Re: [RFC PATCH v2 2/8] FWU: Add FWU metadata access functions for GPT partitioned block devices

Hi Sughosh,

2021年12月19日(日) 16:06 Sughosh Ganu sughosh.ganu@linaro.org:

+static int gpt_get_image_alt_num(struct blk_desc *desc,

•                            efi_guid_t image_type_id,
  

•                            u32 update_bank, int *alt_no)
  

+{

•   int ret, i;
  

•   u32 part;
  

•   struct fwu_mdata *mdata;
  

•   struct fwu_image_entry *img_entry;
  

•   struct fwu_image_bank_info *img_bank_info;
  

•   struct disk_partition info;
  

•   efi_guid_t unique_part_guid;
  

•   efi_guid_t image_guid = NULL_GUID;
  

•   ret = gpt_get_mdata(&mdata);
  

•   if (ret < 0) {
  

•           log_err("Unable to read valid FWU metadata\n");
  

•           goto out;
  

•   }
  

•   /*
  

•    * The FWU metadata has been read. Now get the image_uuid for the
  

•    * image with the update_bank.
  

•    */
  

•   for (i = 0; i < CONFIG_FWU_NUM_IMAGES_PER_BANK; i++) {
  

•           if (!guidcmp(&image_type_id,
  

•                        &mdata->img_entry[i].image_type_uuid)) {
  

•                   img_entry = &mdata->img_entry[i];
  

•                   img_bank_info = &img_entry->img_bank_info[update_bank];
  

•                   guidcpy(&image_guid, &img_bank_info->image_uuid);
  

•                   break;
  

•           }
  

•   }
  

•   /*
  

•    * Now read the GPT Partition Table Entries to find a matching
  

•    * partition with UniquePartitionGuid value. We need to iterate
  

•    * through all the GPT partitions since they might be in any
  

•    * order
  

•    */
  

•   for (i = 1; i < MAX_SEARCH_PARTITIONS; i++) {
  

•           if (part_get_info(desc, i, &info))
  

•                   continue;
  

•           uuid_str_to_bin(info.uuid, unique_part_guid.b,
  

•                           UUID_STR_FORMAT_GUID);
  

•           if (!guidcmp(&unique_part_guid, &image_guid)) {
  

•                   /* Found the partition */
  

•                   part = i;
  

•                   *alt_no = fwu_plat_get_alt_num(desc->devnum, &part);
  

This is still GPT depending interface. In my use case (no GPT but raw SPI flash) I don't have devnum. Moreover, this one is used only from the fwu_mdata_gpt_blk.c. Please ensure (and comment) that this is only for GPT user.

•                   if (*alt_no != -1)
  

•                           log_info("alt_num %d for partition %pUl\n",
  

•                                     *alt_no, &image_guid);
  

•                   ret = 0;
  

•                   break;
  

•           }
  

•   }
  

•   if (*alt_no == -1) {
  

•           log_err("alt_num not found for partition with GUID %pUl\n",
  

•                   &image_guid);
  

•           ret = -EINVAL;
  

•   }
  

•   if (i == MAX_SEARCH_PARTITIONS) {
  

•           log_err("Partition with the image guid not found\n");
  

•           ret = -EINVAL;
  

•   }
  

+out:

•   free(mdata);
  

•   return ret;
  

+}

+int fwu_gpt_update_active_index(u32 active_idx) +{

•   int ret;
  

•   void *buf;
  

•   struct fwu_mdata *mdata;
  

•   if (active_idx > CONFIG_FWU_NUM_BANKS) {
  

•           printf("Active index value to be updated is incorrect\n");
  

•           return -1;
  

•   }
  

•   ret = gpt_get_mdata(&mdata);
  

•   if (ret < 0) {
  

•           log_err("Unable to get valid FWU metadata\n");
  

•           goto out;
  

•   }
  

•   /*
  

•    * Update the active index and previous_active_index fields
  

•    * in the FWU metadata
  

•    */
  

•   mdata->previous_active_index = mdata->active_index;
  

•   mdata->active_index = active_idx;
  

•   /*
  

•    * Calculate the crc32 for the updated FWU metadata
  

•    * and put the updated value in the FWU metadata crc32
  

•    * field
  

•    */
  

•   buf = &mdata->version;
  

•   mdata->crc32 = crc32(0, buf, sizeof(*mdata) - sizeof(u32));
  

•   /*
  

•    * Now write this updated FWU metadata to both the
  

•    * FWU metadata partitions
  

•    */
  

•   ret = gpt_update_mdata(mdata);
  

•   if (ret < 0) {
  

•           log_err("Failed to update FWU metadata partitions\n");
  

•           ret = -EIO;
  

•   }
  

+out:

•   free(mdata);
  

•   return ret;
  

+}

+int fwu_gpt_get_image_alt_num(efi_guid_t image_type_id, u32 update_bank,

•                         int *alt_no)
  

+{

•   int ret;
  

•   struct blk_desc *desc;
  

•   ret = fwu_plat_get_blk_desc(&desc);
  

•   if (ret < 0) {
  

•           log_err("Block device not found\n");
  

•           return -ENODEV;
  

•   }
  

•   return gpt_get_image_alt_num(desc, image_type_id, update_bank, alt_no);
  

+}

+int fwu_gpt_mdata_check(void) +{

•   /*
  

•    * Check if both the copies of the FWU metadata are
  

•    * valid. If one has gone bad, restore it from the
  

•    * other good copy.
  

•    */
  

•   return gpt_check_mdata_validity();
  

+}

+int fwu_gpt_get_mdata(struct fwu_mdata **mdata) +{

•   return gpt_get_mdata(mdata);
  

+}

+int fwu_gpt_revert_boot_index(void) +{

•   int ret;
  

•   void *buf;
  

•   u32 cur_active_index;
  

•   struct fwu_mdata *mdata;
  

•   ret = gpt_get_mdata(&mdata);
  

•   if (ret < 0) {
  

•           log_err("Unable to get valid FWU metadata\n");
  

•           goto out;
  

•   }
  

•   /*
  

•    * Swap the active index and previous_active_index fields
  

•    * in the FWU metadata
  

•    */
  

•   cur_active_index = mdata->active_index;
  

•   mdata->active_index = mdata->previous_active_index;
  

•   mdata->previous_active_index = cur_active_index;
  

•   /*
  

•    * Calculate the crc32 for the updated FWU metadata
  

•    * and put the updated value in the FWU metadata crc32
  

•    * field
  

•    */
  

•   buf = &mdata->version;
  

•   mdata->crc32 = crc32(0, buf, sizeof(*mdata) - sizeof(u32));
  

•   /*
  

•    * Now write this updated FWU metadata to both the
  

•    * FWU metadata partitions
  

•    */
  

•   ret = gpt_update_mdata(mdata);
  

If we have the fwu_update_mdata(), you can make this fwu_gpt_revert_boot_index() and above fwu_gpt_update_boot_index() platform agnostic. (in that case "gpt" must be removed), because there is no dependency to GPT.

•   if (ret < 0) {
  

•           log_err("Failed to update FWU metadata partitions\n");
  

•           ret = -EIO;
  

•   }
  

+out:

•   free(mdata);
  

•   return ret;
  

+}

+static int fwu_gpt_set_clear_image_accept(efi_guid_t *img_type_id,

•                                     u32 bank, u8 action)
  

+{

•   void *buf;
  

•   int ret, i;
  

•   u32 nimages;
  

•   struct fwu_mdata *mdata;
  

•   struct fwu_image_entry *img_entry;
  

•   struct fwu_image_bank_info *img_bank_info;
  

•   ret = gpt_get_mdata(&mdata);
  

•   if (ret < 0) {
  

•           log_err("Unable to get valid FWU metadata\n");
  

•           goto out;
  

•   }
  

•   if (action == IMAGE_ACCEPT_SET)
  

•           bank = mdata->active_index;
  

•   nimages = CONFIG_FWU_NUM_IMAGES_PER_BANK;
  

•   img_entry = &mdata->img_entry[0];
  

•   for (i = 0; i < nimages; i++) {
  

•           if (!guidcmp(&img_entry[i].image_type_uuid, img_type_id)) {
  

•                   img_bank_info = &img_entry[i].img_bank_info[bank];
  

•                   if (action == IMAGE_ACCEPT_SET)
  

•                           img_bank_info->accepted |= FWU_IMAGE_ACCEPTED;
  

•                   else
  

•                           img_bank_info->accepted = 0;
  

•                   buf = &mdata->version;
  

•                   mdata->crc32 = crc32(0, buf, sizeof(*mdata) -
  

•                                        sizeof(u32));
  

•                   ret = gpt_update_mdata(mdata);
  

This function is also doing the generic things. Only gpt_update_mdata() is the barrier. I would like to suggest you to add ".update_mdata" member to the fwu_mdata_ops.

Thank you,

•                   goto out;
  

•           }
  

•   }
  

•   /* Image not found */
  

•   ret = -EINVAL;
  

+out:

•   free(mdata);
  

•   return ret;
  

+}

+int fwu_gpt_accept_image(efi_guid_t *img_type_id) +{

•   return fwu_gpt_set_clear_image_accept(img_type_id, 0,
  

•                                         IMAGE_ACCEPT_SET);
  

+}

+int fwu_gpt_clear_accept_image(efi_guid_t *img_type_id, u32 bank) +{

•   return fwu_gpt_set_clear_image_accept(img_type_id, bank,
  

•                                         IMAGE_ACCEPT_CLEAR);
  

+}

+struct fwu_mdata_ops fwu_gpt_blk_ops = {

•   .get_active_index = fwu_gpt_get_active_index,
  

•   .update_active_index = fwu_gpt_update_active_index,
  

•   .get_image_alt_num = fwu_gpt_get_image_alt_num,
  

•   .mdata_check = fwu_gpt_mdata_check,
  

•   .revert_boot_index = fwu_gpt_revert_boot_index,
  

•   .set_accept_image = fwu_gpt_accept_image,
  

•   .clear_accept_image = fwu_gpt_clear_accept_image,
  

•   .get_mdata = fwu_gpt_get_mdata,
  

+};

2.17.1