Re: [PATCH v4 05/11] EFI: FMP: Add provision to update image's ImageTypeId in image descriptor

[AKASHI Takahiro <takahiro.akashi@linaro.org>]

Sughosh,

On Thu, Feb 10, 2022 at 03:40:00PM +0530, Sughosh Ganu wrote:
> On Thu, 10 Feb 2022 at 13:28, AKASHI Takahiro
> <takahiro.akashi@linaro.org> wrote:
> >
> > On Thu, Feb 10, 2022 at 12:48:13PM +0530, Sughosh Ganu wrote:
> > > hi Takahiro,
> > >
> > > On Thu, 10 Feb 2022 at 08:18, AKASHI Takahiro
> > > <takahiro.akashi@linaro.org> wrote:
> > > >
> > > > Hi Sughosh,
> > > >
> > > > On Mon, Feb 07, 2022 at 11:49:55PM +0530, Sughosh Ganu wrote:
> > > > > The FWU Multi Banks Update feature allows updating different types of
> > > > > updatable firmware images on the platform. These image types are
> > > > > identified using the ImageTypeId GUID value. Add support in the
> > > > > GetImageInfo function of the FMP protocol to get the GUID values for
> > > > > the individual images and populate these in the image descriptor for
> > > > > the corresponding images.
> > > >
> > > > After re-thinking of your approach here, I would have to say NAK.
> > > >
> > > > You use ImageTypeId to identify a particular firmware object.
> > > > (By "object," I mean one of firmware instances represented by "dfu_alto_info".
> > > > Please don't confuse it with the binary blob embedded in a capsule file.)
> > > > But ImageTypeId is not for that purpose, at least, as my intention
> > > > in initially implementing capsule framework and FMP drivers.
> > > >
> > > > 1) ImageTypeId is used to uniquely identify a corresponding FMP driver,
> > > >    either FIT FMP driver or Raw FMP driver.
> > >
> > > I believe the identification of an FMP protocol should be done by the
> > > FMP GUID,
> >
> > What does FMP GUID stand for?
> 
> EFI_FIRMWARE_MANAGEMENT_PROTOCOL_GUID, defined in include/efi_api.h.
> What I mean is that even when installing the FMP protocol, the call to
> efi_install_multiple_protocol_interfaces takes the above FMP GUID as
> an argument -- nowhere is the ImageTypeId considered when installing
> the protocol.

Okay.

> >
> > > which is what is done in efi_fmp_find. The ImageTypeId is
> > > nowhere involved in this identification.
> >
> > Please take a look at efi_capsule_update_firmware() carefully.
> > efi_find_fmp() is called with the image's update_image_type_id
> > which is to be set to EFI_FIRMWARE_IMAGE_TYPE_UBOOT_FIT_GUID or
> > EFI_FIRMWARE_IMAGE_TYPE_UBOOT_RAW_GUID by mkeficapsule
> > (see create_fwbin()).
> 
> I think you are thinking from the point of view of the '--guid' value
> that is being passed to the capsule generation tool. But the thing is
> that it is the current design(or limitation) of the tool that it takes
> only a single guid parameter. So the mkeficapsule tool currently can
> generate only a single payload capsule.

That is exactly what I intended to do here.
We have only one FMP driver (either FIT or RAW) which is based on
U-Boot's DFU framework and we need only one payload since, for
multiple objects of firmware, we can use FIT format as a payload.
That is what FIT is aimed for.
Or you can use multiple RAW capsule files with different indexes
("--index" exists for this purpose).

> Please check the
> GenerateCapsule script in EDK2. In case of a multi payload based
> capsule, individual parameters like the UpdateImageTypeId are passed
> through the json file, where each of the UpdateImageTypeId has a
> different value per payload.
> 
> >
> > > > 2) Each firmware object handled by a given FMP driver can further be
> > > >    identified by ImageIndex.
> > > >
> > > > My implementation of efi_fmp_find() does (1) and Raw FMP driver does
> > > > (2) in efi_firmware_raw_set_image() which takes "image_index" as
> > > > a parameter.
> > > >
> > > > Using ImageTypeId as an identifier is simply wrong in my opinion and
> > > > doesn't meet the UEFI specification.
> > >
> > > So, as per what you are stating, all payloads under a given
> > > EFI_FIRMWARE_MANAGEMENT_CAPSULE_HEADER should have the same
> > > ImageTypeId, either EFI_FIRMWARE_IMAGE_TYPE_UBOOT_FIT_GUID or
> > > EFI_FIRMWARE_IMAGE_TYPE_UBOOT_RAW_GUID. Same applies for all images in
> > > the EFI_FIRMWARE_IMAGE_DESCRIPTOR. Because, without one of the two
> > > values, > the check in efi_fmp_find to compare the UpdateImageTypeId
> > > with the ImageTypeId retrieved from the image descriptor would simply
> > > fail.
> >
> > I don't follow your point.
> > Please elaborate a bit more.
> 
> The current implementation of GetImageInfo, passes either of
> EFI_FIRMWARE_IMAGE_TYPE_UBOOT_FIT_GUID or
> EFI_FIRMWARE_IMAGE_TYPE_UBOOT_RAW_GUID for all the images of the image
> descriptor array. So, in case the capsule is generated with a '--guid'
> value which is different from these two values, the check in
> efi_fmp_find on line 204 will fail.

That is an expected behavior, isn't it?
If you want to use a different FMP driver (with another GUID),
you naturally need to add your own FMP driver.


> This means that unless the --guid
> value passed to the capsule generation is either of u-boot FIT or
> u-boot raw, the current FMP protocol for raw devices cannot be used.
> Why do we need that restriction. It should be possible to use the raw
> FMP protocol for any other type of image types as well.
> 
> 
> >
> > > I think this interpretation of the UEFI spec is incorrect, since the
> > > spec states that the ImageTypeId and the UpdateImageTypeId are fields
> > > used to identify the firmware component targeted for the update. If
> > > all values in the image descriptor array and the UpdateImageTypeId are
> > > the same, why have this field in the first place for individual
> > > images.
> >
> > As I said, ImageIndex is for that purpose.
> 
> Yes, that is one possible way in the scenario where the ImageIndex is
> determined at the capsule generation time. But, for the A/B update
> scenario, we do not know the ImageIndex at build time

"Build time" of what?
I think that users should know how "dfu_alt_info" is defined
(in other words, where the firmware be located on the target system)
when capsule files are created.

-Takahiro Akashi


> -- this is
> determined only at runtime, and is based on the bank to which the
> image is to be updated. Which is why I am finding out the alt_num at
> runtime in case the FWU Multi Bank feature is enabled. Like I said
> above, I do not see a reason why the current FMP protocols should be
> restricted to only the u-boot FIT and u-boot raw image types. It is
> being extended, without affecting the default non FWU behaviour.
> 
> -sughosh
> 
> >
> > -Takahiro Akashi
> >
> > >
> > > -sughosh
> > >
> > > >
> > > > -Takahiro Akashi
> > > >
> > > >
> > > > > Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> > > > > ---
> > > > >
> > > > > Changes since V3:
> > > > > * Define a weak function fill_image_type_guid_array for populating the
> > > > >   image descriptor array with u-boot's raw and fit image GUIDs
> > > > >
> > > > >  include/efi_loader.h          |  2 +
> > > > >  lib/efi_loader/efi_firmware.c | 71 +++++++++++++++++++++++++++++++----
> > > > >  2 files changed, 66 insertions(+), 7 deletions(-)
> > > > >
> > > > > diff --git a/include/efi_loader.h b/include/efi_loader.h
> > > > > index f4860e87fc..ae60de0be5 100644
> > > > > --- a/include/efi_loader.h
> > > > > +++ b/include/efi_loader.h
> > > > > @@ -992,4 +992,6 @@ efi_status_t efi_esrt_populate(void);
> > > > >  efi_status_t efi_load_capsule_drivers(void);
> > > > >
> > > > >  efi_status_t platform_get_eventlog(struct udevice *dev, u64 *addr, u32 *sz);
> > > > > +efi_status_t fill_image_type_guid_array(const efi_guid_t *default_guid,
> > > > > +                                     efi_guid_t **part_guid_arr);
> > > > >  #endif /* _EFI_LOADER_H */
> > > > > diff --git a/lib/efi_loader/efi_firmware.c b/lib/efi_loader/efi_firmware.c
> > > > > index a1b88dbfc2..5642be9f9a 100644
> > > > > --- a/lib/efi_loader/efi_firmware.c
> > > > > +++ b/lib/efi_loader/efi_firmware.c
> > > > > @@ -96,6 +96,46 @@ efi_status_t EFIAPI efi_firmware_set_package_info_unsupported(
> > > > >       return EFI_EXIT(EFI_UNSUPPORTED);
> > > > >  }
> > > > >
> > > > > +efi_status_t __weak fill_image_type_guid_array(const efi_guid_t *guid,
> > > > > +                                            efi_guid_t **part_guid_arr)
> > > > > +{
> > > > > +     int i;
> > > > > +     int dfu_num = 0;
> > > > > +     efi_guid_t *guid_arr;
> > > > > +     struct dfu_entity *dfu;
> > > > > +     efi_status_t ret = EFI_SUCCESS;
> > > > > +
> > > > > +     dfu_init_env_entities(NULL, NULL);
> > > > > +
> > > > > +     dfu_num = 0;
> > > > > +     list_for_each_entry(dfu, &dfu_list, list) {
> > > > > +             dfu_num++;
> > > > > +     }
> > > > > +
> > > > > +     if (!dfu_num) {
> > > > > +             log_warning("Probably dfu_alt_info not defined\n");
> > > > > +             ret = EFI_NOT_READY;
> > > > > +             goto out;
> > > > > +     }
> > > > > +
> > > > > +     *part_guid_arr = malloc(sizeof(efi_guid_t) * dfu_num);
> > > > > +     if (!*part_guid_arr) {
> > > > > +             ret = EFI_OUT_OF_RESOURCES;
> > > > > +             goto out;
> > > > > +     }
> > > > > +
> > > > > +     guid_arr = *part_guid_arr;
> > > > > +     for (i = 0; i < dfu_num; i++) {
> > > > > +             guidcpy(guid_arr, guid);
> > > > > +             ++guid_arr;
> > > > > +     }
> > > > > +
> > > > > +out:
> > > > > +     dfu_free_entities();
> > > > > +
> > > > > +     return ret;
> > > > > +}
> > > > > +
> > > > >  /**
> > > > >   * efi_get_dfu_info - return information about the current firmware image
> > > > >   * @this:                    Protocol instance
> > > > > @@ -104,9 +144,9 @@ efi_status_t EFIAPI efi_firmware_set_package_info_unsupported(
> > > > >   * @descriptor_version:              Pointer to version number
> > > > >   * @descriptor_count:                Pointer to number of descriptors
> > > > >   * @descriptor_size:         Pointer to descriptor size
> > > > > - * package_version:          Package version
> > > > > - * package_version_name:     Package version's name
> > > > > - * image_type:                       Image type GUID
> > > > > + * @package_version:         Package version
> > > > > + * @package_version_name:    Package version's name
> > > > > + * @guid_array:                      Image type GUID array
> > > > >   *
> > > > >   * Return information bout the current firmware image in @image_info.
> > > > >   * @image_info will consist of a number of descriptors.
> > > > > @@ -122,7 +162,7 @@ static efi_status_t efi_get_dfu_info(
> > > > >       efi_uintn_t *descriptor_size,
> > > > >       u32 *package_version,
> > > > >       u16 **package_version_name,
> > > > > -     const efi_guid_t *image_type)
> > > > > +     const efi_guid_t *guid_array)
> > > > >  {
> > > > >       struct dfu_entity *dfu;
> > > > >       size_t names_len, total_size;
> > > > > @@ -172,7 +212,7 @@ static efi_status_t efi_get_dfu_info(
> > > > >       next = name;
> > > > >       list_for_each_entry(dfu, &dfu_list, list) {
> > > > >               image_info[i].image_index = dfu->alt + 1;
> > > > > -             image_info[i].image_type_id = *image_type;
> > > > > +             image_info[i].image_type_id = guid_array[i];
> > > > >               image_info[i].image_id = dfu->alt;
> > > > >
> > > > >               /* copy the DFU entity name */
> > > > > @@ -250,6 +290,7 @@ efi_status_t EFIAPI efi_firmware_fit_get_image_info(
> > > > >       u16 **package_version_name)
> > > > >  {
> > > > >       efi_status_t ret;
> > > > > +     efi_guid_t *part_guid_arr = NULL;
> > > > >
> > > > >       EFI_ENTRY("%p %p %p %p %p %p %p %p\n", this,
> > > > >                 image_info_size, image_info,
> > > > > @@ -264,12 +305,19 @@ efi_status_t EFIAPI efi_firmware_fit_get_image_info(
> > > > >            !descriptor_size || !package_version || !package_version_name))
> > > > >               return EFI_EXIT(EFI_INVALID_PARAMETER);
> > > > >
> > > > > +     ret = fill_image_type_guid_array(&efi_firmware_image_type_uboot_fit,
> > > > > +                                      &part_guid_arr);
> > > > > +     if (ret != EFI_SUCCESS)
> > > > > +             goto out;
> > > > > +
> > > > >       ret = efi_get_dfu_info(image_info_size, image_info,
> > > > >                              descriptor_version, descriptor_count,
> > > > >                              descriptor_size,
> > > > >                              package_version, package_version_name,
> > > > > -                            &efi_firmware_image_type_uboot_fit);
> > > > > +                            part_guid_arr);
> > > > >
> > > > > +out:
> > > > > +     free(part_guid_arr);
> > > > >       return EFI_EXIT(ret);
> > > > >  }
> > > > >
> > > > > @@ -359,6 +407,7 @@ efi_status_t EFIAPI efi_firmware_raw_get_image_info(
> > > > >       u16 **package_version_name)
> > > > >  {
> > > > >       efi_status_t ret = EFI_SUCCESS;
> > > > > +     efi_guid_t *part_guid_arr = NULL;
> > > > >
> > > > >       EFI_ENTRY("%p %p %p %p %p %p %p %p\n", this,
> > > > >                 image_info_size, image_info,
> > > > > @@ -373,12 +422,20 @@ efi_status_t EFIAPI efi_firmware_raw_get_image_info(
> > > > >            !descriptor_size || !package_version || !package_version_name))
> > > > >               return EFI_EXIT(EFI_INVALID_PARAMETER);
> > > > >
> > > > > +     ret = fill_image_type_guid_array(
> > > > > +             &efi_firmware_image_type_uboot_raw,
> > > > > +             &part_guid_arr);
> > > > > +     if (ret != EFI_SUCCESS)
> > > > > +             goto out;
> > > > > +
> > > > >       ret = efi_get_dfu_info(image_info_size, image_info,
> > > > >                              descriptor_version, descriptor_count,
> > > > >                              descriptor_size,
> > > > >                              package_version, package_version_name,
> > > > > -                            &efi_firmware_image_type_uboot_raw);
> > > > > +                            part_guid_arr);
> > > > >
> > > > > +out:
> > > > > +     free(part_guid_arr);
> > > > >       return EFI_EXIT(ret);
> > > > >  }
> > > > >
> > > > > --
> > > > > 2.17.1
> > > > >