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Diffstat (limited to 'lib/fwu_updates/fwu.c')
| -rw-r--r-- | lib/fwu_updates/fwu.c | 719 |
1 files changed, 719 insertions, 0 deletions
diff --git a/lib/fwu_updates/fwu.c b/lib/fwu_updates/fwu.c new file mode 100644 index 0000000..5313d07 --- /dev/null +++ b/lib/fwu_updates/fwu.c @@ -0,0 +1,719 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2022, Linaro Limited + */ + +#include <dm.h> +#include <efi.h> +#include <efi_loader.h> +#include <efi_variable.h> +#include <event.h> +#include <fwu.h> +#include <fwu_mdata.h> +#include <malloc.h> + +#include <linux/errno.h> +#include <linux/types.h> + +static u8 in_trial; +static u8 boottime_check; + +#include <linux/errno.h> +#include <linux/types.h> +#include <u-boot/crc.h> + +enum { + IMAGE_ACCEPT_SET = 1, + IMAGE_ACCEPT_CLEAR, +}; + +enum { + PRIMARY_PART = 1, + SECONDARY_PART, + BOTH_PARTS, +}; + +static int fwu_get_dev_mdata(struct udevice **dev, struct fwu_mdata *mdata) +{ + int ret; + + ret = uclass_first_device_err(UCLASS_FWU_MDATA, dev); + if (ret) { + log_debug("Cannot find fwu device\n"); + return ret; + } + + if (!mdata) + return 0; + + ret = fwu_get_mdata(*dev, mdata); + if (ret < 0) + log_debug("Unable to get valid FWU metadata\n"); + + return ret; +} + +static int trial_counter_update(u16 *trial_state_ctr) +{ + bool delete; + u32 var_attr; + efi_status_t status; + efi_uintn_t var_size; + + delete = !trial_state_ctr ? true : false; + var_size = !trial_state_ctr ? 0 : (efi_uintn_t)sizeof(*trial_state_ctr); + var_attr = !trial_state_ctr ? 0 : EFI_VARIABLE_NON_VOLATILE | + EFI_VARIABLE_BOOTSERVICE_ACCESS; + status = efi_set_variable_int(u"TrialStateCtr", + &efi_global_variable_guid, + var_attr, + var_size, trial_state_ctr, false); + + if ((delete && (status != EFI_NOT_FOUND && + status != EFI_SUCCESS)) || + (!delete && status != EFI_SUCCESS)) + return -1; + + return 0; +} + +static int trial_counter_read(u16 *trial_state_ctr) +{ + efi_status_t status; + efi_uintn_t var_size; + + var_size = (efi_uintn_t)sizeof(trial_state_ctr); + status = efi_get_variable_int(u"TrialStateCtr", + &efi_global_variable_guid, + NULL, + &var_size, trial_state_ctr, + NULL); + if (status != EFI_SUCCESS) { + log_err("Unable to read TrialStateCtr variable\n"); + return -1; + } + + return 0; +} + +static int fwu_trial_count_update(void) +{ + int ret; + u16 trial_state_ctr; + + ret = trial_counter_read(&trial_state_ctr); + if (ret) { + log_debug("Unable to read trial_state_ctr\n"); + goto out; + } + + ++trial_state_ctr; + if (trial_state_ctr > CONFIG_FWU_TRIAL_STATE_CNT) { + log_info("Trial State count exceeded. Revert back to previous_active_index\n"); + ret = fwu_revert_boot_index(); + if (ret) + log_err("Unable to revert active_index\n"); + ret = 1; + } else { + ret = trial_counter_update(&trial_state_ctr); + if (ret) + log_err("Unable to increment TrialStateCtr variable\n"); + } + +out: + return ret; +} + +static int in_trial_state(struct fwu_mdata *mdata) +{ + u32 i, active_bank; + struct fwu_image_entry *img_entry; + struct fwu_image_bank_info *img_bank_info; + + active_bank = mdata->active_index; + img_entry = &mdata->img_entry[0]; + for (i = 0; i < CONFIG_FWU_NUM_IMAGES_PER_BANK; i++) { + img_bank_info = &img_entry[i].img_bank_info[active_bank]; + if (!img_bank_info->accepted) { + log_info("System booting in Trial State\n"); + return 1; + } + } + + return 0; +} + +static int fwu_get_image_type_id(u8 *image_index, efi_guid_t *image_type_id) +{ + u8 index; + int i; + struct efi_fw_image *image; + + index = *image_index; + image = update_info.images; + for (i = 0; i < num_image_type_guids; i++) { + if (index == image[i].image_index) { + guidcpy(image_type_id, &image[i].image_type_id); + return 0; + } + } + + return -ENOENT; +} + +/** + * 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_debug("crc32 check failed for %s FWU metadata partition\n", + pri_part ? "primary" : "secondary"); + return -EINVAL; + } + + return 0; +} + +/** + * fwu_check_mdata_validity() - Check for validity of the FWU metadata copies + * + * Read both the metadata copies from the storage media, verify their checksum, + * and ascertain that both copies match. If one of the copies has gone bad, + * restore it from the good copy. + * + * Return: 0 if OK, -ve on error + * + */ +int fwu_check_mdata_validity(void) +{ + int ret; + struct udevice *dev; + struct fwu_mdata pri_mdata; + struct fwu_mdata secondary_mdata; + uint mdata_parts[2]; + uint valid_partitions, invalid_partitions; + + ret = fwu_get_dev_mdata(&dev, NULL); + if (ret) + return ret; + + /* + * Check if the platform has defined its own + * function to check the metadata partitions' + * validity. If so, that takes precedence. + */ + ret = fwu_mdata_check(dev); + if (!ret || ret != -ENOSYS) + return ret; + + /* + * Two FWU metadata partitions are expected. + * If we don't have two, user needs to create + * them first + */ + valid_partitions = 0; + ret = fwu_get_mdata_part_num(dev, mdata_parts); + if (ret < 0) { + log_debug("Error getting the FWU metadata partitions\n"); + return -ENOENT; + } + + ret = fwu_read_mdata_partition(dev, &pri_mdata, mdata_parts[0]); + if (!ret) { + ret = fwu_verify_mdata(&pri_mdata, 1); + if (!ret) + valid_partitions |= PRIMARY_PART; + } + + ret = fwu_read_mdata_partition(dev, &secondary_mdata, mdata_parts[1]); + if (!ret) { + ret = fwu_verify_mdata(&secondary_mdata, 0); + if (!ret) + valid_partitions |= SECONDARY_PART; + } + + if (valid_partitions == (PRIMARY_PART | SECONDARY_PART)) { + /* + * Before returning, check that both the + * FWU metadata copies are the same. If not, + * populate the secondary partition from the + * primary partition copy. + */ + if (!memcmp(&pri_mdata, &secondary_mdata, + sizeof(struct fwu_mdata))) { + ret = 0; + } else { + log_info("Both FWU metadata copies are valid but do not match."); + log_info(" Restoring the secondary partition from the primary\n"); + ret = fwu_write_mdata_partition(dev, &pri_mdata, + mdata_parts[1]); + if (ret) + log_debug("Restoring secondary FWU metadata partition failed\n"); + } + goto out; + } + + if (!(valid_partitions & BOTH_PARTS)) { + log_info("Both FWU metadata partitions invalid\n"); + ret = -EBADMSG; + goto out; + } + + invalid_partitions = valid_partitions ^ BOTH_PARTS; + ret = fwu_write_mdata_partition(dev, + (invalid_partitions == PRIMARY_PART) ? + &secondary_mdata : &pri_mdata, + (invalid_partitions == PRIMARY_PART) ? + mdata_parts[0] : mdata_parts[1]); + + if (ret) + log_debug("Restoring %s FWU metadata partition failed\n", + (invalid_partitions == PRIMARY_PART) ? + "primary" : "secondary"); + +out: + return ret; +} + +/** + * fwu_get_active_index() - Get active_index from the FWU metadata + * @active_idx: active_index value to be read + * + * Read the active_index field from the FWU metadata and place it in + * the variable pointed to be the function argument. + * + * Return: 0 if OK, -ve on error + * + */ +int fwu_get_active_index(uint *active_idx) +{ + int ret; + struct udevice *dev; + struct fwu_mdata mdata = { 0 }; + + ret = fwu_get_dev_mdata(&dev, &mdata); + if (ret) + return ret; + + /* + * Found the FWU metadata partition, now read the active_index + * value + */ + *active_idx = mdata.active_index; + if (*active_idx >= CONFIG_FWU_NUM_BANKS) { + log_debug("Active index value read is incorrect\n"); + ret = -EINVAL; + } + + return ret; +} + +/** + * fwu_set_active_index() - Set active_index in the FWU metadata + * @active_idx: active_index value to be set + * + * Update the active_index field in the FWU metadata + * + * Return: 0 if OK, -ve on error + * + */ +int fwu_set_active_index(uint active_idx) +{ + int ret; + struct udevice *dev; + struct fwu_mdata mdata = { 0 }; + + if (active_idx >= CONFIG_FWU_NUM_BANKS) { + log_debug("Invalid active index value\n"); + return -EINVAL; + } + + ret = fwu_get_dev_mdata(&dev, &mdata); + if (ret) + return ret; + + /* + * 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; + + /* + * Now write this updated FWU metadata to both the + * FWU metadata partitions + */ + ret = fwu_update_mdata(dev, &mdata); + if (ret) { + log_debug("Failed to update FWU metadata partitions\n"); + ret = -EIO; + } + + return ret; +} + +/** + * fwu_get_image_index() - Get the Image Index to be used for capsule update + * @image_index: The Image Index for the image + * + * The FWU multi bank update feature computes the value of image_index at + * runtime, based on the bank to which the image needs to be written to. + * Derive the image_index value for the image. + * + * Currently, the capsule update driver uses the DFU framework for + * the updates. This function gets the DFU alt number which is to + * be used as the Image Index + * + * Return: 0 if OK, -ve on error + * + */ +int fwu_get_image_index(u8 *image_index) +{ + int ret, i; + u8 alt_num; + uint update_bank; + efi_guid_t *image_guid, image_type_id; + struct udevice *dev; + struct fwu_mdata mdata = { 0 }; + struct fwu_image_entry *img_entry; + struct fwu_image_bank_info *img_bank_info; + + ret = fwu_get_dev_mdata(&dev, &mdata); + if (ret) + return ret; + + ret = fwu_plat_get_update_index(&update_bank); + if (ret) { + log_debug("Failed to get the FWU update bank\n"); + goto out; + } + + ret = fwu_get_image_type_id(image_index, &image_type_id); + if (ret) { + log_debug("Unable to get image_type_id for image_index %u\n", + *image_index); + goto out; + } + + ret = -EINVAL; + /* + * 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]; + image_guid = &img_bank_info->image_uuid; + ret = fwu_plat_get_alt_num(dev, image_guid, &alt_num); + if (ret) { + log_debug("alt_num not found for partition with GUID %pUs\n", + image_guid); + } else { + log_debug("alt_num %d for partition %pUs\n", + alt_num, image_guid); + *image_index = alt_num + 1; + } + + goto out; + } + } + + log_debug("Partition with the image type %pUs not found\n", + &image_type_id); + +out: + return ret; +} + +/** + * fwu_revert_boot_index() - Revert the active index in the FWU metadata + * + * Revert the active_index value in the FWU metadata, by swapping the values + * of active_index and previous_active_index in both copies of the + * FWU metadata. + * + * Return: 0 if OK, -ve on error + * + */ +int fwu_revert_boot_index(void) +{ + int ret; + u32 cur_active_index; + struct udevice *dev; + struct fwu_mdata mdata = { 0 }; + + ret = fwu_get_dev_mdata(&dev, &mdata); + if (ret) + return ret; + + /* + * 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; + + /* + * Now write this updated FWU metadata to both the + * FWU metadata partitions + */ + ret = fwu_update_mdata(dev, &mdata); + if (ret) { + log_debug("Failed to update FWU metadata partitions\n"); + ret = -EIO; + } + + return ret; +} + +/** + * fwu_clrset_image_accept() - Set or Clear the Acceptance bit for the image + * @img_type_id: GUID of the image type for which the accepted bit is to be + * set or cleared + * @bank: Bank of which the image's Accept bit is to be set or cleared + * @action: Action which specifies whether image's Accept bit is to be set or + * cleared + * + * Set/Clear the accepted bit for the image specified by the img_guid parameter. + * This indicates acceptance or rejection of image for subsequent boots by some + * governing component like OS(or firmware). + * + * Return: 0 if OK, -ve on error + * + */ +static int fwu_clrset_image_accept(efi_guid_t *img_type_id, u32 bank, u8 action) +{ + int ret, i; + struct udevice *dev; + struct fwu_mdata mdata = { 0 }; + struct fwu_image_entry *img_entry; + struct fwu_image_bank_info *img_bank_info; + + ret = fwu_get_dev_mdata(&dev, &mdata); + if (ret) + return ret; + + img_entry = &mdata.img_entry[0]; + for (i = 0; i < CONFIG_FWU_NUM_IMAGES_PER_BANK; 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; + + ret = fwu_update_mdata(dev, &mdata); + goto out; + } + } + + /* Image not found */ + ret = -ENOENT; + +out: + return ret; +} + +/** + * fwu_accept_image() - Set the Acceptance bit for the image + * @img_type_id: GUID of the image type for which the accepted bit is to be + * cleared + * @bank: Bank of which the image's Accept bit is to be set + * + * Set the accepted bit for the image specified by the img_guid parameter. This + * indicates acceptance of image for subsequent boots by some governing component + * like OS(or firmware). + * + * Return: 0 if OK, -ve on error + * + */ +int fwu_accept_image(efi_guid_t *img_type_id, u32 bank) +{ + return fwu_clrset_image_accept(img_type_id, bank, + IMAGE_ACCEPT_SET); +} + +/** + * fwu_clear_accept_image() - Clear the Acceptance bit for the image + * @img_type_id: GUID of the image type for which the accepted bit is to be + * cleared + * @bank: Bank of which the image's Accept bit is to be cleared + * + * Clear the accepted bit for the image type specified by the img_type_id parameter. + * This function is called after the image has been updated. The accepted bit is + * cleared to be set subsequently after passing the image acceptance criteria, by + * either the OS(or firmware) + * + * Return: 0 if OK, -ve on error + * + */ +int fwu_clear_accept_image(efi_guid_t *img_type_id, u32 bank) +{ + return fwu_clrset_image_accept(img_type_id, bank, + IMAGE_ACCEPT_CLEAR); +} + +/** + * fwu_plat_get_update_index() - Get the value of the update bank + * @update_idx: Bank number to which images are to be updated + * + * Get the value of the bank(partition) to which the update needs to be + * made. + * + * Note: This is a weak function and platforms can override this with + * their own implementation for selection of the update bank. + * + * Return: 0 if OK, -ve on error + * + */ +__weak int fwu_plat_get_update_index(uint *update_idx) +{ + int ret; + u32 active_idx; + + ret = fwu_get_active_index(&active_idx); + if (ret < 0) + return -1; + + *update_idx = (active_idx + 1) % CONFIG_FWU_NUM_BANKS; + + return ret; +} + +/** + * fwu_update_checks_pass() - Check if FWU update can be done + * + * Check if the FWU update can be executed. The updates are + * allowed only when the platform is not in Trial State and + * the boot time checks have passed + * + * Return: 1 if OK, 0 if checks do not pass + * + */ +u8 fwu_update_checks_pass(void) +{ + return !in_trial && boottime_check; +} + +/** + * fwu_empty_capsule_checks_pass() - Check if empty capsule can be processed + * + * Check if the empty capsule can be processed to either accept or revert + * an earlier executed update. The empty capsules need to be processed + * only when the platform is in Trial State and the boot time checks have + * passed + * + * Return: 1 if OK, 0 if not to be allowed + * + */ +u8 fwu_empty_capsule_checks_pass(void) +{ + return in_trial && boottime_check; +} + +/** + * fwu_trial_state_ctr_start() - Start the Trial State counter + * + * Start the counter to identify the platform booting in the + * Trial State. The counter is implemented as an EFI variable. + * + * Return: 0 if OK, -ve on error + * + */ +int fwu_trial_state_ctr_start(void) +{ + int ret; + u16 trial_state_ctr; + + trial_state_ctr = 0; + ret = trial_counter_update(&trial_state_ctr); + if (ret) + log_err("Unable to initialise TrialStateCtr\n"); + + return ret; +} + +static int fwu_boottime_checks(void *ctx, struct event *event) +{ + int ret; + u32 boot_idx, active_idx; + struct udevice *dev; + struct fwu_mdata mdata = { 0 }; + + /* Don't have boot time checks on sandbox */ + if (IS_ENABLED(CONFIG_SANDBOX)) { + boottime_check = 1; + return 0; + } + + ret = fwu_check_mdata_validity(); + if (ret) + return 0; + + /* + * Get the Boot Index, i.e. the bank from + * which the platform has booted. This value + * gets passed from the ealier stage bootloader + * which booted u-boot, e.g. tf-a. If the + * boot index is not the same as the + * active_index read from the FWU metadata, + * update the active_index. + */ + fwu_plat_get_bootidx(&boot_idx); + if (boot_idx >= CONFIG_FWU_NUM_BANKS) { + log_err("Received incorrect value of boot_index\n"); + return 0; + } + + ret = fwu_get_active_index(&active_idx); + if (ret) { + log_err("Unable to read active_index\n"); + return 0; + } + + if (boot_idx != active_idx) { + log_info("Boot idx %u is not matching active idx %u, changing active_idx\n", + boot_idx, active_idx); + ret = fwu_set_active_index(boot_idx); + if (!ret) + boottime_check = 1; + + return 0; + } + + if (efi_init_obj_list() != EFI_SUCCESS) + return 0; + + ret = fwu_get_dev_mdata(&dev, &mdata); + if (ret) + return ret; + + in_trial = in_trial_state(&mdata); + if (!in_trial || (ret = fwu_trial_count_update()) > 0) + ret = trial_counter_update(NULL); + + if (!ret) + boottime_check = 1; + + return 0; +} +EVENT_SPY(EVT_MAIN_LOOP, fwu_boottime_checks); |