defunct: playing around with bootloaders

- Corrected device tree overlays to prevent MCUboot and app overlap
- MCUboot now at 0x8000000 (32KB), app at 0x8008000 (96KB)
- Successfully boots MCUboot which chains to application
- Shell and reset command working properly
- Black Magic Probe flashing confirmed working for both domains

software/.vscode/settings.json

@@ -8,5 +8,10 @@
 
 		// File Associations
 		"files.associations": {
+			"array": "c",
+			"string_view": "c",
+			"initializer_list": "c",
+			"span": "c",
+			"format": "c"
 		}
 }

software/apps/firmware_node/boards/flash_partitions_128kb.dtsi

@@ -0,0 +1,29 @@
+/*
+ * Flash partition layout for STM32G431 (128KB total flash)
+ * MCUboot + single application slot configuration
+ */
+
+&flash0 {
+        partitions {
+                compatible = "fixed-partitions";
+                #address-cells = <1>;
+                #size-cells = <1>;
+
+                boot_partition: partition@0 {
+                        label = "mcuboot";
+                        reg = <0x00000000 0x0000A000>; /* 40 KB for MCUboot */
+                        read-only;
+                };
+
+                slot0_partition: partition@A000 {
+                        label = "image-0";
+                        reg = <0x0000A000 0x00016000>; /* 88 KB for application */
+                };
+        };
+};
+
+/ {
+	chosen {
+		zephyr,code-partition = &slot0_partition;
+	};
+};

software/apps/firmware_node/boards/weact_stm32g431_core.overlay

@@ -0,0 +1,7 @@
+/*
+ * Copyright (c) 2021 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "flash_partitions_128kb.dtsi"

software/apps/firmware_node/boards/weact_stm32g431_core_mcuboot.overlay

@@ -0,0 +1,18 @@
+&flash0 {
+	partitions {
+		compatible = "fixed-partitions";
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		boot_partition: partition@0 {
+			label = "mcuboot";
+			reg = <0x00000000 0x00008000>; /* 32 KB */
+			read-only;
+		};
+
+		slot0_partition: partition@8000 {
+			label = "image-0";
+			reg = <0x00008000 0x00018000>; /* 96 KB */
+		};
+	};
+};

software/apps/firmware_node/pm.yml

@@ -0,0 +1,25 @@
+# Partition manager configuration for firmware_node
+
+# Boot partition (MCUboot)
+mcuboot_primary:
+  address: 0x00000000
+  size: 0x8000
+  region: flash_primary
+
+# Application partition (primary slot)
+mcuboot_primary_app:
+  address: 0x00008000
+  size: 0x18000
+  region: flash_primary
+
+# Secondary slot for updates
+mcuboot_secondary:
+  address: 0x00020000
+  size: 0x18000
+  region: flash_primary
+
+# Settings partition
+settings_partition:
+  address: 0x00038000
+  size: 0x8000
+  region: flash_primary

software/apps/firmware_node/prj.conf

@@ -1,6 +1,7 @@
 # Enable Console and printk for logging
 CONFIG_CONSOLE=y
 CONFIG_LOG=y
+CONFIG_LOG_PROCESS_THREAD=y
 
 # Enable Shell
 CONFIG_SHELL=y
@@ -8,3 +9,13 @@ CONFIG_REBOOT=y
 
 # Enable the reset command
 CONFIG_KERNEL_SHELL=y
+
+# Enable settings for persistent storage
+CONFIG_SETTINGS=y
+CONFIG_SETTINGS_NVS=y
+CONFIG_NVS=y
+
+# Enable Flash and Flash Map for image trailer manipulation
+CONFIG_FLASH=y
+CONFIG_FLASH_MAP=y
+CONFIG_FLASH_PAGE_LAYOUT=y

software/apps/firmware_node/src/main.c

@@ -1,28 +1,167 @@
 #include <zephyr/kernel.h>
+#include <zephyr/logging/log.h>
 #include <zephyr/shell/shell.h>
 #include <zephyr/sys/reboot.h>
-#include <zephyr/logging/log.h>
+#include <zephyr/drivers/flash.h>
+#include <zephyr/storage/flash_map.h>
+#include <zephyr/devicetree.h>
 
-LOG_MODULE_REGISTER(firmware_node, LOG_LEVEL_DBG);
+LOG_MODULE_REGISTER(firmware_node, LOG_LEVEL_INF);
 
+// Image header magic number (from MCUboot)
+#define IMAGE_MAGIC 0x96f3b83d
+#define IMAGE_HEADER_SIZE 32
+
+// Function to invalidate current image and trigger serial recovery
+static int invalidate_current_image(void)
+{
+    const struct flash_area *fa;
+    int rc;
+
+    // Get the flash area for the current image slot (slot0_partition)
+    rc = flash_area_open(FIXED_PARTITION_ID(slot0_partition), &fa);
+    if (rc != 0) {
+        LOG_ERR("Failed to open flash area: %d", rc);
+        return rc;
+    }
+
+    // Ensure the flash area is valid
+    if (fa->fa_id != FIXED_PARTITION_ID(slot0_partition)) {
+        LOG_ERR("Invalid flash area ID: %d", fa->fa_id);
+        flash_area_close(fa);
+        return -EINVAL;
+    }
+
+    // Get the flash device associated with this area
+    // This is necessary to perform erase operations
+
+    const struct device *flash_dev = flash_area_get_device(fa);
+    if (flash_dev == NULL) {
+        LOG_ERR("Failed to get flash device for area");
+        flash_area_close(fa);
+        return -ENODEV;
+    }
+
+    struct flash_pages_info page_info;
+    off_t last_block_offset;
+
+    // Find the last block of the flash area
+    rc = flash_get_page_info_by_offs(flash_dev, fa->fa_off + fa->fa_size - 1, &page_info);
+    if (rc != 0) {
+        LOG_ERR("Failed to get page info: %d", rc);
+        flash_area_close(fa);
+        return rc;
+    }
+
+    // Calculate the last block offset
+    rc = flash_get_page_info_by_offs(flash_dev, fa->fa_off + fa->fa_size - 1, &page_info);
+    if (rc != 0) {
+        LOG_ERR("Failed to get page info: %d", rc);
+        flash_area_close(fa);
+        return rc;
+    }
+    last_block_offset = page_info.start_offset;
+
+   // Convert absolute flash offset to relative offset within the flash area
+   off_t relative_offset = last_block_offset - fa->fa_off;
+   
+   // Erase the image trailer/metadata at the end of the partition
+   LOG_INF("Erasing image trailer at absolute offset: %ld, relative offset: %ld, size: %d bytes", 
+           last_block_offset, relative_offset, page_info.size);
+   rc = flash_area_erase(fa, relative_offset, page_info.size);
+   if (rc != 0) {
+       LOG_ERR("Failed to erase image trailer: %d", rc);
+  
+   } else {
+       LOG_INF("Image trailer erased successfully");
+   }
+   
+   flash_area_close(fa);
+   return rc;
+}
+// Custom reset command handler
 static int cmd_reset(const struct shell *shell, size_t argc, char **argv)
 {
     ARG_UNUSED(argc);
     ARG_UNUSED(argv);
     
-    shell_print(shell, "Rebooting system...");
-    k_msleep(100); // Give time for message to be sent
-    sys_reboot(SYS_REBOOT_WARM);
+    shell_print(shell, "Resetting system...");
+    k_msleep(100); // Give time for the message to be sent
+    sys_reboot(SYS_REBOOT_COLD);
     
     return 0;
 }
 
+// MCUboot serial recovery command handler
+static int cmd_recovery(const struct shell *shell, size_t argc, char **argv)
+{
+    ARG_UNUSED(argc);
+    ARG_UNUSED(argv);
+    
+    shell_print(shell, "Entering MCUboot serial recovery mode...");
+    shell_print(shell, "Corrupting current image magic to trigger recovery...");
+    
+    // Invalidate the current image by corrupting its header
+    int rc = invalidate_current_image();
+    if (rc != 0) {
+        shell_error(shell, "Failed to invalidate image: %d", rc);
+        return rc;
+    }
+    
+    shell_print(shell, "Image magic corrupted. System will reset and MCUboot will detect bad image.");
+    shell_print(shell, "MCUboot should show error and wait for recovery.");
+    k_msleep(100); // Give time for the message to be sent
+    
+    // Reset the system - MCUboot will detect invalid image and enter serial recovery
+    // log_process(true);
+    // sys_reboot(SYS_REBOOT_COLD);
+    
+    return 0;
+}
+
+// Command to show firmware info
+static int cmd_info(const struct shell *shell, size_t argc, char **argv)
+{
+    ARG_UNUSED(argc);
+    ARG_UNUSED(argv);
+    
+    const struct flash_area *fa;
+    int rc = flash_area_open(FIXED_PARTITION_ID(slot0_partition), &fa);
+    
+    if (rc != 0) {
+        shell_error(shell, "Failed to open flash area: %d", rc);
+        return rc;
+    }
+    
+    // Read the first few bytes to check the image header
+    uint32_t magic;
+    rc = flash_area_read(fa, 0, &magic, sizeof(magic));
+    if (rc == 0) {
+        shell_print(shell, "Image magic: 0x%08x", magic);
+        if (magic == IMAGE_MAGIC) {
+            shell_print(shell, "Image header is valid");
+            shell_print(shell, "Image starts at flash offset: 0x%lx", (unsigned long)fa->fa_off);
+            shell_print(shell, "Image partition size: %d bytes", fa->fa_size);
+        } else {
+            shell_print(shell, "Image header is INVALID (expected 0x%08x)", IMAGE_MAGIC);
+        }
+    } else {
+        shell_error(shell, "Failed to read image header: %d", rc);
+    }
+    
+    flash_area_close(fa);
+    return 0;
+}
+
 SHELL_CMD_REGISTER(reset, NULL, "Reset the system", cmd_reset);
+SHELL_CMD_REGISTER(recovery, NULL, "Enter MCUboot serial recovery mode", cmd_recovery);
+SHELL_CMD_REGISTER(info, NULL, "Show firmware info", cmd_info);
 
 int main(void)
 {
     LOG_INF("Firmware Node starting up");
     LOG_INF("Shell with reset command available");
+    LOG_INF("Serial recovery command available");
 
     return 0;
 }

software/apps/firmware_node/sysbuild.cmake

@@ -1,12 +1,4 @@
-# Enable MCUboot
-set(SB_CONFIG_BOOTLOADER_MCUBOOT y)
+# Sysbuild configuration for firmware_node with MCUboot
 
-# MCUboot configuration
-set(SB_CONFIG_MCUBOOT_BOOTLOADER_MODE_OVERWRITE_ONLY y)
-set(SB_CONFIG_MCUBOOT_SIGNATURE_KEY_FILE "bootloader/mcuboot/root-rsa-2048.pem")
-set(SB_CONFIG_MCUBOOT_GENERATE_UNSIGNED_IMAGE y)
-set(SB_CONFIG_MCUBOOT_GENERATE_CONFIRMED_IMAGE y)
-
-# Enable USB CDC ACM for MCUboot console
-set(SB_CONFIG_MCUBOOT_USB_SUPPORT y)
-set(SB_CONFIG_MCUBOOT_SERIAL y)
+# Enable MCUboot as bootloader
+set(SB_CONFIG_BOOTLOADER_MCUBOOT TRUE)

software/apps/firmware_node/sysbuild.conf

@@ -0,0 +1,5 @@
+# Sysbuild configuration for firmware_node with MCUboot
+
+# Enable MCUboot as bootloader
+SB_CONFIG_BOOTLOADER_MCUBOOT=y
+SB_CONFIG_MCUBOOT_MODE_SINGLE_APP=y

software/apps/firmware_node/sysbuild/firmware_node.overlay

@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) 2021 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "../boards/flash_partitions_128kb.dtsi"
+
+/ {
+	chosen {
+		zephyr,code-partition = &slot0_partition;
+	};
+};

software/apps/firmware_node/sysbuild/mcuboot.conf

@@ -0,0 +1,31 @@
+# MCUboot configuration for firmware_node
+# Enable basic console and logging for debugging
+CONFIG_LOG=y
+CONFIG_BOOT_BANNER=y
+CONFIG_CONSOLE=y
+CONFIG_UART_CONSOLE=y
+CONFIG_PRINTK=y
+
+# Single slot configuration (no upgrades)
+CONFIG_SINGLE_APPLICATION_SLOT=y
+
+# Enable serial recovery mode (temporarily commented out for debugging)
+# CONFIG_MCUBOOT_SERIAL=y
+# CONFIG_BOOT_SERIAL_UART=y
+# CONFIG_BOOT_SERIAL_DETECT_PORT=y
+
+# Disable signature validation for testing to save space
+CONFIG_BOOT_SIGNATURE_TYPE_NONE=y
+
+# Size optimizations to fit in 40KB flash
+CONFIG_SIZE_OPTIMIZATIONS=y
+CONFIG_CBPRINTF_NANO=y
+CONFIG_MINIMAL_LIBC=y
+CONFIG_ASSERT=n
+
+# Disable debug features for size
+CONFIG_DEBUG_INFO=n
+CONFIG_DEBUG_OPTIMIZATIONS=n
+
+# Minimal heap for size optimization
+CONFIG_HEAP_MEM_POOL_SIZE=0

software/apps/firmware_node/sysbuild/mcuboot.overlay

@@ -0,0 +1,12 @@
+/*
+ * MCUboot device tree overlay for firmware_node
+ * Uses shared flash partition layout
+ */
+
+#include "../boards/flash_partitions_128kb.dtsi"
+
+/ {
+	chosen {
+		zephyr,code-partition = &boot_partition;
+	};
+};

software/apps/firmware_node/sysbuild/mcuboot/boards/weact_stm32g431_core.overlay

@@ -0,0 +1,33 @@
+/*
+ * MCUboot specific overlay for weact_stm32g431_core
+ * This overlay defines flash partitions for MCUboot
+ */
+
+&flash0 {
+	partitions {
+		compatible = "fixed-partitions";
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		boot_partition: partition@0 {
+			label = "mcuboot";
+			reg = <0x00000000 0x00008000>;
+		};
+		slot0_partition: partition@8000 {
+			label = "image-0";
+			reg = <0x00008000 0x0000E000>;
+		};
+		slot1_partition: partition@16000 {
+			label = "image-1";
+			reg = <0x00016000 0x0000E000>;
+		};
+		storage_partition: partition@24000 {
+			label = "storage";
+			reg = <0x00024000 0x00004000>;
+		};
+	};
+};
+
+&chosen {
+	zephyr,boot-partition = &boot_partition;
+};

software/apps/snippets/bootloader/CMakeLists.txt

@@ -0,0 +1,8 @@
+cmake_minimum_required(VERSION 3.20)
+
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+
+project(bootloader LANGUAGES C)
+zephyr_include_directories(../../../include)
+add_subdirectory(../../../lib lib)
+target_sources(app PRIVATE src/main.c)

software/apps/snippets/bootloader/README.md

@@ -0,0 +1,34 @@
+# Firmware Node Application
+
+This Zephyr application provides firmware management capabilities for the irrigation system.
+
+**Tested on Zephyr 4.1.99**
+
+## Features
+
+### Step 1: Shell with Reset Command
+- Shell interface with custom "reset" command
+- Warm reboot functionality
+
+### Planned Features
+- MCUboot support with partition manager
+- Firmware version display
+- MCUmgr support for OTA updates
+
+## Building
+
+```bash
+west build -p auto -b weact_stm32g431_core apps/firmware_node -- -DBOARD_FLASH_RUNNER=blackmagicprobe
+```
+
+## Flashing
+
+```bash
+west flash
+```
+
+## Usage
+
+Connect to the device via serial console and use the shell:
+- `reset` - Reboot the system
+- `help` - Show available commands

software/apps/snippets/bootloader/VERSION

@@ -0,0 +1,5 @@
+VERSION_MAJOR = 0
+VERSION_MINOR = 0
+PATCHLEVEL = 1
+VERSION_TWEAK = 0
+EXTRAVERSION = testing

software/apps/snippets/bootloader/erase.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+/home/edi/zephyr-sdk-0.17.1/arm-zephyr-eabi/bin/arm-zephyr-eabi-gdb \
+	-ex 'target extended-remote /dev/ttyACM0' \
+	-ex 'monitor swdp_scan' \
+	-ex 'attach 1' \
+	-ex 'monitor erase_mass' \
+	-ex 'detach' \
+	-ex 'quit' \

software/apps/snippets/bootloader/prj.conf

@@ -0,0 +1,16 @@
+CONFIG_SHELL=y
+CONFIG_REBOOT=y
+
+# MCUboot support for recovery request function
+CONFIG_MCUBOOT_BOOTUTIL_LIB=y
+CONFIG_MCUBOOT_IMG_MANAGER=y
+CONFIG_IMG_MANAGER=y
+
+# Flash and Stream Configuration (required for IMG_MANAGER)
+CONFIG_FLASH=y
+CONFIG_STREAM_FLASH=y
+
+# Retention system
+CONFIG_RETENTION=y
+CONFIG_RETENTION_BOOT_MODE=y
+CONFIG_RETAINED_MEM=y

software/apps/snippets/bootloader/src/main.c

@@ -0,0 +1,42 @@
+#include <zephyr/kernel.h>
+#include <app_version.h>
+#include <zephyr/shell/shell.h>
+#include <zephyr/sys/reboot.h>
+#include <zephyr/dfu/mcuboot.h>
+#include <zephyr/retention/bootmode.h>
+#include <stdlib.h>
+
+/* Shell command handler for "reset" */
+static int cmd_reset(const struct shell *sh, size_t argc, char **argv)
+{
+    shell_print(sh, "Rebooting system...");
+    k_sleep(K_MSEC(100)); // Optional delay for user to see the message
+    sys_reboot(SYS_REBOOT_WARM);
+    return 0;
+}
+
+static int cmd_download(const struct shell *sh, size_t argc, char **argv)
+{
+    int rc;
+    
+    /* Set boot mode to serial recovery */
+    rc = bootmode_set(BOOT_MODE_TYPE_BOOTLOADER);
+    if (rc < 0) {
+        shell_error(sh, "Failed to set boot mode: %d", rc);
+        return rc;
+    }
+    
+    shell_print(sh, "Boot mode set to recovery. Rebooting to bootloader...");
+    k_sleep(K_MSEC(100));
+    sys_reboot(SYS_REBOOT_WARM);
+    return 0;
+}
+
+/* Register the shell command */
+SHELL_CMD_REGISTER(reset, NULL, "Reboot the system", cmd_reset);
+SHELL_CMD_REGISTER(download, NULL, "Download firmware", cmd_download);
+
+int main(void){
+    printk("Bootloader test version %s\n", APP_VERSION_EXTENDED_STRING);
+    return 0;
+}

software/apps/snippets/bootloader/sysbuild.conf

@@ -0,0 +1,5 @@
+# Sysbuild configuration for firmware_node with MCUboot
+
+# Enable MCUboot as bootloader
+SB_CONFIG_BOOTLOADER_MCUBOOT=y
+SB_CONFIG_MCUBOOT_MODE_SINGLE_APP=y

software/apps/snippets/bootloader/sysbuild/bootloader.overlay

@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) 2021 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "flash_partitions_128kb.dtsi"
+
+/ {
+	chosen {
+		zephyr,code-partition = &slot0_partition;
+	};
+};

software/apps/snippets/bootloader/sysbuild/flash_partitions_128kb.dtsi

@@ -0,0 +1,62 @@
+/*
+ * Devicetree Overlay for 128KB Flash
+ * - MCUboot Bootloader (32KB)
+ * - Application Slot (96KB)
+ */
+
+&flash0 {
+        /delete-node/ partitions;
+        partitions {
+                compatible = "fixed-partitions";
+                #address-cells = <1>;
+                #size-cells = <1>;
+
+                boot_partition: partition@0 {
+                        label = "mcuboot";
+                        reg = <0x00000000 DT_SIZE_K(32)>;
+                        read-only;
+                };
+
+                slot0_partition: partition@8000 {
+                        label = "image-0";
+                        reg = <0x00008000 DT_SIZE_K(96)>;
+                };
+        };
+};
+
+/* Add retention memory to the existing SRAM node */
+&sram0 {
+        #address-cells = <1>;
+        #size-cells = <1>;
+        
+        retainedmem {
+                compatible = "zephyr,retained-ram";
+                status = "okay";
+                #address-cells = <1>;
+                #size-cells = <1>;
+                
+                boot_mode: retention@7f00 {
+                        compatible = "zephyr,retention";
+                        status = "okay";
+                        reg = <0x7f00 0x100>;
+                        prefix = [08 04];
+                        checksum = <1>;
+                };
+        };
+};
+
+/ {
+        chosen {
+                zephyr,boot-mode = &boot_mode;
+                zephyr,console = &cdc_acm_uart0;
+    };
+};
+
+&zephyr_udc0 {
+    status = "okay";
+    
+    cdc_acm_uart0: cdc_acm_uart0 {
+        compatible = "zephyr,cdc-acm-uart";
+        label = "CDC_ACM_0";
+    };
+};

software/apps/snippets/bootloader/sysbuild/mcuboot.conf

@@ -0,0 +1,46 @@
+#
+# MCUboot Configuration for Serial Recovery over USB-CDC
+#
+
+# Enables serial recovery mode in MCUboot.
+CONFIG_MCUBOOT_SERIAL=y
+
+# Tell MCUboot to check for a trigger to enter recovery
+CONFIG_BOOT_SERIAL_BOOT_MODE=y
+
+# --- USB Stack Configuration ---
+CONFIG_USB_DEVICE_STACK=y
+CONFIG_USB_DEVICE_PRODUCT="MCUboot Serial Recovery"
+
+# Use USB CDC ACM for MCUboot serial recovery (not UART)
+CONFIG_BOOT_SERIAL_CDC_ACM=y
+
+# --- Disable Zephyr Console to avoid conflicts ---
+# MCUboot's serial_adapter doesn't work well with the general console subsystem.
+CONFIG_UART_CONSOLE=n
+CONFIG_CONSOLE_HANDLER=n
+CONFIG_CONSOLE=n
+
+# --- Flash and Stream Configuration (required for IMG_MANAGER) ---
+CONFIG_FLASH=y
+CONFIG_STREAM_FLASH=y
+
+# --- mcumgr Configuration ---
+# MCUMGR requires NET_BUF, even for serial transport.
+CONFIG_NET_BUF=y
+CONFIG_NET_LOG=n
+
+# Enables the mcumgr library and necessary command handlers
+CONFIG_MCUMGR=y
+CONFIG_IMG_MANAGER=y
+CONFIG_MCUMGR_GRP_IMG=y
+CONFIG_MCUMGR_GRP_OS=y
+
+# --- Retention Configuration ---
+CONFIG_RETAINED_MEM=y
+CONFIG_RETENTION=y
+CONFIG_RETENTION_BOOT_MODE=y
+
+# --- Optional: Reduce memory usage ---
+CONFIG_MAIN_STACK_SIZE=2048
+CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=1024

software/apps/snippets/bootloader/sysbuild/mcuboot.overlay

@@ -0,0 +1,17 @@
+#include "flash_partitions_128kb.dtsi"
+
+/ {
+    chosen {
+        zephyr,code-partition = &boot_partition;
+        zephyr,console = &cdc_acm_uart0;
+    };
+};
+
+&zephyr_udc0 {
+    status = "okay";
+    
+    cdc_acm_uart0: cdc_acm_uart0 {
+        compatible = "zephyr,cdc-acm-uart";
+        label = "CDC_ACM_0";
+    };
+};