[PATCH v5 04/11] doc: update UEFI document for usage of mkeficapsule

[Simon Glass]

Hi Takahiro,

On Thu, 28 Oct 2021 at 00:25, AKASHI Takahiro
<takahiro.akashi at linaro.org> wrote:
>
> Now we can use mkeficapsule command instead of EDK-II's script
> to create a signed capsule file. So update the instruction for
> capsule authentication.
>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
> ---
>  doc/develop/uefi/uefi.rst | 143 ++++++++++++++++++--------------------
>  1 file changed, 67 insertions(+), 76 deletions(-)

Reviewed-by: Simon Glass <sjg at chromium.org>

thoughts below

>
> diff --git a/doc/develop/uefi/uefi.rst b/doc/develop/uefi/uefi.rst
> index f17138f5c765..864d61734bee 100644
> --- a/doc/develop/uefi/uefi.rst
> +++ b/doc/develop/uefi/uefi.rst
> @@ -284,37 +284,52 @@ Support has been added for the UEFI capsule update feature which
>  enables updating the U-Boot image using the UEFI firmware management
>  protocol (FMP). The capsules are not passed to the firmware through
>  the UpdateCapsule runtime service. Instead, capsule-on-disk
> -functionality is used for fetching the capsule from the EFI System
> -Partition (ESP) by placing the capsule file under the
> -\EFI\UpdateCapsule directory.
> -
> -The directory \EFI\UpdateCapsule is checked for capsules only within the
> -EFI system partition on the device specified in the active boot option
> -determined by reference to BootNext variable or BootOrder variable processing.
> -The active Boot Variable is the variable with highest priority BootNext or
> -within BootOrder that refers to a device found to be present. Boot variables
> -in BootOrder but referring to devices not present are ignored when determining
> -active boot variable.
> -Before starting a capsule update make sure your capsules are installed in the
> -correct ESP partition or set BootNext.
> +functionality is used for fetching capsules from the EFI System
> +Partition (ESP) by placing capsule files under the directory::
> +
> +    \EFI\UpdateCapsule

Can we use forward slashes please?

What is a backslash, even? DOS? Windows?

> +
> +The directory is checked for capsules only within the
> +EFI system partition on the device specified in the active boot option,
> +which is determined by BootXXXX variable in BootNext, or if not, the highest
> +priority one within BootOrder. Any BootXXXX variables referring to devices
> +not present are ignored when determining the active boot option.
> +
> +Please note that capsules will be applied in the alphabetic order of
> +capsule file names.
> +
> +Creating a capsule file
> +***********************
> +
> +A capsule file can be created by using tools/mkeficapsule.
> +To build this tool, enable::
> +
> +    CONFIG_TOOLS_MKEFICAPSULE=y
> +    CONFIG_TOOLS_LIBCRYPTO=y
> +
> +Run the following command::
> +
> +    $ mkeficapsule \
> +      --index 1 --instance 0 \
> +      [--fit <FIT image> | --raw <raw image>] \
> +      <capsule_file_name>
>
>  Performing the update
>  *********************
>
> -Since U-boot doesn't currently support SetVariable at runtime there's a Kconfig
> -option (CONFIG_EFI_IGNORE_OSINDICATIONS) to disable the OsIndications variable
> -check. If that option is enabled just copy your capsule to \EFI\UpdateCapsule.
> -
> -If that option is disabled, you'll need to set the OsIndications variable with::
> +Put capsule files under the directory mentioned above.
> +Then, following the UEFI specification, you'll need to set
> +the EFI_OS_INDICATIONS_FILE_CAPSULE_DELIVERY_SUPPORTED
> +bit in OsIndications variable with::
>
>      => setenv -e -nv -bs -rt -v OsIndications =0x04
>
> -Finally, the capsule update can be initiated either by rebooting the board,
> -which is the preferred method, or by issuing the following command::
> +Since U-boot doesn't currently support SetVariable at runtime, its value
> +won't be taken over across the reboot. If this is the case, you can skip
> +this feature check with the Kconfig option (CONFIG_EFI_IGNORE_OSINDICATIONS)
> +set.
>
> -    => efidebug capsule disk-update
> -
> -**The efidebug command is should only be used during debugging/development.**
> +Finally, the capsule update can be initiated by rebooting the board.
>
>  Enabling Capsule Authentication
>  *******************************
> @@ -324,82 +339,58 @@ be updated by verifying the capsule signature. The capsule signature
>  is computed and prepended to the capsule payload at the time of
>  capsule generation. This signature is then verified by using the
>  public key stored as part of the X509 certificate. This certificate is
> -in the form of an efi signature list (esl) file, which is embedded as
> -part of U-Boot.
> +in the form of an efi signature list (esl) file, which is embedded in
> +a device tree.
>
>  The capsule authentication feature can be enabled through the
>  following config, in addition to the configs listed above for capsule
>  update::
>
>      CONFIG_EFI_CAPSULE_AUTHENTICATE=y
> -    CONFIG_EFI_CAPSULE_KEY_PATH=<path to .esl cert>
>
>  The public and private keys used for the signing process are generated
> -and used by the steps highlighted below::
> +and used by the steps highlighted below.
>
> -    1. Install utility commands on your host
> -       * OPENSSL
> +1. Install utility commands on your host
> +       * openssl
>         * efitools
>
> -    2. Create signing keys and certificate files on your host
> +2. Create signing keys and certificate files on your host::
>
>          $ openssl req -x509 -sha256 -newkey rsa:2048 -subj /CN=CRT/ \
>              -keyout CRT.key -out CRT.crt -nodes -days 365
>          $ cert-to-efi-sig-list CRT.crt CRT.esl
>
> -        $ openssl x509 -in CRT.crt -out CRT.cer -outform DER
> -        $ openssl x509 -inform DER -in CRT.cer -outform PEM -out CRT.pub.pem
> -
> -        $ openssl pkcs12 -export -out CRT.pfx -inkey CRT.key -in CRT.crt
> -        $ openssl pkcs12 -in CRT.pfx -nodes -out CRT.pem
> -
> -The capsule file can be generated by using the GenerateCapsule.py
> -script in EDKII::
> -
> -    $ ./BaseTools/BinWrappers/PosixLike/GenerateCapsule -e -o \
> -      <capsule_file_name> --monotonic-count <val> --fw-version \
> -      <val> --lsv <val> --guid \
> -      e2bb9c06-70e9-4b14-97a3-5a7913176e3f --verbose \
> -      --update-image-index <val> --signer-private-cert \
> -      /path/to/CRT.pem --trusted-public-cert \
> -      /path/to/CRT.pub.pem --other-public-cert /path/to/CRT.pub.pem \
> -      <u-boot.bin>
> -
> -Place the capsule generated in the above step on the EFI System
> -Partition under the EFI/UpdateCapsule directory
> -
> -Testing on QEMU
> -***************
> +3. Run the following command to create and sign the capsule file::
>
> -Currently, support has been added on the QEMU ARM64 virt platform for
> -updating the U-Boot binary as a raw image when the platform is booted
> -in non-secure mode, i.e. with CONFIG_TFABOOT disabled. For this
> -configuration, the QEMU platform needs to be booted with
> -'secure=off'. The U-Boot binary placed on the first bank of the NOR
> -flash at offset 0x0. The U-Boot environment is placed on the second
> -NOR flash bank at offset 0x4000000.
> +    $ mkeficapsule --monotonic-count 1 \
> +      --private-key CRT.key \
> +      --certificate CRT.crt \
> +      --index 1 --instance 0 \
> +      [--fit <FIT image> | --raw <raw image>] \
> +      <capsule_file_name>
>
> -The capsule update feature is enabled with the following configuration
> -settings::
> +4. Insert the signature list into a device tree in the following format::
>
> -    CONFIG_MTD=y
> -    CONFIG_FLASH_CFI_MTD=y
> -    CONFIG_CMD_MTDPARTS=y
> -    CONFIG_CMD_DFU=y
> -    CONFIG_DFU_MTD=y
> -    CONFIG_PCI_INIT_R=y
> -    CONFIG_EFI_CAPSULE_ON_DISK=y
> -    CONFIG_EFI_CAPSULE_FIRMWARE_MANAGEMENT=y
> -    CONFIG_EFI_CAPSULE_FIRMWARE=y
> -    CONFIG_EFI_CAPSULE_FIRMWARE_RAW=y
> +        {
> +                signature {
> +                        capsule-key = [ <binary of signature list> ];
> +                }

Can you add this feature to binman? A new entry type that takes the
capsule key could do it. We need some way of handling this a bit
better.

> +                ...
> +        }
>
> -In addition, the following config needs to be disabled(QEMU ARM specific)::
> +   You can do this manually with::
>
> -    CONFIG_TFABOOT
> +    $ dtc -@ -I dts -O dtb -o signature.dtbo signature.dts
> +    $ fdtoverlay -i orig.dtb -o new.dtb -v signature.dtbo
>
> -The capsule file can be generated by using the tools/mkeficapsule::
> +   where signature.dts looks like::
>
> -    $ mkeficapsule --raw <u-boot.bin> --index 1 <capsule_file_name>
> +        &{/} {
> +                signature {
> +                        capsule-key = /incbin/("CRT.esl");
> +                };
> +        };

Ick. I think your tool should just support adding the signature.

>
>  Executing the boot manager
>  ~~~~~~~~~~~~~~~~~~~~~~~~~~
> --
> 2.33.0
>

Regards,
Simon


Regards,
SImon