[U-Boot] Compiling U-Boot

[Alexey Smishlayev]

Hello!
I would like to compile U-Boot with custom configuration.
I downloaded source from the master git repository 
(http://git.denx.de/?p=u-boot.git;a=summary).
I am trying to compile using following commands:
$ cd u-boot/
$ make ARCH=arm CROSS_COMPILE=arm-unknown-linux-gnu- 
at91sam9g20ek_nandflash_config
$ make ARCH=arm CROSS_COMPILE=arm-unknown-linux-gnu- all

It goes on for a while, and then I get the error:
crt0.S: Assembler messages:
crt0.S:70: Error: register expected, not '#(184)' -- `sub sp,#(184)'
make[1]: *** [crt0.o] Error 1
make[1]: Leaving directory `/root/u-boot/arch/arm/lib'
make: *** [arch/arm/lib/built-in.o] Error 2

The "arm-unknown-linux-gnu-" is a toolchain prefix for my devboard.
I am trying to compile on 64bit Ubuntu computer. I have also tried 32bit 
debian lenny virtual machine.
Can I correct this error or is there something I am doing wrong?

Best regards,
Alexey Smishlayev