PoC: Persistent storage

hw/application_fpga/Makefile

@@ -32,7 +32,7 @@ TARGET_FREQ ?= 21
 
 # Size in 32-bit words, must be divisible by 256 (pairs of EBRs, because 16
 # bits wide; an EBR is 128 32-bits words)
-BRAM_FW_SIZE ?= 1536
+BRAM_FW_SIZE ?= 2048
 
 PIN_FILE ?= application_fpga_tk1.pcf
 
@@ -47,7 +47,7 @@ CFLAGS = \
 	-mabi=ilp32 \
 	-static \
 	-std=gnu99 \
-	-O2 \
+	-Os \
 	-ffast-math \
 	-fno-common \
 	-fno-builtin-printf \
@@ -106,11 +106,21 @@ PICORV32_SRCS = \
 
 FIRMWARE_DEPS = \
 	$(P)/fw/tk1_mem.h \
-	$(P)/fw/tk1/types.h \
 	$(P)/fw/tk1/lib.h \
 	$(P)/fw/tk1/proto.h \
 	$(P)/fw/tk1/assert.h \
-	$(P)/fw/tk1/led.h
+	$(P)/fw/tk1/led.h \
+	$(P)/fw/tk1/blake2s/blake2s.h \
+	$(P)/fw/tk1/spi.h \
+	$(P)/fw/tk1/flash.h \
+	$(P)/fw/tk1/partition_table.h \
+	$(P)/fw/tk1/preload_app.h \
+	$(P)/fw/tk1/auth_app.h \
+	$(P)/fw/tk1/htif.h \
+	$(P)/fw/tk1/rng.h \
+	$(P)/fw/tk1/mgmt_app.h \
+	$(P)/fw/tk1/storage.h \
+	$(P)/fw/tk1/syscall.h
 
 FIRMWARE_OBJS = \
 	$(P)/fw/tk1/main.o \
@@ -119,15 +129,35 @@ FIRMWARE_OBJS = \
 	$(P)/fw/tk1/lib.o \
 	$(P)/fw/tk1/assert.o \
 	$(P)/fw/tk1/led.o \
-	$(P)/fw/tk1/blake2s/blake2s.o
+	$(P)/fw/tk1/blake2s/blake2s.o \
+	$(P)/fw/tk1/spi.o \
+	$(P)/fw/tk1/flash.o \
+	$(P)/fw/tk1/partition_table.o \
+	$(P)/fw/tk1/preload_app.o \
+	$(P)/fw/tk1/auth_app.o \
+	$(P)/fw/tk1/htif.o \
+	$(P)/fw/tk1/rng.o \
+	$(P)/fw/tk1/mgmt_app.o \
+	$(P)/fw/tk1/storage.o \
+	$(P)/fw/tk1/syscall.o
 
 FIRMWARE_SOURCES = \
 	$(P)/fw/tk1/main.c \
 	$(P)/fw/tk1/proto.c \
 	$(P)/fw/tk1/lib.c \
 	$(P)/fw/tk1/assert.c \
 	$(P)/fw/tk1/led.c \
-	$(P)/fw/tk1/blake2s/blake2s.c
+	$(P)/fw/tk1/blake2s/blake2s.c \
+	$(P)/fw/tk1/spi.c \
+	$(P)/fw/tk1/flash.c \
+	$(P)/fw/tk1/partition_table.c \
+	$(P)/fw/tk1/preload_app.c \
+	$(P)/fw/tk1/auth_app.c \
+	$(P)/fw/tk1/htif.c \
+	$(P)/fw/tk1/rng.c \
+	$(P)/fw/tk1/mgmt_app.c \
+	$(P)/fw/tk1/storage.c \
+	$(P)/fw/tk1/syscall.c
 
 TESTFW_OBJS = \
 	$(P)/fw/testfw/main.o \
@@ -168,7 +198,11 @@ secret:
 # Firmware generation.
 # Included in the bitstream.
 #-------------------------------------------------------------------
-LDFLAGS = -T $(P)/fw/tk1/firmware.lds
+# -Wl,-mllvm,-mattr=+c,-mllvm,-mattr=+zmmul added as a workaround to be able to
+#  disassemble compressed RV32 instructions
+LDFLAGS = \
+	-T $(P)/fw/tk1/firmware.lds \
+	-Wl,-mllvm,-mattr=+c,-mllvm,-mattr=+zmmul
 
 $(FIRMWARE_OBJS): $(FIRMWARE_DEPS)
 $(TESTFW_OBJS): $(FIRMWARE_DEPS)
@@ -325,7 +359,7 @@ tb:
 # Synthesis. Place & Route. Bitstream generation.
 #-------------------------------------------------------------------
 
-YOSYS_FLAG ?=
+YOSYS_FLAG ?=-DINCLUDE_SPI_MASTER
 
 synth.json: $(FPGA_SRC) $(VERILOG_SRCS) $(PICORV32_SRCS) bram_fw.hex \
 		$(P)/data/uds.hex $(P)/data/udi.hex

hw/application_fpga/fw/testfw/main.c

@@ -6,9 +6,11 @@
 #include "../tk1/blake2s/blake2s.h"
 #include "../tk1/lib.h"
 #include "../tk1/proto.h"
-#include "../tk1/types.h"
 #include "../tk1_mem.h"
 
+#include <stddef.h>
+#include <stdint.h>
+
 // clang-format off
 volatile uint32_t *tk1name0        = (volatile uint32_t *)TK1_MMIO_TK1_NAME0;
 volatile uint32_t *tk1name1        = (volatile uint32_t *)TK1_MMIO_TK1_NAME1;

hw/application_fpga/fw/tk1/Makefile

@@ -1,5 +1,5 @@
 # Uses ../.clang-format
-FMTFILES=main.c lib.h lib.c proto.h proto.c types.h assert.c assert.h led.c led.h
+FMTFILES=main.c lib.h lib.c proto.h proto.c assert.c assert.h led.c led.h
 .PHONY: fmt
 fmt:
 	clang-format --dry-run --ferror-limit=0 $(FMTFILES)

hw/application_fpga/fw/tk1/assert.c

@@ -4,6 +4,7 @@
  */
 
 #include "assert.h"
+#include "htif.h"
 #include "lib.h"
 
 void assert_fail(const char *assertion, const char *file, unsigned int line,

hw/application_fpga/fw/tk1/auth_app.c

@@ -0,0 +1,68 @@
+// Copyright (C) 2024 - Tillitis AB
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include "auth_app.h"
+#include "../tk1_mem.h"
+#include "blake2s/blake2s.h"
+#include "lib.h"
+#include "partition_table.h"
+#include "rng.h"
+
+#include <stdbool.h>
+#include <stdint.h>
+
+static volatile uint32_t *cdi = (volatile uint32_t *)TK1_MMIO_TK1_CDI_FIRST;
+
+/* Calculates the authentication digest based on a supplied nonce and the CDI.
+ * Requires that the CDI is already calculated and stored */
+static void calculate_auth_digest(uint8_t *nonce, uint8_t *auth_digest)
+{
+	/* TODO: Check so the CDI is non-zero? */
+
+	blake2s_ctx ctx = {0};
+
+	// Generate a 16 byte authentication digest
+	blake2s_init(&ctx, 16, NULL, 0);
+	blake2s_update(&ctx, (const void *)cdi, 32);
+	blake2s_update(&ctx, nonce, 16);
+	blake2s_final(&ctx, auth_digest);
+}
+
+/* Generates a 16 byte nonce */
+static void generate_nonce(uint32_t *nonce)
+{
+
+	for (uint8_t i = 0; i < 4; i++) {
+		nonce[i] = rng_get_word();
+	}
+	return;
+}
+/* Returns the authentication digest and random nonce. Requires that the CDI is
+ * already calculated and stored */
+void auth_app_create(auth_metadata_t *auth_table)
+{
+	uint8_t nonce[16];
+	uint8_t auth_digest[16];
+
+	generate_nonce((uint32_t *)nonce);
+
+	calculate_auth_digest(nonce, auth_digest);
+
+	memcpy_s(auth_table->authentication_digest, 16, auth_digest, 16);
+	memcpy_s(auth_table->nonce, 16, nonce, 16);
+
+	return;
+}
+
+bool auth_app_authenticate(auth_metadata_t *auth_table)
+{
+	uint8_t auth_digest[16];
+
+	calculate_auth_digest(auth_table->nonce, auth_digest);
+
+	if (memeq(auth_digest, auth_table->authentication_digest, 16)) {
+		return true;
+	}
+
+	return false;
+}

hw/application_fpga/fw/tk1/auth_app.h

@@ -0,0 +1,14 @@
+// Copyright (C) 2024 - Tillitis AB
+// SPDX-License-Identifier: GPL-2.0-only
+
+#ifndef AUTH_APP_H
+#define AUTH_APP_H
+
+#include "partition_table.h"
+
+#include <stdbool.h>
+
+void auth_app_create(auth_metadata_t *auth_table);
+bool auth_app_authenticate(auth_metadata_t *auth_table);
+
+#endif

hw/application_fpga/fw/tk1/blake2s/blake2s.c

@@ -6,10 +6,12 @@
 // A simple blake2s Reference Implementation.
 //======================================================================
 
-#include "../types.h"
 #include "../lib.h"
 #include "blake2s.h"
 
+#include <stdint.h>
+#include <stddef.h>
+
 // Dummy printf() for verbose mode
 static void printf(const char *format, ...)
 {

hw/application_fpga/fw/tk1/blake2s/blake2s.h

@@ -4,7 +4,8 @@
 #ifndef BLAKE2S_H
 #define BLAKE2S_H
 
-#include "../types.h"
+#include <stdint.h>
+#include <stddef.h>
 
 // state context
 typedef struct {