[tduffy@duffman linux-2.6.9-bk-openib]$ make O=/build1/tduffy/openib-work/build/bk/3.4/x86_64/
  Using /build1/tduffy/openib-work/linux-2.6.9-bk-openib as source for kernel
  CHK     include/linux/version.h
make[2]: `arch/x86_64/kernel/asm-offsets.s' is up to date.
  CHK     include/asm-x86_64/offset.h
  CHK     include/linux/compile.h
  GEN_INITRAMFS_LIST usr/initramfs_list
Using shipped usr/initramfs_list
  CPIO    usr/initramfs_data.cpio
ERROR: unable to open 'usr/initramfs_list': No such file or directory

Usage:
        ./usr/gen_init_cpio <cpio_list>

<cpio_list> is a file containing newline separated entries that
describe the files to be included in the initramfs archive:

# a comment
file <name> <location> <mode> <uid> <gid>
dir <name> <mode> <uid> <gid>
nod <name> <mode> <uid> <gid> <dev_type> <maj> <min>

<name>      name of the file/dir/nod in the archive
<location>  location of the file in the current filesystem
<mode>      mode/permissions of the file
<uid>       user id (0=root)
<gid>       group id (0=root)
<dev_type>  device type (b=block, c=character)
<maj>       major number of nod
<min>       minor number of nod

example:
# A simple initramfs
dir /dev 0755 0 0
nod /dev/console 0600 0 0 c 5 1
dir /root 0700 0 0
dir /sbin 0755 0 0
file /sbin/kinit /usr/src/klibc/kinit/kinit 0755 0 0
make[2]: *** [usr/initramfs_data.cpio] Error 1
make[1]: *** [usr] Error 2
make: *** [_all] Error 2