[PATCH v9 04/11] efi_loader: capsule: support firmware update

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

Sughosh,

On Sat, Nov 21, 2020 at 11:32:43PM +0530, Sughosh Ganu wrote:
> hi Takahiro,
> 
> On Tue, 17 Nov 2020 at 05:58, AKASHI Takahiro <takahiro.akashi@linaro.org>
> wrote:
> 
> > A capsule tagged with the guid, EFI_FIRMWARE_MANAGEMENT_CAPSULE_ID_GUID,
> > is handled as a firmware update object.
> > What efi_update_capsule() basically does is to load any firmware management
> > protocol (or fmp) drivers contained in a capsule, find out an appropriate
> > fmp driver and then invoke its set_image() interface against each binary
> > in a capsule.
> > In this commit, however, loading drivers is not supported.
> >
> > The result of applying a capsule is set to be stored in "CapsuleXXXX"
> > variable, but its implementation is deferred to a fmp driver.
> >
> > Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> > ---
> >  include/efi_api.h            | 129 +++++++++++++++++++
> >  include/efi_loader.h         |   2 +
> >  lib/efi_loader/Kconfig       |   8 ++
> >  lib/efi_loader/efi_capsule.c | 238 ++++++++++++++++++++++++++++++++++-
> >  lib/efi_loader/efi_setup.c   |   4 +
> >  5 files changed, 380 insertions(+), 1 deletion(-)
> >
> > diff --git a/include/efi_api.h b/include/efi_api.h
> > index 7a2a087c60ed..966bc6e590bf 100644
> > --- a/include/efi_api.h
> > +++ b/include/efi_api.h
> > @@ -217,6 +217,9 @@ enum efi_reset_type {
> >  #define CAPSULE_FLAGS_POPULATE_SYSTEM_TABLE    0x00020000
> >  #define CAPSULE_FLAGS_INITIATE_RESET           0x00040000
> >
> > +#define CAPSULE_SUPPORT_AUTHENTICATION         0x0000000000000001
> > +#define CAPSULE_SUPPORT_DEPENDENCY             0x0000000000000002
> > +
> >  #define EFI_CAPSULE_REPORT_GUID \
> >         EFI_GUID(0x39b68c46, 0xf7fb, 0x441b, 0xb6, 0xec, \
> >                  0x16, 0xb0, 0xf6, 0x98, 0x21, 0xf3)
> > @@ -225,6 +228,10 @@ enum efi_reset_type {
> >         EFI_GUID(0xde9f0ec, 0x88b6, 0x428f, 0x97, 0x7a, \
> >                  0x25, 0x8f, 0x1d, 0xe, 0x5e, 0x72)
> >
> > +#define EFI_FIRMWARE_MANAGEMENT_CAPSULE_ID_GUID \
> > +       EFI_GUID(0x6dcbd5ed, 0xe82d, 0x4c44, 0xbd, 0xa1, \
> > +                0x71, 0x94, 0x19, 0x9a, 0xd9, 0x2a)
> > +
> >  struct efi_capsule_header {
> >         efi_guid_t capsule_guid;
> >         u32 header_size;
> > @@ -253,6 +260,33 @@ struct efi_memory_range_capsule {
> >         struct efi_memory_range memory_ranges[];
> >  } __packed;
> >
> > +struct efi_firmware_management_capsule_header {
> > +       u32 version;
> > +       u16 embedded_driver_count;
> > +       u16 payload_item_count;
> > +       u64 item_offset_list[];
> > +} __packed;
> > +
> > +struct efi_firmware_management_capsule_image_header {
> > +       u32 version;
> > +       efi_guid_t update_image_type_id;
> > +       u8 update_image_index;
> > +       u8 reserved[3];
> > +       u32 update_image_size;
> > +       u32 update_vendor_code_size;
> > +       u64 update_hardware_instance;
> > +       u64 image_capsule_support;
> > +} __packed;
> > +
> > +struct efi_capsule_result_variable_fmp {
> > +       u16 version;
> > +       u8 payload_index;
> > +       u8 update_image_index;
> > +       efi_guid_t update_image_type_id;
> > +       // u16 capsule_file_name[];
> > +       // u16 capsule_target[];
> > +} __packed;
> > +
> >
> 
> <snip>
> 
> 
> > +/**
> > + * efi_capsule_update_firmware - update firmware from capsule
> > + * @capsule_data:      Capsule
> > + *
> > + * Update firmware, using a capsule, @capsule_data. Loading any FMP
> > + * drivers embedded in a capsule is not supported.
> > + *
> > + * Return:             status code
> > + */
> > +static efi_status_t efi_capsule_update_firmware(
> > +               struct efi_capsule_header *capsule_data)
> > +{
> > +       struct efi_firmware_management_capsule_header *capsule;
> > +       struct efi_firmware_management_capsule_image_header *image;
> > +       size_t capsule_size;
> > +       void *image_binary, *vendor_code;
> > +       efi_handle_t *handles;
> > +       efi_uintn_t no_handles;
> > +       int item;
> > +       struct efi_firmware_management_protocol *fmp;
> > +       u16 *abort_reason;
> > +       efi_status_t ret = EFI_SUCCESS;
> > +
> > +       /* sanity check */
> > +       if (capsule_data->header_size < sizeof(*capsule) ||
> > +           capsule_data->header_size >= capsule_data->capsule_image_size)
> > +               return EFI_INVALID_PARAMETER;
> > +
> > +       capsule = (void *)capsule_data + capsule_data->header_size;
> > +       capsule_size = capsule_data->capsule_image_size
> > +                       - capsule_data->header_size;
> > +
> > +       if (capsule->version != 0x00000001)
> > +               return EFI_INVALID_PARAMETER;
> > +
> > +       /* Drivers */
> > +       /* TODO: support loading drivers */
> > +
> > +       handles = NULL;
> > +       ret = EFI_CALL(efi_locate_handle_buffer(
> > +                       BY_PROTOCOL,
> > +                       &efi_guid_firmware_management_protocol,
> > +                       NULL, &no_handles, (efi_handle_t **)&handles));
> > +       if (ret != EFI_SUCCESS)
> > +               return EFI_UNSUPPORTED;
> > +
> > +       /* Payload */
> > +       for (item = capsule->embedded_driver_count;
> > +            item < capsule->embedded_driver_count
> > +                   + capsule->payload_item_count; item++) {
> > +               /* sanity check */
> > +               if ((capsule->item_offset_list[item] + sizeof(*image)
> > +                                >= capsule_size)) {
> > +                       printf("EFI: A capsule has not enough size of
> > data\n");
> > +                       ret = EFI_INVALID_PARAMETER;
> > +                       goto out;
> > +               }
> > +
> > +               image = (void *)capsule + capsule->item_offset_list[item];
> > +
> > +               if (image->version != 0x00000001 &&
> > +                   image->version != 0x00000002 &&
> > +                   image->version != 0x00000003) {
> > +                       ret = EFI_INVALID_PARAMETER;
> > +                       goto out;
> > +               }
> > +
> > +               /* find a device for update firmware */
> > +               /* TODO: should we pass index as well, or nothing but
> > type? */
> > +               fmp = efi_fmp_find(&image->update_image_type_id,
> > +                                  image->version == 0x1 ? 0 :
> > +                                       image->update_hardware_instance,
> > +                                  handles, no_handles);
> > +               if (!fmp) {
> > +                       printf("EFI Capsule: driver not found for firmware
> > type: %pUl, hardware instance: %lld\n",
> > +                              &image->update_image_type_id,
> > +                              image->version == 0x1 ? 0 :
> > +                                       image->update_hardware_instance);
> > +                       ret = EFI_UNSUPPORTED;
> > +                       goto out;
> > +               }
> > +
> > +               /* do it */
> > +               image_binary = (void *)image + sizeof(*image);
> >
> 
> Sorry for not having spotted this earlier. But since we are supporting the
> first three versions of the  struct
> efi_firmware_management_capsule_image_header, the above logic needs to be
> changed to accomodate versions 1 and 2. So in case of a version 1
> structure, the fields update_hardware_instance and image_capsule_support
> need to be discarded. Similarly for a version 2 structure, the
> image_capsule_support field needs to be discarded while calculating the
> image_binary pointer.

Thank you for catching this issue, you're right.

Given, however, that the firmware update is quite firmware-specific
and that we don't have any "backward compatibility" requirement,
it would be better to simply drop the support for previous versions
and to support the current/latest one, in this case, 3.

We have a similar issue on 'struct efi_firmware_image_descriptor'.
I hope that imposing a version check/restriction won't bring any
inconvenience to anybody.

-Takahiro Akashi

> -sughosh