1 files changed, 144 insertions, 0 deletions
diff --git a/roms/skiboot/libstb/secvar/secvar_main.c b/roms/skiboot/libstb/secvar/secvar_main.c
new file mode 100644
index 000000000..759d8ef41
--- /dev/null
+++ b/roms/skiboot/libstb/secvar/secvar_main.c
@@ -0,0 +1,144 @@
+// SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+/* Copyright 2019 IBM Corp. */
+
+#ifndef pr_fmt
+#define pr_fmt(fmt) "SECVAR: " fmt
+#endif
+
+#include <stdlib.h>
+#include <skiboot.h>
+#include <opal.h>
+#include <libstb/secureboot.h>
+#include "secvar.h"
+#include "secvar_devtree.h"
+
+struct list_head variable_bank;
+struct list_head update_bank;
+
+int secvar_enabled = 0;	// Set to 1 if secvar is supported
+int secvar_ready = 0;	// Set to 1 when base secvar inits correctly
+
+// To be filled in by platform.secvar_init
+struct secvar_storage_driver secvar_storage = {0};
+struct secvar_backend_driver secvar_backend = {0};
+
+
+int secvar_main(struct secvar_storage_driver storage_driver,
+               struct secvar_backend_driver backend_driver)
+{
+	int rc = OPAL_UNSUPPORTED;
+
+	prlog(PR_INFO, "Secure variables are supported, initializing secvar\n");
+
+	secvar_storage = storage_driver;
+	secvar_backend = backend_driver;
+
+	secvar_init_devnode(secvar_backend.compatible);
+
+	secvar_enabled = 1;
+
+	list_head_init(&variable_bank);
+	list_head_init(&update_bank);
+
+	/*
+	 * Failures here should indicate some kind of hardware problem,
+	 * therefore we don't even attempt to continue
+	 */
+	rc = secvar_storage.store_init();
+	if (rc)
+		secureboot_enforce();
+
+	rc = secvar_storage.load_bank(&variable_bank, SECVAR_VARIABLE_BANK);
+	if (rc)
+		goto fail;
+
+	rc = secvar_storage.load_bank(&update_bank, SECVAR_UPDATE_BANK);
+	if (rc)
+		goto fail;
+
+	/*
+	 * At this point, base secvar is functional.
+	 * In the event of some error, boot up to Petitboot in secure mode
+	 * with an empty keyring, for an admin to attempt to debug.
+	 */
+	secvar_ready = 1;
+	secvar_set_status("okay");
+
+	if (secvar_backend.pre_process) {
+		rc = secvar_backend.pre_process(&variable_bank, &update_bank);
+		if (rc) {
+			prlog(PR_ERR, "Error in backend pre_process = %d\n", rc);
+			/* Early failure state, lock the storage */
+			secvar_storage.lockdown();
+			goto soft_fail;
+		}
+	}
+
+	// Process is required, error if it doesn't exist
+	if (!secvar_backend.process)
+		goto soft_fail;
+
+	/* Process variable updates from the update bank. */
+	rc = secvar_backend.process(&variable_bank, &update_bank);
+
+	/* Create and set the update-status device tree property */
+	secvar_set_update_status(rc);
+
+	/*
+	 * Only write to the storage if we actually processed updates
+	 * OPAL_EMPTY implies no updates were processed
+	 * Refer to full table in doc/device-tree/ibm,opal/secvar.rst
+	 */
+	if (rc == OPAL_SUCCESS) {
+		rc = secvar_storage.write_bank(&variable_bank, SECVAR_VARIABLE_BANK);
+		if (rc)
+			goto soft_fail;
+	}
+	/*
+	 * Write (and probably clear) the update bank if .process() actually detected
+	 * and handled updates in the update bank. Unlike above, this includes error
+	 * cases, where the backend should probably be clearing the bank.
+	 */
+	if (rc != OPAL_EMPTY) {
+		rc = secvar_storage.write_bank(&update_bank,
+					       SECVAR_UPDATE_BANK);
+		if (rc)
+			goto soft_fail;
+	}
+	/* Unconditionally lock the storage at this point */
+	secvar_storage.lockdown();
+
+	if (secvar_backend.post_process) {
+		rc = secvar_backend.post_process(&variable_bank, &update_bank);
+		if (rc) {
+			prlog(PR_ERR, "Error in backend post_process = %d\n", rc);
+			goto soft_fail;
+		}
+	}
+
+	prlog(PR_INFO, "secvar initialized successfully\n");
+
+	return OPAL_SUCCESS;
+
+fail:
+	/* Early failure, base secvar support failed to initialize */
+	secvar_set_status("fail");
+	secvar_storage.lockdown();
+	secvar_set_secure_mode();
+
+	prerror("secvar failed to initialize, rc = %04x\n", rc);
+	return rc;
+
+soft_fail:
+	/*
+	 * Soft-failure, enforce secure boot with an empty keyring in
+	 * bootloader for debug/recovery
+	 */
+	clear_bank_list(&variable_bank);
+	clear_bank_list(&update_bank);
+	secvar_storage.lockdown();
+	secvar_set_secure_mode();
+
+	prerror("secvar failed to initialize, rc = %04x\n", rc);
+	return rc;
+}