zephyr: Allow enabling logical sectors

Add Kconfigs:
 - CONFIG_MCUBOOT_LOGICAL_SECTOR_SIZE
 - CONFIG_MCUBOOT_LOGICAL_SECTOR_VALIDATION

Signed-off-by: Dominik Ermel <dominik.ermel@nordicsemi.no>

Author: de-nordic

boot/zephyr/Kconfig

@@ -1094,14 +1094,35 @@ config BOOT_FIH_PROFILE_DEFAULT_HIGH
 
 endmenu
 
+config MCUBOOT_LOGICAL_SECTOR_SIZE
+	int "Size of a logical sector"
+	default 0
+	help
+	  Set to 0 to use hardware sectors. Any other value here should be
+	  aligned to hardware sectors in size and alignment.
+
+config MCUBOOT_LOGICAL_SECTOR_SIZE_SET
+	bool
+	default y if MCUBOOT_LOGICAL_SECTOR_SIZE != 0
+
+config MCUBOOT_LOGICAL_SECTOR_VALIDATION
+	bool "Validate logical sector layout"
+	default true if MCUBOOT_LOGICAL_SECTOR_SIZE != 0
+	depends on MCUBOOT_LOGICAL_SECTOR_SIZE_SET
+	help
+	  Validation of logical sector size against hardware constrains.
+	  Should be used to validate compile-time configuration against run-time
+	  system.
+
 config MCUBOOT_DEVICE_SETTINGS
 	# Hidden selector for device-specific settings
 	bool
 	default y
         # CPU options
 	select MCUBOOT_DEVICE_CPU_CORTEX_M0 if CPU_CORTEX_M0
         # Enable flash page layout if available
-	select FLASH_PAGE_LAYOUT if FLASH_HAS_PAGE_LAYOUT
+	select FLASH_PAGE_LAYOUT if FLASH_HAS_PAGE_LAYOUT && !MCUBOOT_LOGICAL_SECTOR_SIZE_SET
+	select FLASH_PAGE_LAYOUT if FLASH_HAS_PAGE_LAYOUT && MCUBOOT_LOGICAL_SECTOR_VALIDATION
 	# Enable flash_map module as flash I/O back-end
 	select FLASH_MAP
 

boot/zephyr/flash_map_extended.c

@@ -65,8 +65,6 @@ BOOT_LOG_MODULE_DECLARE(mcuboot);
 #error "FLASH_DEVICE_ID could not be determined"
 #endif
 
-static const struct device *flash_dev = DEVICE_DT_GET(FLASH_DEVICE_NODE);
-
 int flash_device_base(uint8_t fd_id, uintptr_t *ret)
 {
     if (fd_id != FLASH_DEVICE_ID) {
@@ -156,10 +154,26 @@ int flash_area_id_from_direct_image(int image_id)
 }
 #endif
 
+uint8_t flash_area_get_device_id(const struct flash_area *fa)
+{
+    (void)fa;
+    return FLASH_DEVICE_ID;
+}
+
+#define ERASED_VAL 0xff
+__weak uint8_t flash_area_erased_val(const struct flash_area *fap)
+{
+    (void)fap;
+    return ERASED_VAL;
+}
+
+#if (defined(CONFIG_MCUBOOT_LOGICAL_SECTOR_SIZE) && CONFIG_MCUBOOT_LOGICAL_SECTOR_SIZE == 0) || \
+    defined(CONFIG_MCUBOOT_LOGICAL_SECTOR_VALIDATION)
 int flash_area_sector_from_off(off_t off, struct flash_sector *sector)
 {
     int rc;
     struct flash_pages_info page;
+    static const struct device *flash_dev = DEVICE_DT_GET(FLASH_DEVICE_NODE);
 
     rc = flash_get_page_info_by_offs(flash_dev, off, &page);
     if (rc) {
@@ -172,19 +186,6 @@ int flash_area_sector_from_off(off_t off, struct flash_sector *sector)
     return rc;
 }
 
-uint8_t flash_area_get_device_id(const struct flash_area *fa)
-{
-    (void)fa;
-    return FLASH_DEVICE_ID;
-}
-
-#define ERASED_VAL 0xff
-__weak uint8_t flash_area_erased_val(const struct flash_area *fap)
-{
-    (void)fap;
-    return ERASED_VAL;
-}
-
 int flash_area_get_sector(const struct flash_area *fap, off_t off,
                           struct flash_sector *fsp)
 {
@@ -205,3 +206,27 @@ int flash_area_get_sector(const struct flash_area *fap, off_t off,
 
     return rc;
 }
+#else
+int flash_area_sector_from_off(off_t off, struct flash_sector *sector)
+{
+    sector->fs_off =  off & ~(CONFIG_MCUBOOT_LOGICAL_SECTOR_SIZE - 1);
+    sector->fs_size = CONFIG_MCUBOOT_LOGICAL_SECTOR_SIZE;
+
+    return 0;
+}
+
+int flash_area_get_sector(const struct flash_area *fap, off_t off,
+                          struct flash_sector *fsp)
+{
+    if (off < 0 || (size_t) off >= flash_area_get_size(fap)) {
+	BOOT_LOG_ERR("flash_area_get_sector: off %ld out of area %p",
+                     (long)off, fap);
+        return -ERANGE;
+    }
+
+    fsp->fs_off = off & ~(CONFIG_MCUBOOT_LOGICAL_SECTOR_SIZE - 1);
+    fsp->fs_size = CONFIG_MCUBOOT_LOGICAL_SECTOR_SIZE;
+
+    return 0;
+}
+#endif

boot/zephyr/include/mcuboot_config/mcuboot_config.h

@@ -353,6 +353,27 @@
 #  endif
 #endif
 
+/* If set to non-0 it will use logical sectors rather than querying
+ * device for sector sizes. This slightly reduces code and RAM usage.
+ * Note that the logical sector size has to be multiple of erase
+ * sector size that is biggest for of all devices in the system.
+ */
+#if defined(CONFIG_MCUBOOT_LOGICAL_SECTOR_SIZE)
+#define MCUBOOT_LOGICAL_SECTOR_SIZE		CONFIG_MCUBOOT_LOGICAL_SECTOR_SIZE
+#endif
+
+/* Enable to validate compile time logical sector setup vs the real device layout.
+ * This increases the size of bootloader but is useful to check whether
+ * selected logical sector size can be used with provided partitions
+ * and devices they are placed on.
+ * Once layout is tested, this option should be disabled, for production
+ * devices, as it is pointless to re-validate non-changing setup on
+ * every MCUboot run.
+ */
+#if defined(CONFIG_MCUBOOT_LOGICAL_SECTOR_VALIDATION)
+#define MCUBOOT_LOGICAL_SECTOR_VALIDATION 1
+#endif
+
 #if defined(CONFIG_BOOT_MAX_IMG_SECTORS_AUTO) && defined(MIN_SECTOR_COUNT)
 
 #define MCUBOOT_MAX_IMG_SECTORS       MIN_SECTOR_COUNT