Add start of pre-loaded app from flash

Based on earlier code by Daniel Jobson <jobson@tillitis.se> now
integrated into the new world order.

Co-authored-by: Mikael Ågren <mikael@tillitis.se>
Co-authored-by: Daniel Jobson <jobson@tillitis.se>

hw/application_fpga/fw/tk1/preload_app.c

@@ -0,0 +1,139 @@
+// Copyright (C) 2024 - Tillitis AB
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <tkey/debug.h>
+#include <tkey/lib.h>
+#include <tkey/tk1_mem.h>
+
+#include "flash.h"
+#include "mgmt_app.h"
+#include "partition_table.h"
+#include "preload_app.h"
+
+/* Returns non-zero if the app is valid */
+bool preload_check_valid_app(struct partition_table *part_table)
+{
+
+	if (part_table->pre_app_data.status == 0x00 &&
+	    part_table->pre_app_data.size == 0) {
+		/*No valid app*/
+		return false;
+	}
+
+	return true;
+}
+
+/* Loads a preloaded app from flash to app RAM */
+int preload_load(struct partition_table *part_table)
+{
+	/*Check for a valid app in flash	*/
+	if (!preload_check_valid_app(part_table)) {
+		return -1;
+	}
+	uint8_t *loadaddr = (uint8_t *)TK1_RAM_BASE;
+
+	/* Read from flash, straight into RAM */
+	int ret = flash_read_data(ADDR_PRE_LOADED_APP, loadaddr,
+				  part_table->pre_app_data.size);
+
+	return ret;
+}
+
+/* Expects to receive chunks of data up to 4096 bytes to store into the
+ * preloaded area. The offset needs to be kept and updated between each call.
+ * Once done, call preload_store_finalize() with the last parameters.
+ * */
+int preload_store(struct partition_table *part_table, uint32_t offset,
+		  uint8_t *data, size_t size)
+{
+	/* Check if we are allowed to store */
+	if (!mgmt_app_authenticate(&part_table->mgmt_app_data)) {
+		return -3;
+	}
+
+	/* Check for a valid app in flash, bale out if it already exists */
+	if (preload_check_valid_app(part_table)) {
+		return -1;
+	}
+
+	if ((offset + size) > SIZE_PRE_LOADED_APP || size > 4096) {
+		/* Writing outside of area */
+		return -2;
+	}
+
+	uint32_t address = ADDR_PRE_LOADED_APP + offset;
+
+	debug_puts("preload_store: write to addr: ");
+	debug_putinthex(address);
+	debug_lf();
+
+	return flash_write_data(address, data, size);
+}
+
+int preload_store_finalize(struct partition_table *part_table, bool use_uss,
+			   uint8_t *uss, size_t app_size)
+{
+	/* Check if we are allowed to store */
+	if (!mgmt_app_authenticate(&part_table->mgmt_app_data)) {
+		return -3;
+	}
+
+	/* Check for a valid app in flash, bale out if it already exists */
+	if (preload_check_valid_app(part_table)) {
+		return -1;
+	}
+
+	// TODO: Maybe add the uss fields
+
+	if (app_size == 0 || app_size > SIZE_PRE_LOADED_APP) {
+		return -2;
+	}
+
+	part_table->pre_app_data.size = app_size;
+	part_table->pre_app_data.status =
+	    0x02; /* Stored but not yet authenticated */
+	debug_puts("preload_*_final: size: ");
+	debug_putinthex(app_size);
+	debug_lf();
+
+	part_table_write(part_table);
+
+	/* Force a restart to authenticate the stored app */
+	/* TODO: Should this be done by the management app or by firmware? */
+
+	return 0;
+}
+
+int preload_delete(struct partition_table *part_table)
+{
+	/* Check if we are allowed to deleted */
+	if (!mgmt_app_authenticate(&part_table->mgmt_app_data)) {
+		return -3;
+	}
+
+	/*Check for a valid app in flash	*/
+	if (!preload_check_valid_app(part_table)) {
+		return 0;
+		// TODO: Nothing here, return zero like all is good?
+	}
+	part_table->pre_app_data.size = 0;
+	part_table->pre_app_data.status = 0;
+
+	memset(part_table->pre_app_data.auth.nonce, 0x00,
+	       sizeof(part_table->pre_app_data.auth.nonce));
+
+	memset(part_table->pre_app_data.auth.authentication_digest, 0x00,
+	       sizeof(part_table->pre_app_data.auth.authentication_digest));
+
+	part_table_write(part_table);
+
+	/* Assumes the area is 64 KiB block aligned */
+	flash_block_64_erase(ADDR_PRE_LOADED_APP); // Erase first 64 KB block
+	flash_block_64_erase(ADDR_PRE_LOADED_APP +
+			     0x10000); // Erase second 64 KB block
+
+	return 0;
+}