Rebuilding boot loader under 7.0-STABLE

[Gianni]

Hi
I've got 7.0-STABLE installed on an embedded Soekris 5501 box and I'm  
trying to rebuild the boot loader to not use terminal emulation so I  
can read the boot messages and menu, as per:
https://neon1.net/misc/minibsd.html#t3

# cd /sys/boot
# make clean && make

Gives the following error:

make: don't know how to make /usr/src/sys/boot/i386/gptboot/../btx/lib/ 
crt0.o. Stop
*** Error code 2
Stop in /usr/src/sys/boot/i386.
*** Error code 1
Stop in /usr/src/sys/boot.

The sources are recently csup'd, I'd appreciate some help.
Thanks
Gianni