[nrf fromtree] boot: bootutil: loader: Let image version comparison

... use build number

Change allows using build number in image version comparison.

Signed-off-by: Marek Pieta <Marek.Pieta@nordicsemi.no>
(cherry picked from commit a95a41b)
Signed-off-by: Dominik Ermel <dominik.ermel@nordicsemi.no>

boot/bootutil/src/loader.c

@@ -635,15 +635,17 @@ boot_check_header_erased(struct boot_loader_state *state, int slot)
     defined(MCUBOOT_RAM_LOAD) || \
     defined(MCUBOOT_DOWNGRADE_PREVENTION)
 /**
- * Compare image version numbers not including the build number
+ * Compare image version numbers
+ *
+ * By default, the comparison does not take build number into account.
+ * Enable MCUBOOT_VERSION_CMP_USE_BUILD_NUMBER to take the build number into account.
  *
  * @param ver1           Pointer to the first image version to compare.
  * @param ver2           Pointer to the second image version to compare.
  *
- * @retval -1           If ver1 is strictly less than ver2.
- * @retval 0            If the image version numbers are equal,
- *                      (not including the build number).
- * @retval 1            If ver1 is strictly greater than ver2.
+ * @retval -1           If ver1 is less than ver2.
+ * @retval 0            If the image version numbers are equal.
+ * @retval 1            If ver1 is greater than ver2.
  */
 static int
 boot_version_cmp(const struct image_version *ver1,
@@ -670,6 +672,16 @@ boot_version_cmp(const struct image_version *ver1,
         return -1;
     }
 
+#if defined(MCUBOOT_VERSION_CMP_USE_BUILD_NUMBER)
+    /* The revisions are equal, continue comparison. */
+    if (ver1->iv_build_num > ver2->iv_build_num) {
+        return 1;
+    }
+    if (ver1->iv_build_num < ver2->iv_build_num) {
+        return -1;
+    }
+#endif
+
     return 0;
 }
 #endif

boot/zephyr/Kconfig

@@ -524,6 +524,15 @@ config UPDATEABLE_IMAGE_NUMBER
 	help
 	  Enables support of multi image update.
 
+config BOOT_VERSION_CMP_USE_BUILD_NUMBER
+	bool "Use build number while comparing image version"
+	depends on (UPDATEABLE_IMAGE_NUMBER > 1) || BOOT_DIRECT_XIP || \
+		   BOOT_RAM_LOAD || MCUBOOT_DOWNGRADE_PREVENTION
+	help
+	  By default, the image version comparison relies only on version major,
+	  minor and revision. Enable this option to take into account the build
+	  number as well.
+
 choice BOOT_DOWNGRADE_PREVENTION_CHOICE
 	prompt "Downgrade prevention"
 	optional

boot/zephyr/include/mcuboot_config/mcuboot_config.h

@@ -92,6 +92,10 @@
 #define MCUBOOT_IMAGE_NUMBER    1
 #endif
 
+#ifdef CONFIG_BOOT_VERSION_CMP_USE_BUILD_NUMBER
+#define MCUBOOT_VERSION_CMP_USE_BUILD_NUMBER
+#endif
+
 #ifdef CONFIG_BOOT_SWAP_SAVE_ENCTLV
 #define MCUBOOT_SWAP_SAVE_ENCTLV 1
 #endif