revert: replace in-tree Event Log Lib w/ submodule

This reverts commit cc89c2fc40c74ea8d8f1a1489ea988c66c1b5849.

Reason for revert: Causing CI failures

Change-Id: Iad32fb9ba1d32044ef647f01e3091e9b0ee0d9e2
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);
+}