CBFSTOOL(8) System Administration Utilities CBFSTOOL(8)

cbfstool - Management utility for CBFS formatted ROM images (coreboot tools)

cbfstool [-h]
cbfstool FILE COMMAND [-v] [PARAMETERS]...

Management utility for CBFS formatted ROM images

Do not search for header; use this offset*

-T

Output top-aligned memory address

-u

Accept short data; fill upward/from bottom
Accept short data; fill downward/from top
Force action
Generate position and alignment arguments
Unprocessed; don't decompress or make ELF
Provide verbose output (-v=INFO -vv=DEBUG output)
Display this help message
Base of extended decode window in host address space(x86 only)
Size of extended decode window in host address space(x86 only)

[-c compression] [-b base-address | -a alignment] [-p padding size] [-y|--xip if TYPE is FSP] [-j topswap-size] (Intel CPUs only) [--ibb] [--ext-win-base win-base --ext-win-size win-size]

Add a component

-j valid size: 0x10000 0x20000 0x40000 0x80000 0x100000

[-c compression] [-b base-address] (linux specific: [-C cmdline] [-I initrd])

Add a payload to the ROM

[-c compression] [-b base] [-S comma-separated-section(s)-to-ignore] [-a alignment] [-Q|--pow2page] [-y|--xip] [--ibb] [--ext-win-base win-base --ext-win-size win-size]

Add a stage to the ROM

[-A hash] -l load-address -e entry-point [-c compression] [-b base]

Add a 32bit flat mode binary

Add a raw 64-bit integer value

Add a legacy CBFS master header

Remove a component

Defragment CBFS image.

Create a copy (duplicate) cbfs instance in fmap

[-o CBFS offset] [-H header offset] [-B bootblock]

Create a legacy ROM file with CBFS master header*

Create a new-style partitioned firmware image

List mutable (or, with -w, readable) image regions

Show the contents of the ROM

Extracts a file from ROM

Write file into same-size [or larger] raw region

Extract raw region contents into binary file

Truncate CBFS and print new size on stdout

Expand CBFS to span entire region

Numbers accompanying -b, -H, and -o switches* may be provided in two possible formats: if their value is greater than 0x80000000, they are interpreted as a top-aligned x86 memory address; otherwise, they are treated as an offset into flash.

arm64, arm, mips, ppc64, power8, riscv, x86, unknown

bootblock, cbfs header, legacy stage, stage, simple elf, fit_payload, optionrom, bootsplash, raw, vsa, mbi, microcode, intel_fit, fsp, mrc, cmos_default, cmos_layout, spd, mrc_cache, mma, efi, struct, deleted, null, amdfw

Note that these actions and switches are only valid when working with legacy images whose structure is described primarily by a CBFS master header. New-style images, in contrast, exclusively make use of an FMAP to describe their layout: this must minimally contain an 'FMAP' section specifying the location of this FMAP itself and a 'COREBOOT' section describing the primary CBFS. It should also be noted that, when working with such images, the -F and -r switches default to 'COREBOOT' for convenience, and the -b switch becomes relative to the selected CBFS region's lowest address. The one exception to this rule is the top-aligned address, which is always relative to the end of the entire image rather than relative to the local region; this is true for for both input (sufficiently large) and output (-T) data.

coresystems GmbH.
Man page written by Ahmad Khalifa.
November 2024