"defines" in linker script

[Massimiliano Cialdi]

I want something like:

VDIM = 2K;

MEMORY
{
	rom_vect : ORIGIN = 0x00000000, LENGTH = VDIM
	rom      : ORIGIN = VDIM,       LENGTH = 256K - VDIM
	ext_ram  : ORIGIN = 0x00420000, LENGTH = 131072
	ram      : ORIGIN = 0x00FFB000, LENGTH = 16320
	ram1     : ORIGIN = 0x00FFFFC0, LENGTH = 64
}

obviously this doesn't work. ld report 
"nonconstant expression for length"

So I wonder if there is something like #define in linker script.

thanks

-- 
Massimiliano Cialdi
cialdi@firenze.net
m.cialdi@oksys.it