Update the capsule update functionality related documentation to refect the additional definitions that need to be made per platform for supporting the capsule update feature.
Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org ---
Changes since V4:
* Change the description of the platform data based on the changes made in earlier patches
doc/develop/uefi/uefi.rst | 51 +++++++++++++++++++++++++++++++++++++-- 1 file changed, 49 insertions(+), 2 deletions(-)
diff --git a/doc/develop/uefi/uefi.rst b/doc/develop/uefi/uefi.rst index fe337c88bd..b766aecf67 100644 --- a/doc/develop/uefi/uefi.rst +++ b/doc/develop/uefi/uefi.rst @@ -312,8 +312,8 @@ Run the following command .. code-block:: console
$ mkeficapsule \ - --index 1 --instance 0 \ - [--fit <FIT image> | --raw <raw image>] \ + --index <index> --instance 0 \ + --guid <image GUID> \ <capsule_file_name>
Performing the update @@ -333,6 +333,53 @@ 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.
+A few values need to be defined in the board file for performing the +capsule update. These values are defined in the board file by +initialisation of a structure which provides information needed for +capsule updates. The following structures have been defined for +containing the image related information + +.. code-block:: c + + struct efi_fw_images { + efi_guid_t image_type_id; + u16 *fw_name; + u8 image_index; + }; + + struct efi_capsule_update_info { + const char *dfu_string; + struct efi_fw_images *images; + }; + + +A string is defined which is to be used for populating the +dfu_alt_info variable. This string is used by the function +set_dfu_alt_info. Instead of taking the variable from the environment, +the capsule update feature requires that the variable be set through +the function, since that is more robust. Allowing the user to change +the location of the firmware updates is not a very secure +practice. Getting this information from the firmware itself is more +secure, assuming the firmware has been verified by a previous stage +boot loader. + +The firmware images structure defines the GUID values, image index +values and the name of the images that are to be updated through +the capsule update feature. These values are to be defined as part of +an array. These GUID values would be used by the Firmware Management +Protocol(FMP) to populate the image descriptor array and also +displayed as part of the ESRT table. The image index values defined in +the array should be one greater than the dfu alt number that +corresponds to the firmware image. So, if the dfu alt number for an +image is 2, the value of image index in the fw_images array for that +image should be 3. The dfu alt number can be obtained by running the +following command:: + + dfu list + +When using the FMP for FIT images, the image index value needs to be +set to 1. + Finally, the capsule update can be initiated by rebooting the board.
Enabling Capsule Authentication