l4bench errors

Hi,
I am a newbie, trying to run l4bench on ARM. While compilng i get
these errors, does any body know what is the problem. I am using nicta
toolchain for ARM.
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/opt/nicta/tools/gcc-3.4.4-glibc-2.3.5/arm-linux/bin/arm-linux-ld -r
-N build/rootserver/libs/c/crt/sys-l4_rootserver/arch-arm/crt0.o
build/rootserver/l4bench/src/l4bench.o
build/rootserver/l4bench/src/bench_myself.o
build/rootserver/l4bench/src/xscale_counters.o
build/rootserver/l4bench/src/bench_memcpy.o
build/rootserver/l4bench/src/bench_ipc.o
build/rootserver/l4bench/src/bench_zerosleep.o
build/rootserver/l4bench/src/bench_threadcontrol.o
build/rootserver/l4bench/src/bench_exreg.o
build/rootserver/l4bench/src/skyeye.o
build/rootserver/l4bench/src/l4_counters.o -Lbuild/rootserver/libs/c
-Llibs/c -Lbuild/rootserver/libs/elf -Llibs/elf
-L/opt/nicta/tools/gcc-3.4.4-glibc-2.3.5/arm-linux/lib/gcc/arm-linux/3.4.4
-Lbuild/rootserver/libs/bench -Llibs/bench -Lbuild/rootserver/libs/l4
-Llibs/l4 -Lbuild/rootserver/libs/l4e -Llibs/l4e -\( -lc -lelf -lgcc
-lbench -ll4 -ll4e -\) -o build/rootserver/l4bench/l4bench
=> Relocating build/rootserver/l4bench/l4bench.reloc
build/rootserver/l4bench/l4bench(.text+0xc): In function `pong_thread_fass':
l4bench/src/bench_ipc.c:232: undefined reference to `_stack_top'
<string>:422: DeprecationWarning: raising a string exception is deprecated
scons: *** [build/rootserver/l4bench/l4bench.reloc] Exception
Traceback (most recent call last):
  File "/usr/lib/scons/SCons/Taskmaster.py", line 101, in execute
    self.targets[0].build()
  File "/usr/lib/scons/SCons/Node/__init__.py", line 201, in build
    apply(executor, (self, errfunc), kw)
  File "/usr/lib/scons/SCons/Executor.py", line 115, in __call__
    apply(action, (self.targets, self.sources, env, errfunc), kw)
  File "/usr/lib/scons/SCons/Action.py", line 243, in __call__
    stat = self.execute(target, source, env)
  File "/usr/lib/scons/SCons/Action.py", line 512, in execute
    return self.execfunction(target=target, source=rsources, env=env)
  File "tools/build.py", line 422, in __call__
    raise "Linking error", cmd
Linking error: /opt/nicta/tools/gcc-3.4.4-glibc-2.3.5/arm-linux/bin/arm-linux-ld
-Ttext=0xa0540000 build/rootserver/l4bench/l4bench -o
build/rootserver/l4bench/l4bench.reloc
scons: building terminated because of errors.
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