[PATCH v3 5/5] doc:eficonfig: add description for UEFI Secure Boot Configuration

[Ilias Apalodimas]

On Fri, Dec 02, 2022 at 01:59:37PM +0900, Masahisa Kojima wrote:
> This commits add the description for the UEFI Secure Boot
> Configuration through the eficonfig menu.
> 
> Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
> ---
> No update since v2
> 
> Newly created in v2
> 
>  doc/usage/cmd/eficonfig.rst | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)
> 
> diff --git a/doc/usage/cmd/eficonfig.rst b/doc/usage/cmd/eficonfig.rst
> index 340ebc80db..67c859964f 100644
> --- a/doc/usage/cmd/eficonfig.rst
> +++ b/doc/usage/cmd/eficonfig.rst
> @@ -31,6 +31,9 @@ Change Boot Order
>  Delete Boot Option
>      Delete the UEFI Boot Option
>  
> +Secure Boot Configuration
> +    Edit UEFI Secure Boot Configuration
> +
>  Configuration
>  -------------
>  
> @@ -44,6 +47,16 @@ U-Boot console. In this case, bootmenu can be used to invoke "eficonfig"::
>      CONFIG_USE_PREBOOT=y
>      CONFIG_PREBOOT="setenv bootmenu_0 UEFI Maintenance Menu=eficonfig"
>  
> +UEFI specification requires that UEFI Secure Boot Configuration (especially
> +for PK and KEK) is stored in non-volatile storage which is tamper resident.

s/resident/resistant

> +CONFIG_EFI_MM_COMM_TEE is mandatory to provide the secure storage in U-Boot.

Can we be a bit more clear here. Something along the lines of 
"The only way U-Boot can currently store EFI variables on a tamper
resistant medium is via OP-TEE.  The Kconfig option that enables that is 
CONFIG_EFI_MM_COMM_TEE and ends up storing EFI variables on an RPMB
partition of an eMMC"

> +UEFI Secure Boot Configuration menu entry is enabled when the following
> +options are enabled::
> +
> +    CONFIG_EFI_SECURE_BOOT=y
> +    CONFIG_EFI_MM_COMM_TEE=y
> +
> +
>  How to boot the system with newly added UEFI Boot Option
>  ''''''''''''''''''''''''''''''''''''''''''''''''''''''''
>  
> @@ -66,6 +79,15 @@ add "bootefi bootmgr" entry as a default or first bootmenu entry::
>  
>      CONFIG_PREBOOT="setenv bootmenu_0 UEFI Boot Manager=bootefi bootmgr; setenv bootmenu_1 UEFI Maintenance Menu=eficonfig"
>  
> +UEFI Secure Boot Configuration
> +''''''''''''''''''''''''''''''
> +
> +User can enroll PK, KEK, db and dbx by selecting file.

selecting a file

> +"eficonfig" command only accepts the signed EFI Signature List(s)
> +with an authenticated header, typically ".auth" file.
> +To clear the PK, KEK, db and dbx, user needs to enroll the null key
> +signed by PK or KEK.
> +
>  See also
>  --------
>  * :doc:`bootmenu<bootmenu>` provides a simple mechanism for creating menus with different boot items
> -- 
> 2.17.1
> 

Thanks
/Ilias