feature: simulated target

This commit introduces a simulated target where the internal and optionally the
external flash can be simulated and backed by files. Using this target will
produce an executable wolfBoot ELF image.

.gitignore

@@ -110,3 +110,6 @@ IDE/IAR/settings
 IDE/IAR/*.ewt
 IDE/IAR/Debug
 IDE/IAR/Release
+
+# Simulated Flash files
+*.dd

Makefile

@@ -69,6 +69,10 @@ ifeq ($(TARGET),library)
 	MAIN_TARGET:=test-lib
 endif
 
+ifeq ($(TARGET),sim)
+	MAIN_TARGET:=wolfboot.elf test-app/image_v1_signed.bin internal_flash.dd
+endif
+
 ASFLAGS:=$(CFLAGS)
 BOOTLOADER_PARTITION_SIZE?=$$(( $(WOLFBOOT_PARTITION_BOOT_ADDRESS) - $(ARCH_FLASH_OFFSET)))
 
@@ -130,10 +134,21 @@ keytools:
 	@make -C tools/keytools clean
 	@make -C tools/keytools
 
-test-app/image_v1_signed.bin: test-app/image.bin
+test-app/image_v1_signed.bin: $(BOOT_IMG)
 	@echo "\t[SIGN] $(BOOT_IMG)"
 	$(Q)$(SIGN_TOOL) $(SIGN_OPTIONS) $(BOOT_IMG) $(PRIVATE_KEY) 1
 
+test-app/image.elf: wolfboot.elf
+	$(Q)$(MAKE) -C test-app WOLFBOOT_ROOT=$(WOLFBOOT_ROOT) image.elf
+	$(Q)$(SIZE) test-app/image.elf
+
+internal_flash.dd: test-app/image_v1_signed.bin wolfboot.elf $(BINASSEMBLE)
+	@echo "\t[MERGE] internal_flash.dd"
+	$(Q)dd if=/dev/zero bs=1 count=$$(($(WOLFBOOT_SECTOR_SIZE))) > /tmp/swap
+	$(Q)$(BINASSEMBLE) $@ 0 test-app/image_v1_signed.bin \
+		$(WOLFBOOT_PARTITION_SIZE) /tmp/swap \
+		$$(($(WOLFBOOT_PARTITION_SIZE)*2)) /tmp/swap
+
 factory.bin: $(BOOT_IMG) wolfboot.bin $(PRIVATE_KEY) test-app/image_v1_signed.bin $(BINASSEMBLE)
 	@echo "\t[MERGE] $@"
 	$(Q)$(BINASSEMBLE) $@ $(ARCH_FLASH_OFFSET) wolfboot.bin \

arch.mk

@@ -368,6 +368,15 @@ ifeq ($(TARGET),x86_64_efi)
   UPDATE_OBJS:=src/update_ram.o
 endif
 
+ifeq ($(TARGET),sim)
+  USE_GCC_HEADLESS=0
+  LD = gcc
+  UPDATE_OBJS:=src/update_flash.o
+  LD_START_GROUP=
+  LD_END_GROUP=
+  BOOT_IMG=test-app/image.elf
+endif
+
 BOOT_IMG?=test-app/image.bin
 
 ## Update mechanism

config/examples/sim.config

@@ -0,0 +1,16 @@
+ARCH=sim
+TARGET=sim
+SIGN?=ED25519
+HASH?=SHA256
+WOLFBOOT_SMALL_STACK=1
+SPI_FLASH=0
+DEBUG=1
+# it should be multiple of system page size
+WOLFBOOT_PARTITION_SIZE=0x2A000
+WOLFBOOT_SECTOR_SIZE=0x1000
+WOLFBOOT_PARTITION_BOOT_ADDRESS=0x10000
+# if on external flash, it should be multiple of system page size
+WOLFBOOT_PARTITION_UPDATE_ADDRESS=0x3a000
+WOLFBOOT_PARTITION_SWAP_ADDRESS=0x64000
+# required for keytools
+WOLFBOOT_FIXED_PARTITIONS=1

docs/Targets.md

@@ -1136,3 +1136,31 @@ Example of flash memory layout and configuration on the nRF52:
 #define WOLFBOOT_PARTITION_SWAP_ADDRESS   0x57000
 #define WOLFBOOT_PARTITION_UPDATE_ADDRESS 0x58000
 ```
+## Simulated
+
+You can create a simulated target that uses files to mimic an internal and
+optionally an external flash. The build will produce an executable ELF file
+`wolfBoot.elf`. You can provide another executable ELF as firmware image and it
+will be executed. The command-line arguments of `wolfBoot.elf` are forwarded to
+the application. The example application `test-app\app_sim.c` uses the arguments
+to interact with `libwolfboot.c` and automatize functional testing.  You can
+find an example configuration in `config/examples/sim.config`.
+
+An example of using the `test-app/sim.c` to test firmware update:
+
+```
+cp ./config/examples/sim.config .config
+make
+
+# create the file internal_flash.dd with firmware v1 on the boot partition and
+# firmware v2 on the update partition
+make test-sim-internal-flash-with-update
+# it should print 1
+./wolfboot.elf success get_version
+# trigger an update
+./wolfboot.elf update_trigger
+# it should print 2
+./wolfboot.elf success get_version
+# it should print 2
+./wolfboot.elf success get_version
+```

hal/sim.c

@@ -0,0 +1,194 @@
+/* sim.c
+ *
+ * Copyright (C) 2022 wolfSSL Inc.
+ *
+ * This file is part of wolfBoot.
+ *
+ * wolfBoot is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * wolfBoot is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
+ */
+
+#define _GNU_SOURCE
+#include <stdint.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "wolfboot/wolfboot.h"
+#include "target.h"
+
+static uint8_t *ram_base;
+static uint8_t *flash_base;
+
+#define INTERNAL_FLASH_FILE "./internal_flash.dd"
+#define EXTERNAL_FLASH_FILE "./external_flash.dd"
+
+/* global used to store command line arguments to forward to the test
+ * application */
+char **main_argv;
+int main_argc;
+
+static int mmap_file(const char *path, uint8_t *address, uint8_t** ret_address)
+{
+    struct stat st = { 0 };
+    uint8_t *mmaped_addr;
+    int ret;
+    int fd;
+
+    if (path == NULL)
+        return -1;
+
+    ret = stat(path, &st);
+    if (ret == -1)
+        return -1;
+
+    fd = open(path, O_RDWR);
+    if (fd == -1) {
+        printf("can't open %s\n", path);
+        return -1;
+    }
+
+    mmaped_addr = mmap(address, st.st_size, PROT_READ | PROT_WRITE,
+                       MAP_SHARED, fd, 0);
+    if (mmaped_addr == MAP_FAILED)
+        return -1;
+
+    if (address != NULL && mmaped_addr != address) {
+        munmap(address, st.st_size);
+        return -1;
+    }
+
+    *ret_address = mmaped_addr;
+
+    close(fd);
+    return 0;
+}
+
+void hal_flash_unlock(void)
+{
+    /* no op */
+}
+
+void hal_flash_lock(void)
+{
+    /* no op */
+}
+
+void hal_prepare_boot(void)
+{
+    /* no op */
+}
+
+int hal_flash_write(uint32_t address, const uint8_t *data, int len)
+{
+    uint8_t *ptr = 0;
+
+    /* implicit cast abide compiler warning */
+    memcpy(ptr + address, data, len);
+    return 0;
+}
+
+int hal_flash_erase(uint32_t address, int len)
+{
+    uint8_t *ptr = 0;
+
+    /* implicit cast abide compiler warning */
+    memset(ptr + address, 0xff, len);
+    return 0;
+}
+
+void hal_init(void)
+{
+    int ret;
+    uint8_t *p;
+    ret = mmap_file(INTERNAL_FLASH_FILE,
+                    (uint8_t*)WOLFBOOT_PARTITION_BOOT_ADDRESS, &p);
+    if (ret != 0) {
+        printf("failed to load internal flash file\n");
+        exit(-1);
+    }
+
+#ifdef EXT_FLASH
+    ret = mmap_file(EXTERNAL_FLASH_FILE, NULL, &flash_base);
+    if (ret != 0) {
+        printf("failed to load internal flash file\n");
+        exit(-1);
+    }
+#endif /* EXT_FLASH */
+}
+
+void ext_flash_lock(void)
+{
+    /* no op */
+}
+
+void ext_flash_unlock(void)
+{
+    /* no op */
+}
+
+int  ext_flash_write(uintptr_t address, const uint8_t *data, int len)
+{
+    memcpy(flash_base + address, data, len);
+    return 0;
+}
+
+int ext_flash_read(uintptr_t address, uint8_t *data, int len)
+{
+    memcpy(data, flash_base + address, len);
+    return len;
+}
+
+int  ext_flash_erase(uintptr_t address, int len)
+{
+    memset(flash_base + address, 0xff, len);
+    return 0;
+}
+
+void do_boot(const uint32_t *app_offset)
+{
+    char *envp[1] = {NULL};
+    int ret;
+    int fd;
+
+    fd = memfd_create("test_app", 0);
+    if (fd == -1) {
+        printf("memfd error\n");
+        exit(-1);
+    }
+
+    ret = write(fd, app_offset, WOLFBOOT_PARTITION_SIZE);
+    if (ret != WOLFBOOT_PARTITION_SIZE) {
+        printf("can't write test-app to memfd\n");
+        exit(-1);
+    }
+
+    ret = fexecve(fd, main_argv, envp);
+    printf("fexecve error\n");
+    exit(1);
+}
+
+int wolfBoot_fallback_is_possible(void)
+{
+    return 0;
+}
+
+int wolfBoot_dualboot_candidate(void)
+{
+    return 0;
+}

hal/sim.ld

@@ -0,0 +1 @@
+# abide Makefile

src/loader.c

@@ -32,8 +32,22 @@ static volatile const uint32_t __attribute__((used)) wolfboot_version = WOLFBOOT
 extern void (** const IV_RAM)(void);
 #endif
 
+#ifdef PLATFORM_sim
+extern char **main_argv;
+extern int main_argc;
+int main(int argc, char *argv[])
+#else
 int main(void)
+#endif
 {
+
+#ifdef PLATFORM_sim
+    /* to forward arguments to the test-app for testing. See
+     * test-app/app_sim.c */
+    main_argv = argv;
+    main_argc = argc;
+#endif
+
     hal_init();
     spi_flash_probe();
 #ifdef UART_FLASH

test-app/Makefile

@@ -6,6 +6,11 @@ TARGET?=none
 ARCH?=ARM
 MCUXPRESSO_CMSIS?=$(MCUXPRESSO)/CMSIS
 
+
+ifeq ($(TARGET),sim)
+  LDFLAGS=-Wl,-gc-sections -Wl,-Map=image.map
+endif
+
 ifeq ($(SIGN),RSA2048)
   IMAGE_HEADER_SIZE:=512
 endif
@@ -117,6 +122,11 @@ else
   LDFLAGS+=-T $(LSCRIPT) -Wl,-gc-sections -Wl,-Map=image.map
 endif
 
+ifeq ($(TARGET),sim)
+  LDFLAGS=-Wl,-gc-sections -Wl,-Map=image.map
+  APP_OBJS=app_$(TARGET).o ../src/libwolfboot.o ../hal/$(TARGET).o
+endif
+
 ifeq ($(EXT_FLASH),1)
   CFLAGS+=-D"EXT_FLASH=1" -D"PART_UPDATE_EXT=1"
 endif

test-app/app_sim.c

@@ -0,0 +1,75 @@
+/* app_sim.c
+ *
+ * Test bare-metal boot-led-on application
+ *
+ * Copyright (C) 2022 wolfSSL Inc.
+ *
+ * This file is part of wolfBoot.
+ *
+ * wolfBoot is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * wolfBoot is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
+ */
+
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include "wolfboot/wolfboot.h"
+
+#ifdef PLATFORM_sim
+
+void hal_init(void);
+
+int do_cmd(const char *cmd)
+{
+    if (strcmp(cmd, "get_version") == 0) {
+        printf("%d", wolfBoot_current_firmware_version());
+        return 0;
+    }
+
+    if (strcmp(cmd, "success") == 0) {
+        wolfBoot_success();
+        return 0;
+    }
+
+    if (strcmp(cmd, "update_trigger") == 0) {
+        wolfBoot_update_trigger();
+        return 0;
+    }
+
+    if (strcmp(cmd, "reset") == 0) {
+        exit(0);
+    }
+
+    /* wrong command */
+    return -1;
+}
+
+int main(int argc, char *argv[]) {
+
+    int i;
+
+    hal_init();
+
+    for (i = 1; i < argc; ++i) {
+        if (do_cmd(argv[i]) != 0)
+            return -1;
+    }
+
+    return 0;
+
+}
+#endif /** PLATFROM_sim **/

test-app/sim.ld

@@ -0,0 +1 @@
+# abide Makefile