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 V6: * Add example for the struct efi_fw_image array and struct efi_capsule_update_info as suggested by Takahiro
doc/develop/uefi/uefi.rst | 98 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 96 insertions(+), 2 deletions(-)
diff --git a/doc/develop/uefi/uefi.rst b/doc/develop/uefi/uefi.rst index fe337c88bd..1aea04a4e8 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 @@ -333,9 +333,102 @@ 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_image *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.
+An example of setting the values in the struct efi_fw_image and +struct efi_capsule_update_info is shown below + +.. code-block:: c + + struct efi_fw_image fw_images[] = { + { + .image_type_id = DEVELOPERBOX_UBOOT_IMAGE_GUID, + .fw_name = u"DEVELOPERBOX-UBOOT", + .image_index = 1, + }, + { + .image_type_id = DEVELOPERBOX_FIP_IMAGE_GUID, + .fw_name = u"DEVELOPERBOX-FIP", + .image_index = 2, + }, + { + .image_type_id = DEVELOPERBOX_OPTEE_IMAGE_GUID, + .fw_name = u"DEVELOPERBOX-OPTEE", + .image_index = 3, + }, + }; + + struct efi_capsule_update_info update_info = { + .dfu_string = "mtd nor1=u-boot.bin raw 200000 100000;" + "fip.bin raw 180000 78000;" + "optee.bin raw 500000 100000", + .images = fw_images, + }; + +The platform will define a fw_images array which contains information +of all the firmware images that are to be updated through capsule +update mechanism. The dfu_string is the string that is to be set as +dfu_alt_info. In the example above, the image index to be set for +u-boot.bin binary is 0x1, for fip.bin is 0x2 and for optee.bin is 0x3. + +As an example, for generating the capsule for the optee.bin image, the +following command can be issued + +.. code-block:: bash + + $ ./tools/mkeficapsule \ + --index 0x3 --instance 0 \ + --guid c1b629f1-ce0e-4894-82bf-f0a38387e630 \ + optee.bin optee.capsule + + Enabling Capsule Authentication *******************************