diff --git a/boards/st/b_u585i_iot02a/b_u585i_iot02a-common.dtsi b/boards/st/b_u585i_iot02a/b_u585i_iot02a-common.dtsi
index db1efe1ad36e7..f3713d9c5c6e8 100644
--- a/boards/st/b_u585i_iot02a/b_u585i_iot02a-common.dtsi
+++ b/boards/st/b_u585i_iot02a/b_u585i_iot02a-common.dtsi
@@ -146,16 +146,6 @@ stm32_lp_tick_source: &lptim1 {
 		data-rate = <OSPI_DTR_TRANSFER>;
 		four-byte-opcodes;
 		status = "okay";
-
-		partitions {
-			compatible = "fixed-partitions";
-			#address-cells = <1>;
-			#size-cells = <1>;
-
-			partition@0 {
-				reg = <0x00000000 DT_SIZE_M(64)>;
-			};
-		};
 	};
 };
 
diff --git a/boards/st/b_u585i_iot02a/b_u585i_iot02a.dts b/boards/st/b_u585i_iot02a/b_u585i_iot02a.dts
index fc824417d2050..cef7e05831fda 100644
--- a/boards/st/b_u585i_iot02a/b_u585i_iot02a.dts
+++ b/boards/st/b_u585i_iot02a/b_u585i_iot02a.dts
@@ -76,6 +76,18 @@
 	};
 };
 
+&mx25lm51245 {
+	partitions {
+		compatible = "fixed-partitions";
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		partition@0 {
+			reg = <0x00000000 DT_SIZE_M(64)>;
+		};
+	};
+};
+
 &gpdma1 {
 	status = "okay";
 };
diff --git a/boards/st/b_u585i_iot02a/b_u585i_iot02a_stm32u585xx_ns.dts b/boards/st/b_u585i_iot02a/b_u585i_iot02a_stm32u585xx_ns.dts
index 04e24e714947e..997fcd2133e66 100644
--- a/boards/st/b_u585i_iot02a/b_u585i_iot02a_stm32u585xx_ns.dts
+++ b/boards/st/b_u585i_iot02a/b_u585i_iot02a_stm32u585xx_ns.dts
@@ -34,44 +34,59 @@
 
 		/*
 		 * Following flash partition is compatible with requirements
-		 * given in TFM configuration given for current board.
-		 * It might require adjustment depending on evolutions on TFM.
+		 * given in TF-M configuration given for current board.
+		 *
+		 * It might require adjustment depending on evolutions on TF-M.
 		 */
-
 		boot_partition: partition@0 {
 			label = "mcuboot";
-			reg = <0x00000000 DT_SIZE_K(224)>;
+			reg = <0x00000000 DT_SIZE_K(384)>;
 			read-only;
 		};
 
 		/* Secure image primary slot */
-		slot0_partition: partition@38000 {
+		slot0_partition: partition@60000 {
 			label = "image-0";
-			reg = <0x00038000 DT_SIZE_K(384)>;
+			reg = <0x00060000 DT_SIZE_K(512)>;
 		};
 
 		/* Non-secure image primary slot */
-		slot0_ns_partition: partition@98000 {
+		slot0_ns_partition: partition@e0000 {
 			label = "image-0-nonsecure";
-			reg = <0x00098000 DT_SIZE_K(512)>;
+			reg = <0x000e0000 DT_SIZE_K(1024)>;
+		};
+
+		/* Internal Non Volatile Storage */
+		storage_partition: partition@1e0000 {
+			label = "storage";
+			reg = <0x001e0000 DT_SIZE_K(128)>;
 		};
+	};
+};
+
+&mx25lm51245 {
+	partitions {
+		compatible = "fixed-partitions";
+		#address-cells = <1>;
+		#size-cells = <1>;
 
-		/* Secure image secondary slot */
-		slot1_partition: partition@118000 {
+		/*
+		 * The flash partition (0 and 1) are aligned
+		 * with the TF-M flash layout expectation.
+		 */
+		slot1_partition: partition@0 {
 			label = "image-1";
-			reg = <0x00118000 DT_SIZE_K(384)>;
+			reg = <0x00000000 DT_SIZE_K(512)>;
 		};
 
-		/* Non-secure image secondary slot */
-		slot1_ns_partition: partition@178000 {
+		slot1_ns_partition: partition@80000 {
 			label = "image-1-nonsecure";
-			reg = <0x00178000 DT_SIZE_K(512)>;
+			reg = <0x00080000 DT_SIZE_K(1024)>;
 		};
 
-		/* Applicative Non Volatile Storage */
-		storage_partition: partition@1f8000 {
-			label = "storage";
-			reg = <0x001f8000 DT_SIZE_K(16)>;
+		external_partition: partition@180000 {
+			label = "external";
+			reg = <0x00180000 (DT_SIZE_M(64) - DT_SIZE_K(1024) - DT_SIZE_K(512))>;
 		};
 	};
 };
diff --git a/doc/releases/migration-guide-4.3.rst b/doc/releases/migration-guide-4.3.rst
index 866b21451a46d..565c58f78ee77 100644
--- a/doc/releases/migration-guide-4.3.rst
+++ b/doc/releases/migration-guide-4.3.rst
@@ -29,6 +29,11 @@ Kernel
 Boards
 ******
 
+* b_u585i_iot02a/ns: The flash layout was changed to be in sync with the upstream TF-M 2.2.1 board
+  configurations. The new layout expands the flash partitions, moving the secondary ones to the
+  external NOR flash. This change currently prevents upgrade from older Zephyr release images to
+  Zephyr 4.3 release images. More details in the TF-M migration and release notes.
+
 * mimxrt11x0: renamed lpadc1 to lpadc2 and renamed lpadc0 to lpadc1.
 
 * NXP ``frdm_mcxa166`` is renamed to ``frdm_mcxa346``.
diff --git a/tests/drivers/flash/common/boards/b_u585i_iot02a_stm32u585xx_ns.overlay b/tests/drivers/flash/common/boards/b_u585i_iot02a_stm32u585xx_ns.overlay
deleted file mode 100644
index 3d595140e95e5..0000000000000
--- a/tests/drivers/flash/common/boards/b_u585i_iot02a_stm32u585xx_ns.overlay
+++ /dev/null
@@ -1,21 +0,0 @@
-/*
- * Copyright (c) 2022, STMicroelectronics
- *
- * SPDX-License-Identifier: Apache-2.0
- */
-/ {
-	chosen {
-		zephyr,code-partition = &slot0_ns_partition;
-	};
-};
-
-&flash0 {
-	partitions {
-		/delete-node/ slot0_partition;
-		/* Non-secure image primary slot */
-		slot0_ns_partition: partition@98000 {
-			label = "image-0-nonsecure";
-			reg = <0x00098000 DT_SIZE_K(512)>;
-		};
-	};
-};
diff --git a/west.yml b/west.yml
index 3135f28ccbbc9..2c31a07070f1d 100644
--- a/west.yml
+++ b/west.yml
@@ -364,7 +364,7 @@ manifest:
       groups:
         - tee
     - name: trusted-firmware-m
-      revision: cc800268f79779fa674b7085ecf507eb95b83ff9
+      revision: 3e12b0cc27d828d7ec04c4ac62ad45a9a905573e
       path: modules/tee/tf-m/trusted-firmware-m
       groups:
         - tee