olaf@pomegranate:/dev/shm/r/linux-2.6.13> make ARCH=ppc O=../O -j12 
  Using /dev/shm/r/linux-2.6.13 as source for kernel
  CHK     /dev/shm/r/O/include/linux/version.h
  SYMLINK /dev/shm/r/O/include/asm -> include/asm-ppc
  GEN    /dev/shm/r/O/Makefile
make[1]: *** No rule to make target `include/linux/version.h', needed by
`arch/ppc/kernel/asm-offsets.s'.  Stop.
make[1]: *** Waiting for unfinished jobs....
make[1]: *** Waiting for unfinished jobs....
  UPD     /dev/shm/r/O/include/linux/version.h
  GEN    /dev/shm/r/O/Makefile
scripts/kconfig/conf -s arch/ppc/Kconfig
make[3]: *** [silentoldconfig] Interrupt
make[2]: *** [silentoldconfig] Interrupt
make[1]: *** [/dev/shm/r/O/include/linux/autoconf.h] Interrupt
make: *** [_all] Interrupt

olaf@pomegranate:/dev/shm/r/linux-2.6.13> history | tail
 1017  vi series.conf
 1018  env -i HOME=$HOME /usr/bin/time sh -c 'rm -rf /dev/shm/r ;
SCRATCH_AREA=/dev/shm/r ./scripts/sequence-patch.sh --quilt  '
 1019  cvs up
 1020  w
 1021  cd /dev/shm/r/linux-2.6.13
 1022  mkdir ../O
 1023  cp arch/ppc/defconfig.default ../O/.config
 1024  make ARCH=ppc O=../O -j12 oldconfig
 1025  make ARCH=ppc O=../O -j12 
 1026  history | tail

this works inside the linux-2.6.13.orig directory:

 1027  cd ../linux-2.6.13.orig/
 1028  make ARCH=ppc O=../O -j12 oldconfig
 1029  make ARCH=ppc O=../O -j12 
 1030  rm -rf ../O/
 1031  mkdir ../O
 1032  cp ../*/arch/ppc/defconfig.default ../O/.config
 1033  make ARCH=ppc O=../O -j12 oldconfig
 1034  make ARCH=ppc O=../O -j12 
 1035  history