[PATCH 2/2] efi_loader: support FMP versioning for FWU multi bank update

Masahisa Kojima masahisa.kojima at linaro.org
Mon Dec 11 05:37:25 CET 2023


Hi Heinrich,

On Sun, 10 Dec 2023 at 00:09, Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
>
> On 11/14/23 10:25, Masahisa Kojima wrote:
> > Current FMP versioning uses the FMPStateXXXX UEFI variables
>
> Do you mean FmpState####?
>
> > that XXXX indicates image_index. When CONFIG_FWU_MULTI_BANK_UPDATE
> > is enabled, U-Boot instances installed in different banks
> > read the same FMPStateXXXX variable and it ends up with reading
> > wrong fw_version.
> >
> > This commit includes the bank_index in the FMPStateXXYY variable.
> > XX indicates a bank_index, YY indicates an image_index.
> > With this, it keeps backward compatibility for the case that
> > CONFIG_FWU_MULTI_BANK_UPDATE is not enabled, bank_index is
> > always 0 for this case.
> >
> > The bank index size is defined 4 bytes in FWU-PSA-A_DEN0118_1.0ALP3.pdf,
> > but 1-255 range is practically enough big. This commit adds the range
> > for FWU_NUM_BANKS since above XX(bank_index) has 1 byte.
>
> Who would need more than 16 banks (i.e. more than one digit)?
>
> What happens when the image number reaches 256 (or 4096 for 3 digits)?
> What happens with devices out in the field that already have reached
> image number 256?
>
> Why don't we store the fmp_state of all banks in the same FmpState####
> variable as an array? This should have a better chance of backwards
> compatibility.

Thanks. I will implement the next version with the array of versions
of each bank.

Regards,
Masahisa Kojima

>
> Best regards
>
> Heinrich
>
> >
> > Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
> > ---
> >   lib/efi_loader/efi_firmware.c | 63 ++++++++++++++++++++++++++---------
> >   lib/fwu_updates/Kconfig       |  1 +
> >   2 files changed, 48 insertions(+), 16 deletions(-)
> >
> > diff --git a/lib/efi_loader/efi_firmware.c b/lib/efi_loader/efi_firmware.c
> > index 9c1a273926..6d3620a649 100644
> > --- a/lib/efi_loader/efi_firmware.c
> > +++ b/lib/efi_loader/efi_firmware.c
> > @@ -205,13 +205,33 @@ static
> >   void efi_firmware_fill_version_info(struct efi_firmware_image_descriptor *image_info,
> >                                   struct efi_fw_image *fw_array)
> >   {
> > -     u16 varname[13]; /* u"FmpStateXXXX" */
> > +     int err;
> > +     u16 varname[13]; /* u"FmpStateXXYY" */
> >       efi_status_t ret;
> >       efi_uintn_t size;
> > +     uint active_bank = 0, var_index;
> >       struct fmp_state var_state = { 0 };
> >
> > +     efi_firmware_get_lsv_from_dtb(fw_array->image_index,
> > +                                   &fw_array->image_type_id,
> > +                                   &image_info->lowest_supported_image_version);
> > +
> > +     image_info->version_name = NULL; /* not supported */
> > +     image_info->last_attempt_version = 0;
> > +     image_info->last_attempt_status = LAST_ATTEMPT_STATUS_SUCCESS;
> > +
> > +     if (IS_ENABLED(CONFIG_FWU_MULTI_BANK_UPDATE)) {
> > +             err = fwu_get_active_index(&active_bank);
> > +             if (err) {
> > +                     log_debug("Unable to get active index\n");
> > +                     image_info->version = 0;
> > +                     return;
> > +             }
> > +     }
> > +
> > +     var_index = ((active_bank & 0xFF) << 8 | (fw_array->image_index & 0xFF));
> >       efi_create_indexed_name(varname, sizeof(varname), "FmpState",
> > -                             fw_array->image_index);
> > +                             var_index);
> >       size = sizeof(var_state);
> >       ret = efi_get_variable_int(varname, &fw_array->image_type_id,
> >                                  NULL, &size, &var_state, NULL);
> > @@ -219,14 +239,6 @@ void efi_firmware_fill_version_info(struct efi_firmware_image_descriptor *image_
> >               image_info->version = var_state.fw_version;
> >       else
> >               image_info->version = 0;
> > -
> > -     efi_firmware_get_lsv_from_dtb(fw_array->image_index,
> > -                                   &fw_array->image_type_id,
> > -                                   &image_info->lowest_supported_image_version);
> > -
> > -     image_info->version_name = NULL; /* not supported */
> > -     image_info->last_attempt_version = 0;
> > -     image_info->last_attempt_status = LAST_ATTEMPT_STATUS_SUCCESS;
> >   }
> >
> >   /**
> > @@ -353,15 +365,20 @@ efi_status_t efi_firmware_capsule_authenticate(const void **p_image,
> >    * @state:          Pointer to fmp state
> >    * @image_index:    image index
> >    *
> > - * Update the FmpStateXXXX variable with the firmware update state.
> > + * Update the FmpStateXXYY variable with the firmware update state.
> > + * XX is a bank index, YY is an image_index
> > + * When CONFIG_FWU_MULTI_BANK_UPDATE is not enabled, update_bank is always 0.
> >    *
> >    * Return:          status code
> >    */
> >   static
> >   efi_status_t efi_firmware_set_fmp_state_var(struct fmp_state *state, u8 image_index)
> >   {
> > -     u16 varname[13]; /* u"FmpStateXXXX" */
> > +     int err;
> > +     u16 varname[13]; /* u"FmpStateXXYY" */
> >       efi_status_t ret;
> > +     uint update_bank = 0;
> > +     unsigned int var_index;
> >       efi_guid_t *image_type_id;
> >       struct fmp_state var_state = { 0 };
> >
> > @@ -369,9 +386,15 @@ efi_status_t efi_firmware_set_fmp_state_var(struct fmp_state *state, u8 image_in
> >       if (!image_type_id)
> >               return EFI_INVALID_PARAMETER;
> >
> > -     efi_create_indexed_name(varname, sizeof(varname), "FmpState",
> > -                             image_index);
> > +     if (IS_ENABLED(CONFIG_FWU_MULTI_BANK_UPDATE)) {
> > +             err = fwu_plat_get_update_index(&update_bank);
> > +             if (err)
> > +                     return EFI_INVALID_PARAMETER;
> > +     }
> >
> > +     var_index = ((update_bank & 0xFF) << 8 | (image_index & 0xFF));
> > +     efi_create_indexed_name(varname, sizeof(varname), "FmpState",
> > +                             var_index);
> >       /*
> >        * Only the fw_version is set here.
> >        * lowest_supported_version in FmpState variable is ignored since
> > @@ -563,7 +586,11 @@ efi_status_t EFIAPI efi_firmware_fit_set_image(
> >       if (fit_update(image))
> >               return EFI_EXIT(EFI_DEVICE_ERROR);
> >
> > -     efi_firmware_set_fmp_state_var(&state, image_index);
> > +     status = efi_firmware_set_fmp_state_var(&state, image_index);
> > +     if (status != EFI_SUCCESS) {
> > +             log_err("Set FmpState variable failed\n");
> > +             return EFI_EXIT(status);
> > +     }
> >
> >       return EFI_EXIT(EFI_SUCCESS);
> >   }
> > @@ -643,7 +670,11 @@ efi_status_t EFIAPI efi_firmware_raw_set_image(
> >                            NULL, NULL))
> >               return EFI_EXIT(EFI_DEVICE_ERROR);
> >
> > -     efi_firmware_set_fmp_state_var(&state, original_image_index);
> > +     status = efi_firmware_set_fmp_state_var(&state, original_image_index);
> > +     if (status != EFI_SUCCESS) {
> > +             log_err("Set FmpState variable failed\n");
> > +             return EFI_EXIT(status);
> > +     }
> >
> >       return EFI_EXIT(EFI_SUCCESS);
> >   }
> > diff --git a/lib/fwu_updates/Kconfig b/lib/fwu_updates/Kconfig
> > index d35247d0e5..eb42f25fc0 100644
> > --- a/lib/fwu_updates/Kconfig
> > +++ b/lib/fwu_updates/Kconfig
> > @@ -14,6 +14,7 @@ if FWU_MULTI_BANK_UPDATE
> >
> >   config FWU_NUM_BANKS
> >       int "Number of Banks defined by the platform"
> > +     range 1 255
> >       help
> >         Define the number of banks of firmware images on a platform
> >
>


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