bootloader: make bootloader offset address in flash configurable

components/bootloader/CMakeLists.txt

@@ -13,9 +13,9 @@ if(NOT CONFIG_SECURE_BOOT)
 endif()
 
 esptool_py_custom_target(bootloader-flash bootloader "bootloader")
-esptool_py_flash_target_image(bootloader-flash bootloader "0x1000" "${BOOTLOADER_BUILD_DIR}/bootloader.bin")
+esptool_py_flash_target_image(bootloader-flash bootloader ${CONFIG_BOOTLOADER_OFFSET_IN_FLASH} "${BOOTLOADER_BUILD_DIR}/bootloader.bin")
 
 # Also attach an image to the project flash target
 if(NOT CONFIG_SECURE_BOOT)
-    esptool_py_flash_target_image(flash bootloader "0x1000" "${BOOTLOADER_BUILD_DIR}/bootloader.bin")
+    esptool_py_flash_target_image(flash bootloader ${CONFIG_BOOTLOADER_OFFSET_IN_FLASH} "${BOOTLOADER_BUILD_DIR}/bootloader.bin")
 endif()

components/bootloader/Kconfig.projbuild

@@ -1,5 +1,14 @@
 menu "Bootloader config"
 
+    config BOOTLOADER_OFFSET_IN_FLASH
+        hex
+        default 0x1000 if IDF_TARGET_ESP32 || IDF_TARGET_ESP32S2
+        default 0x0
+        help
+            Offset address that 2nd bootloader will be flashed to.
+            The value is determined by the ROM bootloader.
+            It's not configurable in ESP-IDF.
+
     choice BOOTLOADER_COMPILER_OPTIMIZATION
         prompt "Bootloader optimization Level"
         default BOOTLOADER_COMPILER_OPTIMIZATION_SIZE

components/bootloader/project_include.cmake

@@ -1,4 +1,4 @@
-set(BOOTLOADER_OFFSET 0x1000)
+set(BOOTLOADER_OFFSET CONFIG_BOOTLOADER_OFFSET_IN_FLASH)
 
 # Do not generate flash file when building bootloader
 if(BOOTLOADER_BUILD OR NOT CONFIG_APP_BUILD_BOOTLOADER)

components/bootloader_support/include/esp_flash_partitions.h

@@ -44,7 +44,7 @@ extern "C" {
 
 /* Pre-partition table fixed flash offsets */
 #define ESP_BOOTLOADER_DIGEST_OFFSET 0x0
-#define ESP_BOOTLOADER_OFFSET 0x1000 /* Offset of bootloader image. Has matching value in bootloader KConfig.projbuild file. */
+#define ESP_BOOTLOADER_OFFSET CONFIG_BOOTLOADER_OFFSET_IN_FLASH  /* Offset of bootloader image. Has matching value in bootloader KConfig.projbuild file. */
 #define ESP_PARTITION_TABLE_OFFSET CONFIG_PARTITION_TABLE_OFFSET /* Offset of partition table. Backwards-compatible name.*/
 
 #define ESP_PARTITION_TABLE_MAX_LEN 0xC00 /* Maximum length of partition table data */