nrf_desktop: Fix checks for the current DFU slot

Allow to start the FW code in the middle of the MCUboot slot.

Signed-off-by: Tomasz Chyrowicz <[email protected]>

Author: tomchy

applications/nrf_desktop/src/modules/dfu.c

@@ -107,9 +107,14 @@ LOG_MODULE_REGISTER(MODULE, CONFIG_DESKTOP_CONFIG_CHANNEL_DFU_LOG_LEVEL);
 		BUILD_ASSERT(DT_FIXED_PARTITION_EXISTS(MCUBOOT_SECONDARY_NODE),
 			     "Missing secondary partition definition in DTS.");
 
+
 		#define CODE_PARTITION_START_ADDR    DT_FIXED_PARTITION_ADDR(CODE_PARTITION_NODE)
 		#define MCUBOOT_PRIMARY_START_ADDR   DT_FIXED_PARTITION_ADDR(MCUBOOT_PRIMARY_NODE)
 		#define MCUBOOT_SECONDARY_START_ADDR DT_FIXED_PARTITION_ADDR(MCUBOOT_SECONDARY_NODE)
+		#define MCUBOOT_PRIMARY_END_ADDR     (MCUBOOT_PRIMARY_START_ADDR + \
+						      DT_REG_SIZE(MCUBOOT_PRIMARY_NODE))
+		#define MCUBOOT_SECONDARY_END_ADDR   (MCUBOOT_SECONDARY_START_ADDR + \
+						      DT_REG_SIZE(MCUBOOT_SECONDARY_NODE))
 
 		#if MCUBOOT_PRIMARY_START_ADDR == MCUBOOT_SECONDARY_START_ADDR
 			#error Primary and secondary partitions cannot have the same address.
@@ -118,9 +123,15 @@ LOG_MODULE_REGISTER(MODULE, CONFIG_DESKTOP_CONFIG_CHANNEL_DFU_LOG_LEVEL);
 		#define MCUBOOT_PRIMARY_SLOT_ID   DT_FIXED_PARTITION_ID(MCUBOOT_PRIMARY_NODE)
 		#define MCUBOOT_SECONDARY_SLOT_ID DT_FIXED_PARTITION_ID(MCUBOOT_SECONDARY_NODE)
 
-		#if CODE_PARTITION_START_ADDR == MCUBOOT_PRIMARY_START_ADDR
+		/* Use range check to allow for placing MCUboot header in a separate partition,
+		 * so the application code partition is not an alias for the MCUboot partition,
+		 * but a subpartition of the MCUboot partition.
+		 */
+		#if (CODE_PARTITION_START_ADDR >= MCUBOOT_PRIMARY_START_ADDR) && \
+		    (CODE_PARTITION_START_ADDR < MCUBOOT_PRIMARY_END_ADDR)
 			#define DFU_SLOT_ID MCUBOOT_SECONDARY_SLOT_ID
-		#elif CODE_PARTITION_START_ADDR == MCUBOOT_SECONDARY_START_ADDR
+		#elif (CODE_PARTITION_START_ADDR >= MCUBOOT_SECONDARY_START_ADDR) && \
+		      (CODE_PARTITION_START_ADDR < MCUBOOT_SECONDARY_END_ADDR)
 			#define DFU_SLOT_ID MCUBOOT_PRIMARY_SLOT_ID
 		#else
 			#error Missing partition definitions in DTS.