feat(measured-boot): add measured boot drivers
Introduces core measured boot support, including TPM event log handling,
hashing infrastructure, and event formatting per TCG spec. The driver is
imported from the existing implementation in TF-A.
Signed-off-by: Harrison Mutai <harrison.mutai@arm.com>
Change-Id: Ib2e6a88c86f110f9a6907c3e6dbb0dc736486de9
diff --git a/lib/event_log/event_handoff.c b/lib/event_log/event_handoff.c
new file mode 100644
index 0000000..238ea27
--- /dev/null
+++ b/lib/event_log/event_handoff.c
@@ -0,0 +1,118 @@
+/*
+ * Copyright (c) 2025, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <stddef.h>
+
+#include <common/debug.h>
+#include <drivers/measured_boot/event_log/event_handoff.h>
+
+#include <platform_def.h>
+
+static uint8_t *get_log_ptr(struct transfer_list_entry *te, size_t offset)
+{
+ uint8_t *base_ptr = transfer_list_entry_data(te);
+
+ if (base_ptr == NULL) {
+ return NULL;
+ }
+
+ return base_ptr + offset;
+}
+
+uint8_t *transfer_list_event_log_extend(struct transfer_list_header *tl,
+ size_t req_size, size_t *free)
+{
+ struct transfer_list_entry *existing_entry;
+ struct transfer_list_entry *new_entry;
+ uint8_t *old_data;
+ size_t existing_offset;
+ size_t old_size;
+
+ if (tl == NULL || free == NULL || req_size == 0) {
+ ERROR("Invalid arguments to event log extend.\n");
+ return NULL;
+ }
+
+ existing_entry = transfer_list_find(tl, TL_TAG_TPM_EVLOG);
+ existing_offset = EVENT_LOG_RESERVED_BYTES;
+
+ if (existing_entry != NULL) {
+ existing_offset = existing_entry->data_size;
+
+ if (transfer_list_set_data_size(tl, existing_entry,
+ req_size + existing_offset)) {
+ VERBOSE("TPM event log entry resized: new space %zu bytes at offset %zu\n",
+ req_size, existing_offset);
+
+ *free = existing_entry->data_size - existing_offset;
+
+ return get_log_ptr(existing_entry, existing_offset);
+ }
+ }
+
+ /* Add new entry (resize failed or no existing entry) */
+ new_entry = transfer_list_add(tl, TL_TAG_TPM_EVLOG,
+ req_size + existing_offset, NULL);
+
+ if (new_entry == NULL) {
+ ERROR("Failed to add TPM event log entry to transfer list.\n");
+ return NULL;
+ }
+
+ VERBOSE("New TPM event log entry added at %p\n",
+ transfer_list_entry_data(new_entry));
+
+ if (existing_entry != NULL) {
+ old_data = transfer_list_entry_data(existing_entry);
+ old_size = existing_offset;
+
+ VERBOSE("Copying existing event log (%zu bytes) to new entry at %p\n",
+ old_size, transfer_list_entry_data(new_entry));
+
+ memmove(transfer_list_entry_data(new_entry), old_data,
+ old_size);
+
+ transfer_list_rem(tl, existing_entry);
+ }
+
+ *free = new_entry->data_size - existing_offset;
+
+ return get_log_ptr(new_entry, existing_offset);
+}
+
+uint8_t *transfer_list_event_log_finish(struct transfer_list_header *tl,
+ uintptr_t cursor)
+{
+ uintptr_t entry_data_base;
+ size_t final_log_size;
+ struct transfer_list_entry *entry;
+
+ entry = transfer_list_find(tl, TL_TAG_TPM_EVLOG);
+ entry_data_base = (uintptr_t)transfer_list_entry_data(entry);
+
+ if (cursor < entry_data_base ||
+ cursor >= entry_data_base + entry->data_size) {
+ ERROR("Invalid cursor: outside event log bounds.\n");
+ return NULL;
+ }
+
+ final_log_size = cursor - entry_data_base;
+
+ if (!transfer_list_set_data_size(tl, entry, final_log_size)) {
+ ERROR("Unable to resize event log TE.\n");
+ return NULL;
+ }
+
+ transfer_list_update_checksum(tl);
+
+ VERBOSE("TPM event log finalized: trimmed to %zu bytes",
+ final_log_size - EVENT_LOG_RESERVED_BYTES);
+
+ /* Ensure changes are visible to the next stage. */
+ flush_dcache_range((uintptr_t)tl, tl->size);
+
+ return get_log_ptr(entry, EVENT_LOG_RESERVED_BYTES);
+}