Added SWAP=0 option, fixed some warnings

Makefile

@@ -11,6 +11,7 @@ SIGN?=ED25519
 TARGET?=stm32f4
 DEBUG?=0
 VTOR?=1
+SWAP?=1
 
 LSCRIPT:=hal/$(TARGET).ld
 
@@ -60,6 +61,9 @@ ifeq ($(VTOR),0)
     CFLAGS+=-DNO_VTOR
 endif
 
+ifeq ($(SWAP),0)
+    CFLAGS+=-DWOLFBOOT_OVERWRITE_ONLY
+endif
 
 
 LDFLAGS:=-T $(LSCRIPT) -Wl,-gc-sections -Wl,-Map=wolfboot.map -ffreestanding -nostartfiles -mcpu=cortex-m3 -mthumb -nostdlib

hal/nrf52.c

@@ -54,7 +54,6 @@ static void flash_wait_complete(void)
 int hal_flash_write(uint32_t address, const uint8_t *data, int len)
 {
     int i;
-    uint32_t val;
     NVMC_CONFIG = NVMC_CONFIG_WEN;
     flash_wait_complete();
     /* Set 8-bit write */

include/target.h

@@ -4,6 +4,10 @@
 #define FLASH_DEV_NAME			"flash"
 #define FLASH_ALIGN			4
 
+/* Example flash partitioning.
+ * Ensure that your firmware entry point is
+ * at FLASH_AREA_IMAGE_0_OFFSET + 0x100
+ */
 #define FLASH_AREA_IMAGE_0_OFFSET	0x20000
 #define FLASH_AREA_IMAGE_0_SIZE		0x20000
 #define FLASH_AREA_IMAGE_1_OFFSET	0x40000
@@ -19,9 +23,7 @@
     !defined(FLASH_AREA_IMAGE_0_OFFSET) || \
     !defined(FLASH_AREA_IMAGE_0_SIZE) || \
     !defined(FLASH_AREA_IMAGE_1_OFFSET) || \
-    !defined(FLASH_AREA_IMAGE_1_SIZE) || \
-    !defined(FLASH_AREA_IMAGE_SCRATCH_OFFSET) || \
-    !defined(FLASH_AREA_IMAGE_SCRATCH_SIZE)
+    !defined(FLASH_AREA_IMAGE_1_SIZE) 
 #error "Target support is incomplete; cannot build wolfboot."
 #endif
 

lib/bootutil/src/loader.c

@@ -1332,9 +1332,11 @@ boot_go(struct boot_rsp *rsp)
         rc = flash_area_open(fa_id, &BOOT_IMG_AREA(&boot_data, slot));
         assert(rc == 0);
     }
+#ifndef WOLFBOOT_OVERWRITE_ONLY 
     rc = flash_area_open(FLASH_AREA_IMAGE_SCRATCH,
                          &BOOT_SCRATCH_AREA(&boot_data));
     assert(rc == 0);
+#endif
 
     /* Determine the sector layout of the image slots and scratch area. */
     rc = boot_read_sectors();

src/run.c

@@ -75,6 +75,7 @@ static struct area_desc flash_areas[1] = {
                 .id = FLASH_AREA_IMAGE_1,
                 .num_areas = 1
             },
+#ifndef WOLFBOOT_OVERWRITE_ONLY 
             {
                 .whole = {
                     .fa_id = FLASH_AREA_IMAGE_SCRATCH,
@@ -87,6 +88,10 @@ static struct area_desc flash_areas[1] = {
             }
         },
         .num_slots = 3
+#else
+        },
+        .num_slots = 2
+#endif
     }
 } ;
 
@@ -144,7 +149,6 @@ int flash_area_read(const struct flash_area *area, uint32_t off, void *dst,
 int flash_area_write(const struct flash_area *area, uint32_t off, const void *src,
                      uint32_t len)
 {
-    uint32_t address;
     BOOT_LOG_DBG("%s: area=%d, off=%x, len=%x", __func__,
                  area->fa_id, off, len);
     hal_flash_unlock();