user@foobar ~/coreboot $ cbfstool build/coreboot.rom print
FMAP REGION: COREBOOT
Name                           Offset     Type           Size   Comp
cbfs master header             0x0        cbfs header        32 none
fallback/romstage              0x80       stage           84948 none
cpu_microcode_blob.bin         0x14cc0    microcode       25600 none
fallback/ramstage              0x1b140    stage          112178 none
config                         0x367c0    raw               244 none
revision                       0x36900    raw               679 none
cmos.default                   0x36c00    cmos_default      256 none
cmos_layout.bin                0x36d40    cmos_layout      1980 none
fallback/postcar               0x37540    stage           21284 none
fallback/dsdt.aml              0x3c8c0    raw             14479 none
fallback/payload               0x401c0    simple elf     716619 none
(empty)                        0xef180    null          1765976 none
bootblock                      0x29e400   bootblock        3016 none

user@foobar ~/coreboot $ nvramtool -C build/coreboot.rom -a
ERROR: No valid CBFS header found!
CBFS:  Could not find file cmos.default
Need a cmos.default in the CBFS image or separate cmos file (-D).