---
name: "vbutil_kernel"
section: "1"
platform: "linux"
package: "vboot-kernel-utils"
version: "0~R106-15054.B+dfsg-0.1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/vbutil_kernel"
---

# vbutil\_kernel(1)

Utility to sign custom kernels to boot with Chrome OS devices

## NAME

vbutil\_kernel - Utility to sign custom kernels to boot with Chrome OS devices

## SYNOPSIS

**futility** */usr/bin/vbutil\_kernel --pack \<file\>* \[*PARAMETERS*\]

## DESCRIPTION

-

  Required parameters:

- **--keyblock** \<file\>

  Key block in .keyblock format

- **--signprivate** \<file\>

  Private key to sign kernel data, in .vbprivk format

- **--version** \<number\>

  Kernel version

- **--vmlinuz** \<file\>

  Linux kernel bzImage file

- **--bootloader** \<file\>

  Bootloader stub

- **--config** \<file\>

  Command line file

- **--arch** \<arch\>

  Cpu architecture (default x86)

-

  Optional:

- **--kloadaddr** \<address\>

  Assign kernel body load address

- **--pad** \<number\>

  Verification padding size in bytes

- **--vblockonly**

  Emit just the verification blob

- **--flags** NUM

  Flags to be passed in the header

OR

Usage:  futility */usr/bin/vbutil\_kernel* **--repack** \<file\> \[PARAMETERS\]

-

  Required parameters:

- **--signprivate** \<file\>

  Private key to sign kernel data, in .vbprivk format

- **--oldblob** \<file\>

  Previously packed kernel blob (including verification blob)

-

  Optional:

- **--keyblock** \<file\>

  Key block in .keyblock format

- **--config** \<file\>

  New command line file

- **--version** \<number\>

  Kernel version

- **--kloadaddr** \<address\>

  Assign kernel body load address

- **--pad** \<number\>

  Verification blob size in bytes

- **--vblockonly**

  Emit just the verification blob

OR

Usage:  futility */usr/bin/vbutil\_kernel* **--verify** \<file\> \[PARAMETERS\]

-

  Optional:

- **--signpubkey** \<file\>

  Public key to verify kernel keyblock, in .vbpubk format

- **--verbose**

  Print a more detailed report

- **--keyblock** \<file\>

  Outputs the verified key block, in .keyblock format

- **--pad** \<number\>

  Verification padding size in bytes

- **--minversion** \<number\>

  Minimum combined kernel key version

OR

Usage:  futility */usr/bin/vbutil\_kernel* **--get-vmlinuz** \<file\> \[PARAMETERS\]

-

  Required parameters:

- **--vmlinuz-out** \<file\>

  vmlinuz image output file

Usage:  futility */usr/bin/vbutil\_kernel* **--pack** \<file\> \[PARAMETERS\]

-

  Required parameters:

- **--keyblock** \<file\>

  Key block in .keyblock format

- **--signprivate** \<file\>

  Private key to sign kernel data, in .vbprivk format

- **--version** \<number\>

  Kernel version

- **--vmlinuz** \<file\>

  Linux kernel bzImage file

- **--bootloader** \<file\>

  Bootloader stub

- **--config** \<file\>

  Command line file

- **--arch** \<arch\>

  Cpu architecture (default x86)

-

  Optional:

- **--kloadaddr** \<address\>

  Assign kernel body load address

- **--pad** \<number\>

  Verification padding size in bytes

- **--vblockonly**

  Emit just the verification blob

- **--flags** NUM

  Flags to be passed in the header

OR

Usage:  futility */usr/bin/vbutil\_kernel* **--repack** \<file\> \[PARAMETERS\]

-

  Required parameters:

- **--signprivate** \<file\>

  Private key to sign kernel data, in .vbprivk format

- **--oldblob** \<file\>

  Previously packed kernel blob (including verification blob)

-

  Optional:

- **--keyblock** \<file\>

  Key block in .keyblock format

- **--config** \<file\>

  New command line file

- **--version** \<number\>

  Kernel version

- **--kloadaddr** \<address\>

  Assign kernel body load address

- **--pad** \<number\>

  Verification blob size in bytes

- **--vblockonly**

  Emit just the verification blob

OR

Usage:  futility */usr/bin/vbutil\_kernel* **--verify** \<file\> \[PARAMETERS\]

-

  Optional:

- **--signpubkey** \<file\>

  Public key to verify kernel keyblock, in .vbpubk format

- **--verbose**

  Print a more detailed report

- **--keyblock** \<file\>

  Outputs the verified key block, in .keyblock format

- **--pad** \<number\>

  Verification padding size in bytes

- **--minversion** \<number\>

  Minimum combined kernel key version

OR

Usage:  futility */usr/bin/vbutil\_kernel* **--get-vmlinuz** \<file\> \[PARAMETERS\]

-

  Required parameters:

- **--vmlinuz-out** \<file\>

  vmlinuz image output file