memory for framebuffer). What can I do to reserve enough memory? Should I somehow relocate .bss (and code)? or should I reserve memory under u-boot code? (that is what lcd_setmem() expects as far as I can understand)

Thanks in advance, Ilya.