FWU: Add support for the FWU Multi Bank Update feature

The FWU Multi Bank Update feature supports updating firmware images
to one of multiple sets(also called banks) of images. The firmware
images are clubbed together in banks, with the system booting images
from the active bank. Information on the images such as which bank
they belong to is stored as part of the metadata structure, which is
stored on the same storage media as the firmware images on a dedicated
partition.

At the time of update, the metadata is read to identify the bank to
which the images need to be flashed(update bank). On a successful
update, the metadata is modified to set the updated bank as active
bank to subsequently boot from.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

1 files changed, 208 insertions, 2 deletions

diff --git a/lib/efi_loader/efi_capsule.c b/lib/efi_loader/efi_capsule.c
index 397e393a188..1163a2ee301 100644
--- a/lib/efi_loader/efi_capsule.c
+++ b/lib/efi_loader/efi_capsule.c
@@ -14,6 +14,7 @@
 #include <env.h>
 #include <fdtdec.h>
 #include <fs.h>
+#include <fwu.h>
 #include <hang.h>
 #include <malloc.h>
 #include <mapmem.h>
@@ -32,6 +33,12 @@ static const efi_guid_t efi_guid_firmware_management_capsule_id =
 		EFI_FIRMWARE_MANAGEMENT_CAPSULE_ID_GUID;
 const efi_guid_t efi_guid_firmware_management_protocol =
 		EFI_FIRMWARE_MANAGEMENT_PROTOCOL_GUID;
+const efi_guid_t fwu_guid_os_request_fw_revert =
+		FWU_OS_REQUEST_FW_REVERT_GUID;
+const efi_guid_t fwu_guid_os_request_fw_accept =
+		FWU_OS_REQUEST_FW_ACCEPT_GUID;
+
+#define FW_ACCEPT_OS	(u32)0x8000
 
 #ifdef CONFIG_EFI_CAPSULE_ON_DISK
 /* for file system access */
@@ -386,6 +393,132 @@ efi_status_t efi_capsule_authenticate(const void *capsule, efi_uintn_t capsule_s
 }
 #endif /* CONFIG_EFI_CAPSULE_AUTHENTICATE */
 
+static __maybe_unused bool fwu_empty_capsule(struct efi_capsule_header *capsule)
+{
+	return !guidcmp(&capsule->capsule_guid,
+			&fwu_guid_os_request_fw_revert) ||
+		!guidcmp(&capsule->capsule_guid,
+			 &fwu_guid_os_request_fw_accept);
+}
+
+static __maybe_unused efi_status_t fwu_to_efi_error(int err)
+{
+	efi_status_t ret;
+
+	switch(err) {
+	case 0:
+		ret = EFI_SUCCESS;
+		break;
+	case -ERANGE:
+	case -EIO:
+		ret = EFI_DEVICE_ERROR;
+		break;
+	case -EINVAL:
+		ret = EFI_INVALID_PARAMETER;
+		break;
+	case -ENODEV:
+		ret = EFI_NOT_FOUND;
+		break;
+	default:
+		ret = EFI_OUT_OF_RESOURCES;
+	}
+
+	return ret;
+}
+
+static __maybe_unused efi_status_t fwu_empty_capsule_process(
+	struct efi_capsule_header *capsule)
+{
+	int status;
+	u32 active_idx;
+	efi_guid_t *image_guid;
+	efi_status_t ret = EFI_INVALID_PARAMETER;
+
+	if (!guidcmp(&capsule->capsule_guid,
+		     &fwu_guid_os_request_fw_revert)) {
+		/*
+		 * One of the previously updated image has
+		 * failed the OS acceptance test. OS has
+		 * requested to revert back to the earlier
+		 * boot index
+		 */
+		status = fwu_revert_boot_index();
+		ret = fwu_to_efi_error(status);
+		if (ret == EFI_SUCCESS)
+			log_debug("Reverted the FWU active_index. Recommend rebooting the system\n");
+		else
+			log_err("Failed to revert the FWU boot index\n");
+	} else if (!guidcmp(&capsule->capsule_guid,
+			    &fwu_guid_os_request_fw_accept)) {
+		/*
+		 * Image accepted by the OS. Set the acceptance
+		 * status for the image.
+		 */
+		image_guid = (void *)(char *)capsule +
+			capsule->header_size;
+
+		status = fwu_get_active_index(&active_idx);
+		ret = fwu_to_efi_error(status);
+		if (ret != EFI_SUCCESS) {
+			log_err("Unable to get the active_index from the FWU metadata\n");
+			return ret;
+		}
+
+		status = fwu_accept_image(image_guid, active_idx);
+		ret = fwu_to_efi_error(status);
+		if (ret != EFI_SUCCESS)
+			log_err("Unable to set the Accept bit for the image %pUs\n",
+				image_guid);
+	}
+
+	return ret;
+}
+
+static __maybe_unused void fwu_post_update_checks(
+	struct efi_capsule_header *capsule,
+	bool *fw_accept_os, bool *capsule_update)
+{
+	if (fwu_empty_capsule(capsule))
+		*capsule_update = false;
+	else
+		if (!*fw_accept_os)
+			*fw_accept_os =
+				capsule->flags & FW_ACCEPT_OS ? true : false;
+}
+
+static __maybe_unused efi_status_t fwu_post_update_process(bool fw_accept_os)
+{
+	int status;
+	uint update_index;
+	efi_status_t ret;
+
+	status = fwu_plat_get_update_index(&update_index);
+	if (status < 0) {
+		log_err("Failed to get the FWU update_index value\n");
+		return EFI_DEVICE_ERROR;
+	}
+
+	/*
+	 * All the capsules have been updated successfully,
+	 * update the FWU metadata.
+	 */
+	log_debug("Update Complete. Now updating active_index to %u\n",
+		  update_index);
+	status = fwu_set_active_index(update_index);
+	ret = fwu_to_efi_error(status);
+	if (ret != EFI_SUCCESS) {
+		log_err("Failed to update FWU metadata index values\n");
+	} else {
+		log_debug("Successfully updated the active_index\n");
+		if (fw_accept_os) {
+			status = fwu_trial_state_ctr_start();
+			if (status < 0)
+				ret = EFI_DEVICE_ERROR;
+		}
+	}
+
+	return ret;
+}
 
 /**
  * efi_capsule_update_firmware - update firmware from capsule
@@ -408,7 +541,32 @@ static efi_status_t efi_capsule_update_firmware(
 	int item;
 	struct efi_firmware_management_protocol *fmp;
 	u16 *abort_reason;
+	efi_guid_t *image_type_id;
 	efi_status_t ret = EFI_SUCCESS;
+	int status;
+	uint update_index;
+	bool fw_accept_os;
+
+	if (IS_ENABLED(CONFIG_FWU_MULTI_BANK_UPDATE)) {
+		if (fwu_empty_capsule_checks_pass() &&
+		    fwu_empty_capsule(capsule_data))
+			return fwu_empty_capsule_process(capsule_data);
+
+		if (!fwu_update_checks_pass()) {
+			log_err("FWU checks failed. Cannot start update\n");
+			return EFI_INVALID_PARAMETER;
+		}
+
+
+		/* Obtain the update_index from the platform */
+		status = fwu_plat_get_update_index(&update_index);
+		if (status < 0) {
+			log_err("Failed to get the FWU update_index value\n");
+			return EFI_DEVICE_ERROR;
+		}
+
+		fw_accept_os = capsule_data->flags & FW_ACCEPT_OS ? 0x1 : 0x0;
+	}
 
 	/* sanity check */
 	if (capsule_data->header_size < sizeof(*capsule) ||
@@ -495,6 +653,34 @@ static efi_status_t efi_capsule_update_firmware(
 			efi_free_pool(abort_reason);
 			goto out;
 		}
+
+		if (IS_ENABLED(CONFIG_FWU_MULTI_BANK_UPDATE)) {
+			image_type_id = &image->update_image_type_id;
+			if (!fw_accept_os) {
+				/*
+				 * The OS will not be accepting the firmware
+				 * images. Set the accept bit of all the
+				 * images contained in this capsule.
+				 */
+				status = fwu_accept_image(image_type_id,
+							  update_index);
+			} else {
+				status = fwu_clear_accept_image(image_type_id,
+								update_index);
+			}
+			ret = fwu_to_efi_error(status);
+			if (ret != EFI_SUCCESS) {
+				log_err("Unable to %s the accept bit for the image %pUs\n",
+					fw_accept_os ? "clear" : "set",
+					image_type_id);
+				goto out;
+			}
+
+			log_debug("%s the accepted bit for Image %pUs\n",
+				  fw_accept_os ? "Cleared" : "Set",
+				  image_type_id);
+		}
+
 	}
 
 out:
@@ -1103,6 +1289,9 @@ efi_status_t efi_launch_capsules(void)
 	u16 **files;
 	unsigned int nfiles, index, i;
 	efi_status_t ret;
+	bool capsule_update = true;
+	bool update_status = true;
+	bool fw_accept_os = false;
 
 	if (check_run_capsules() != EFI_SUCCESS)
 		return EFI_SUCCESS;
@@ -1130,12 +1319,19 @@ efi_status_t efi_launch_capsules(void)
 		ret = efi_capsule_read_file(files[i], &capsule);
 		if (ret == EFI_SUCCESS) {
 			ret = efi_capsule_update_firmware(capsule);
-			if (ret != EFI_SUCCESS)
+			if (ret != EFI_SUCCESS) {
 				log_err("Applying capsule %ls failed.\n",
 					files[i]);
-			else
+				update_status = false;
+			} else {
 				log_info("Applying capsule %ls succeeded.\n",
 					 files[i]);
+				if (IS_ENABLED(CONFIG_FWU_MULTI_BANK_UPDATE)) {
+					fwu_post_update_checks(capsule,
+							       &fw_accept_os,
+							       &capsule_update);
+				}
+			}
 
 			/* create CapsuleXXXX */
 			set_capsule_result(index, capsule, ret);
@@ -1143,6 +1339,7 @@ efi_status_t efi_launch_capsules(void)
 			free(capsule);
 		} else {
 			log_err("Reading capsule %ls failed\n", files[i]);
+			update_status = false;
 		}
 		/* delete a capsule either in case of success or failure */
 		ret = efi_capsule_delete_file(files[i]);
@@ -1150,8 +1347,17 @@ efi_status_t efi_launch_capsules(void)
 			log_err("Deleting capsule %ls failed\n",
 				files[i]);
 	}
+
 	efi_capsule_scan_done();
 
+	if (IS_ENABLED(CONFIG_FWU_MULTI_BANK_UPDATE)) {
+		if (capsule_update == true && update_status == true) {
+			ret = fwu_post_update_process(fw_accept_os);
+		} else if (capsule_update == true && update_status == false) {
+			log_err("All capsules were not updated. Not updating FWU metadata\n");
+		}
+	}
+
 	for (i = 0; i < nfiles; i++)
 		free(files[i]);
 	free(files);