dfu: flash_img: add flash_img_get_upload_slot()

add flash_img_get_upload_slot() to get current
upload slot.
when CONFIG_MCUBOOT_BOOTLOADER_MODE_RAM_LOAD
is enabled, it is not based on the DT.

Signed-off-by: Fin Maaß <f.maass@vogl-electronic.com>

include/zephyr/dfu/flash_img.h

@@ -111,6 +111,13 @@ int flash_img_check(struct flash_img_context *ctx,
 		    const struct flash_img_check *fic,
 		    uint8_t area_id);
 
+/**
+ * @brief Get the flash area id for the image upload slot.
+ *
+ * @return flash area id for the image upload slot
+ */
+uint8_t flash_img_get_upload_slot(void);
+
 #ifdef __cplusplus
 }
 #endif

include/zephyr/dfu/mcuboot.h

@@ -159,6 +159,13 @@ int boot_read_bank_header(uint8_t area_id,
 			  struct mcuboot_img_header *header,
 			  size_t header_size);
 
+/**
+ * @brief Get the flash area id for the active image slot.
+ *
+ * @return flash area id for the active image slot
+ */
+uint8_t boot_fetch_active_slot(void);
+
 /**
  * @brief Check if the currently running image is confirmed as OK.
  *

subsys/dfu/boot/mcuboot.c

@@ -44,7 +44,6 @@ LOG_MODULE_REGISTER(mcuboot_dfu, LOG_LEVEL_DBG);
 
 #if defined(CONFIG_MCUBOOT_BOOTLOADER_MODE_RAM_LOAD)
 /* For RAM LOAD mode, the active image must be fetched from the bootloader */
-static uint8_t boot_fetch_active_slot(void);
 #define ACTIVE_SLOT_FLASH_AREA_ID boot_fetch_active_slot()
 #define INVALID_SLOT_ID 255
 #else
@@ -76,7 +75,7 @@ struct mcuboot_v1_raw_header {
  */
 
 #if defined(CONFIG_MCUBOOT_BOOTLOADER_MODE_RAM_LOAD)
-static uint8_t boot_fetch_active_slot(void)
+uint8_t boot_fetch_active_slot(void)
 {
 	int rc;
 	uint8_t slot;
@@ -93,7 +92,12 @@ static uint8_t boot_fetch_active_slot(void)
 
 	return slot;
 }
-#endif
+#else  /* CONFIG_MCUBOOT_BOOTLOADER_MODE_RAM_LOAD */
+uint8_t boot_fetch_active_slot(void)
+{
+	return ACTIVE_SLOT_FLASH_AREA_ID;
+}
+#endif /* CONFIG_MCUBOOT_BOOTLOADER_MODE_RAM_LOAD */
 
 static int boot_read_v1_header(uint8_t area_id,
 			       struct mcuboot_v1_raw_header *v1_raw)

subsys/dfu/img_util/flash_img.c

@@ -10,12 +10,12 @@
 #include <stdio.h>
 #include <string.h>
 #include <zephyr/dfu/flash_img.h>
+#include <zephyr/dfu/mcuboot.h>
 #include <zephyr/storage/flash_map.h>
 #include <zephyr/storage/stream_flash.h>
 
 #ifdef CONFIG_IMG_ERASE_PROGRESSIVELY
 #include <bootutil/bootutil_public.h>
-#include <zephyr/dfu/mcuboot.h>
 #endif
 
 #include <zephyr/devicetree.h>
@@ -29,8 +29,13 @@
 #endif
 #endif
 
+#ifdef CONFIG_MCUBOOT_BOOTLOADER_MODE_RAM_LOAD
+/* For RAM LOAD mode, the active image must be fetched from the bootloader */
+#define UPLOAD_FLASH_AREA_ID flash_img_get_upload_slot()
+#else
 /* FIXED_PARTITION_ID() values used below are auto-generated by DT */
 #define UPLOAD_FLASH_AREA_ID FIXED_PARTITION_ID(UPLOAD_FLASH_AREA_LABEL)
+#endif /* CONFIG_MCUBOOT_BOOTLOADER_MODE_RAM_LOAD */
 #define UPLOAD_FLASH_AREA_CONTROLLER \
 	DT_GPARENT(DT_NODELABEL(UPLOAD_FLASH_AREA_LABEL))
 
@@ -145,6 +150,25 @@ int flash_img_init_id(struct flash_img_context *ctx, uint8_t area_id)
 			ctx->flash_area->fa_size, NULL);
 }
 
+#ifdef CONFIG_MCUBOOT_BOOTLOADER_MODE_RAM_LOAD
+uint8_t flash_img_get_upload_slot(void)
+{
+	uint8_t slot;
+
+	slot = boot_fetch_active_slot();
+
+	if (slot == FIXED_PARTITION_ID(slot0_partition)) {
+		return FIXED_PARTITION_ID(slot1_partition);
+	}
+	return FIXED_PARTITION_ID(slot0_partition);
+}
+#else  /* CONFIG_MCUBOOT_BOOTLOADER_MODE_RAM_LOAD */
+uint8_t flash_img_get_upload_slot(void)
+{
+	return UPLOAD_FLASH_AREA_ID;
+}
+#endif /* CONFIG_MCUBOOT_BOOTLOADER_MODE_RAM_LOAD */
+
 int flash_img_init(struct flash_img_context *ctx)
 {
 	return flash_img_init_id(ctx, UPLOAD_FLASH_AREA_ID);