[RFC PATCH v3 2/9] FWU: Add FWU metadata access functions for GPT partitioned block devices
Sughosh Ganu
sughosh.ganu at linaro.org
Wed Jan 19 19:55:41 CET 2022
In the FWU Multi Bank Update feature, the information about the
updatable images is stored as part of the metadata, on a separate
partition. Add functions for reading from and writing to the metadata
when the updatable images and the metadata are stored on a block
device which is formated with GPT based partition scheme.
Signed-off-by: Sughosh Ganu <sughosh.ganu at linaro.org>
---
Changes since V2:
* Move the function definition of fwu_verify_mdata to fwu_mdata.c to
facilitate reuse
* Remove the block device specific desc->devnum parameter for the
fwu_plat_get_alt_num function call
include/fwu.h | 1 +
include/fwu_mdata.h | 2 +
lib/fwu_updates/fwu_mdata.c | 29 ++
lib/fwu_updates/fwu_mdata_gpt_blk.c | 520 ++++++++++++++++++++++++++++
4 files changed, 552 insertions(+)
create mode 100644 lib/fwu_updates/fwu_mdata_gpt_blk.c
diff --git a/include/fwu.h b/include/fwu.h
index acba725bc8..12f7eecdb0 100644
--- a/include/fwu.h
+++ b/include/fwu.h
@@ -53,6 +53,7 @@ int fwu_get_active_index(u32 *active_idx);
int fwu_update_active_index(u32 active_idx);
int fwu_get_image_alt_num(efi_guid_t image_type_id, u32 update_bank,
int *alt_num);
+int fwu_verify_mdata(struct fwu_mdata *mdata, bool pri_part);
int fwu_mdata_check(void);
int fwu_revert_boot_index(void);
int fwu_accept_image(efi_guid_t *img_type_id, u32 bank);
diff --git a/include/fwu_mdata.h b/include/fwu_mdata.h
index d788eb69e7..53e39f9af6 100644
--- a/include/fwu_mdata.h
+++ b/include/fwu_mdata.h
@@ -64,4 +64,6 @@ struct fwu_mdata {
struct fwu_image_entry img_entry[CONFIG_FWU_NUM_IMAGES_PER_BANK];
} __attribute__((__packed__));
+extern struct fwu_mdata_ops fwu_gpt_blk_ops;
+
#endif /* _FWU_MDATA_H_ */
diff --git a/lib/fwu_updates/fwu_mdata.c b/lib/fwu_updates/fwu_mdata.c
index 58e838fe28..252fcf50f6 100644
--- a/lib/fwu_updates/fwu_mdata.c
+++ b/lib/fwu_updates/fwu_mdata.c
@@ -25,6 +25,35 @@ static struct fwu_mdata_ops *get_fwu_mdata_ops(void)
return ops;
}
+/**
+ * fwu_verify_mdata() - Verify the FWU metadata
+ * @mdata: FWU metadata structure
+ * @pri_part: FWU metadata partition is primary or secondary
+ *
+ * Verify the FWU metadata by computing the CRC32 for the metadata
+ * structure and comparing it against the CRC32 value stored as part
+ * of the structure.
+ *
+ * Return: 0 if OK, -ve on error
+ *
+ */
+int fwu_verify_mdata(struct fwu_mdata *mdata, bool pri_part)
+{
+ u32 calc_crc32;
+ void *buf;
+
+ buf = &mdata->version;
+ calc_crc32 = crc32(0, buf, sizeof(*mdata) - sizeof(u32));
+
+ if (calc_crc32 != mdata->crc32) {
+ log_err("crc32 check failed for %s FWU metadata partition\n",
+ pri_part ? "primary" : "secondary");
+ return -1;
+ }
+
+ return 0;
+}
+
/**
* fwu_get_active_index() - Get active_index from the FWU metadata
* @active_idx: active_index value to be read
diff --git a/lib/fwu_updates/fwu_mdata_gpt_blk.c b/lib/fwu_updates/fwu_mdata_gpt_blk.c
new file mode 100644
index 0000000000..cb47ddf4a7
--- /dev/null
+++ b/lib/fwu_updates/fwu_mdata_gpt_blk.c
@@ -0,0 +1,520 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2021, Linaro Limited
+ */
+
+#include <blk.h>
+#include <efi_loader.h>
+#include <fwu.h>
+#include <fwu_mdata.h>
+#include <log.h>
+#include <malloc.h>
+#include <memalign.h>
+#include <part.h>
+#include <part_efi.h>
+
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <u-boot/crc.h>
+
+#define PRIMARY_PART BIT(0)
+#define SECONDARY_PART BIT(1)
+#define BOTH_PARTS (PRIMARY_PART | SECONDARY_PART)
+
+#define MDATA_READ BIT(0)
+#define MDATA_WRITE BIT(1)
+
+#define IMAGE_ACCEPT_SET BIT(0)
+#define IMAGE_ACCEPT_CLEAR BIT(1)
+
+static int gpt_get_mdata_partitions(struct blk_desc *desc,
+ u16 *primary_mpart,
+ u16 *secondary_mpart)
+{
+ int i, ret;
+ u32 mdata_parts;
+ efi_guid_t part_type_guid;
+ struct disk_partition info;
+ const efi_guid_t fwu_mdata_guid = FWU_MDATA_GUID;
+
+ for (i = 1; i < MAX_SEARCH_PARTITIONS; i++) {
+ if (part_get_info(desc, i, &info))
+ continue;
+ uuid_str_to_bin(info.type_guid, part_type_guid.b,
+ UUID_STR_FORMAT_GUID);
+
+ if (!guidcmp(&fwu_mdata_guid, &part_type_guid)) {
+ ++mdata_parts;
+ if (!*primary_mpart)
+ *primary_mpart = i;
+ else
+ *secondary_mpart = i;
+ }
+ }
+
+ if (mdata_parts != 2) {
+ log_err("Expect two copies of the FWU metadata instead of %d\n",
+ mdata_parts);
+ ret = -EINVAL;
+ } else {
+ ret = 0;
+ }
+
+ return ret;
+}
+
+static int gpt_get_mdata_disk_part(struct blk_desc *desc,
+ struct disk_partition *info,
+ u32 part_num)
+{
+ int ret;
+ char *mdata_guid_str = "8a7a84a0-8387-40f6-ab41-a8b9a5a60d23";
+
+ ret = part_get_info(desc, part_num, info);
+ if (ret < 0) {
+ log_err("Unable to get the partition info for the FWU metadata part %d",
+ part_num);
+ return -1;
+ }
+
+ /* Check that it is indeed the FWU metadata partition */
+ if (!strncmp(info->type_guid, mdata_guid_str, UUID_STR_LEN)) {
+ /* Found the FWU metadata partition */
+ return 0;
+ }
+
+ return -1;
+}
+
+static int gpt_read_write_mdata(struct blk_desc *desc,
+ struct fwu_mdata *mdata,
+ u8 access, u32 part_num)
+{
+ int ret;
+ u32 len, blk_start, blkcnt;
+ struct disk_partition info;
+
+ ALLOC_CACHE_ALIGN_BUFFER_PAD(struct fwu_mdata, mdata_aligned, 1,
+ desc->blksz);
+
+ ret = gpt_get_mdata_disk_part(desc, &info, part_num);
+ if (ret < 0) {
+ printf("Unable to get the FWU metadata partition\n");
+ return -ENODEV;
+ }
+
+ len = sizeof(*mdata);
+ blkcnt = BLOCK_CNT(len, desc);
+ if (blkcnt > info.size) {
+ log_err("Block count exceeds FWU metadata partition size\n");
+ return -ERANGE;
+ }
+
+ blk_start = info.start;
+ if (access == MDATA_READ) {
+ if (blk_dread(desc, blk_start, blkcnt, mdata_aligned) != blkcnt) {
+ log_err("Error reading FWU metadata from the device\n");
+ return -EIO;
+ }
+ memcpy(mdata, mdata_aligned, sizeof(struct fwu_mdata));
+ } else {
+ if (blk_dwrite(desc, blk_start, blkcnt, mdata) != blkcnt) {
+ log_err("Error writing FWU metadata to the device\n");
+ return -EIO;
+ }
+ }
+
+ return 0;
+}
+
+static int gpt_read_mdata(struct blk_desc *desc,
+ struct fwu_mdata *mdata, u32 part_num)
+{
+ return gpt_read_write_mdata(desc, mdata, MDATA_READ, part_num);
+}
+
+static int gpt_write_mdata_partition(struct blk_desc *desc,
+ struct fwu_mdata *mdata,
+ u32 part_num)
+{
+ return gpt_read_write_mdata(desc, mdata, MDATA_WRITE, part_num);
+}
+
+static int fwu_gpt_update_mdata(struct fwu_mdata *mdata)
+{
+ int ret;
+ struct blk_desc *desc;
+ u16 primary_mpart = 0, secondary_mpart = 0;
+
+ ret = fwu_plat_get_blk_desc(&desc);
+ if (ret < 0) {
+ log_err("Block device not found\n");
+ return -ENODEV;
+ }
+
+ ret = gpt_get_mdata_partitions(desc, &primary_mpart,
+ &secondary_mpart);
+
+ if (ret < 0) {
+ log_err("Error getting the FWU metadata partitions\n");
+ return -ENODEV;
+ }
+
+ /* First write the primary partition*/
+ ret = gpt_write_mdata_partition(desc, mdata, primary_mpart);
+ if (ret < 0) {
+ log_err("Updating primary FWU metadata partition failed\n");
+ return ret;
+ }
+
+ /* And now the replica */
+ ret = gpt_write_mdata_partition(desc, mdata, secondary_mpart);
+ if (ret < 0) {
+ log_err("Updating secondary FWU metadata partition failed\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static int gpt_get_mdata(struct fwu_mdata **mdata)
+{
+ int ret;
+ struct blk_desc *desc;
+ u16 primary_mpart = 0, secondary_mpart = 0;
+
+ ret = fwu_plat_get_blk_desc(&desc);
+ if (ret < 0) {
+ log_err("Block device not found\n");
+ return -ENODEV;
+ }
+
+ ret = gpt_get_mdata_partitions(desc, &primary_mpart,
+ &secondary_mpart);
+
+ if (ret < 0) {
+ log_err("Error getting the FWU metadata partitions\n");
+ return -ENODEV;
+ }
+
+ *mdata = malloc(sizeof(struct fwu_mdata));
+ if (!*mdata) {
+ log_err("Unable to allocate memory for reading FWU metadata\n");
+ return -ENOMEM;
+ }
+
+ ret = gpt_read_mdata(desc, *mdata, primary_mpart);
+ if (ret < 0) {
+ log_err("Failed to read the FWU metadata from the device\n");
+ return -EIO;
+ }
+
+ ret = fwu_verify_mdata(*mdata, 1);
+ if (!ret)
+ return 0;
+
+ /*
+ * Verification of the primary FWU metadata copy failed.
+ * Try to read the replica.
+ */
+ memset(*mdata, 0, sizeof(struct fwu_mdata));
+ ret = gpt_read_mdata(desc, *mdata, secondary_mpart);
+ if (ret < 0) {
+ log_err("Failed to read the FWU metadata from the device\n");
+ return -EIO;
+ }
+
+ ret = fwu_verify_mdata(*mdata, 0);
+ if (!ret)
+ return 0;
+
+ /* Both the FWU metadata copies are corrupted. */
+ return -1;
+}
+
+static int gpt_check_mdata_validity(void)
+{
+ int ret;
+ struct blk_desc *desc;
+ struct fwu_mdata pri_mdata;
+ struct fwu_mdata secondary_mdata;
+ u16 primary_mpart = 0, secondary_mpart = 0;
+ u16 valid_partitions, invalid_partitions;
+
+ ret = fwu_plat_get_blk_desc(&desc);
+ if (ret < 0) {
+ log_err("Block device not found\n");
+ return -ENODEV;
+ }
+
+ /*
+ * Two FWU metadata partitions are expected.
+ * If we don't have two, user needs to create
+ * them first
+ */
+ valid_partitions = 0;
+ ret = gpt_get_mdata_partitions(desc, &primary_mpart,
+ &secondary_mpart);
+
+ if (ret < 0) {
+ log_err("Error getting the FWU metadata partitions\n");
+ return -ENODEV;
+ }
+
+ ret = gpt_read_mdata(desc, &pri_mdata, primary_mpart);
+ if (ret < 0) {
+ log_err("Failed to read the FWU metadata from the device\n");
+ goto secondary_read;
+ }
+
+ ret = fwu_verify_mdata(&pri_mdata, 1);
+ if (!ret)
+ valid_partitions |= PRIMARY_PART;
+
+secondary_read:
+ /* Now check the secondary partition */
+ ret = gpt_read_mdata(desc, &secondary_mdata, secondary_mpart);
+ if (ret < 0) {
+ log_err("Failed to read the FWU metadata from the device\n");
+ goto mdata_restore;
+ }
+
+ ret = fwu_verify_mdata(&secondary_mdata, 0);
+ if (!ret)
+ valid_partitions |= SECONDARY_PART;
+
+mdata_restore:
+ if (valid_partitions == (PRIMARY_PART | SECONDARY_PART)) {
+ ret = -1;
+ /*
+ * Before returning, check that both the
+ * FWU metadata copies are the same. If not,
+ * the FWU metadata copies need to be
+ * re-populated.
+ */
+ if (!memcmp(&pri_mdata, &secondary_mdata,
+ sizeof(struct fwu_mdata))) {
+ ret = 0;
+ } else {
+ log_err("Both FWU metadata copies are valid but do not match. Please check!\n");
+ }
+ goto out;
+ }
+
+ ret = -1;
+ if (!(valid_partitions & BOTH_PARTS))
+ goto out;
+
+ invalid_partitions = valid_partitions ^ BOTH_PARTS;
+ ret = gpt_write_mdata_partition(desc,
+ (invalid_partitions == PRIMARY_PART) ?
+ &secondary_mdata : &pri_mdata,
+ (invalid_partitions == PRIMARY_PART) ?
+ primary_mpart : secondary_mpart);
+
+ if (ret < 0)
+ log_err("Restoring %s FWU metadata partition failed\n",
+ (invalid_partitions == PRIMARY_PART) ?
+ "primary" : "secondary");
+
+out:
+ return ret;
+}
+
+int fwu_gpt_get_active_index(u32 *active_idx)
+{
+ int ret;
+ struct fwu_mdata *mdata;
+
+ ret = gpt_get_mdata(&mdata);
+ if (ret < 0) {
+ log_err("Unable to get valid FWU metadata\n");
+ goto out;
+ }
+
+ /*
+ * Found the FWU metadata partition, now read the active_index
+ * value
+ */
+ *active_idx = mdata->active_index;
+ if (*active_idx > CONFIG_FWU_NUM_BANKS - 1) {
+ printf("Active index value read is incorrect\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+out:
+ free(mdata);
+
+ return ret;
+}
+
+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(&part);
+ 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_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);
+}
+
+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;
+ }
+
+ 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 = fwu_gpt_update_mdata(mdata);
+ goto out;
+ }
+ }
+
+ /* Image not found */
+ ret = -EINVAL;
+
+out:
+ free(mdata);
+
+ return ret;
+}
+
+static int fwu_gpt_accept_image(efi_guid_t *img_type_id, u32 bank)
+{
+ return fwu_gpt_set_clear_image_accept(img_type_id, bank,
+ IMAGE_ACCEPT_SET);
+}
+
+static 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,
+ .get_image_alt_num = fwu_gpt_get_image_alt_num,
+ .mdata_check = fwu_gpt_mdata_check,
+ .set_accept_image = fwu_gpt_accept_image,
+ .clear_accept_image = fwu_gpt_clear_accept_image,
+ .get_mdata = fwu_gpt_get_mdata,
+ .update_mdata = fwu_gpt_update_mdata,
+};
--
2.17.1
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