If you encounter this error while compiling a newer kernel:

  CC      init/calibrate.o
  LD      init/built-in.o
  HOSTCC  usr/gen_init_cpio
  /usr/src/linux-3.2.12-gentoo/scripts/gen_initramfs_list.sh: Cannot open '/usr/share/v86d/initramfs'
make[1]: *** [usr/initramfs_data.cpio] Error 1
make: *** [usr] Error 2

Emerge v86d:

# emerge v86d

Credit due: big my secret: Problem of make kernel about v86d initramfs