Add dmffs config directory mounting at /configs/

CMakeLists.txt

@@ -9,6 +9,7 @@ cmake_minimum_required(VERSION 3.10)
 set(TARGET "STM32F746xG" CACHE STRING "Target microcontroller")
 set(STARTUP_DMP_FILE "" CACHE FILEPATH "Optional startup.dmp file to embed in ROM")
 set(USER_DATA_FILE "" CACHE FILEPATH "Optional user_data file to embed in ROM")
+set(DMBOOT_CONFIG_DIR "" CACHE PATH "Optional config directory to mount as /configs/ using dmffs")
 option(DMBOOT_EMULATION "Enable Renode emulation mode" OFF)
 
 # ======================================================================
@@ -74,6 +75,17 @@ else()
     message(STATUS "No user data file provided (USER_DATA_FILE not set or file doesn't exist)")
 endif()
 
+# Include romfs.cmake to handle config filesystem embedding
+include(scripts/romfs.cmake)
+if(CONFIG_FS_OBJECT)
+    list(APPEND EMBEDDED_OBJECTS "${CONFIG_FS_OBJECT}")
+    # Add dependency on the filesystem generation
+    add_custom_command(
+        OUTPUT "${CONFIG_FS_OBJECT}"
+        DEPENDS generate_config_fs
+    )
+endif()
+
 # Embed modules.dmp if it exists after build
 # Note: modules.dmp is created during build, not configuration, so we check for it at build time
 set(MODULES_DMP_FILE "${CMAKE_BINARY_DIR}/modules.dmp")

README.md

@@ -37,13 +37,15 @@ cmake -DCMAKE_BUILD_TYPE=Debug \
       -DTARGET=STM32F746xG \
       -DSTARTUP_DMP_FILE=path/to/startup.dmp \
       -DUSER_DATA_FILE=path/to/user_data.dat \
+      -DDMBOOT_CONFIG_DIR=path/to/config_directory \
       -S . -B build
 cmake --build build
 ```
 
 **Build Parameters:**
 - `STARTUP_DMP_FILE` (optional) - Path to a startup package file (`.dmp`) that will be automatically loaded using `Dmod_AddPackageBuffer` at boot
 - `USER_DATA_FILE` (optional) - Path to a user data file that will be embedded in ROM, with its address and size available via environment variables `USER_DATA_ADDR` and `USER_DATA_SIZE`
+- `DMBOOT_CONFIG_DIR` (optional) - Path to a directory that will be converted to a dmffs filesystem image and mounted at `/configs/` at boot time
 - `DMBOOT_EMULATION` (optional) - Enable Renode simulation mode instead of hardware mode
 
 **Automatic Build-Time Embedding:**

linker/common.ld

@@ -113,6 +113,18 @@ SECTIONS
        PROVIDE(__modules_dmp_size = __modules_dmp_end - __modules_dmp_start);
    } > rom AT > rom
 
+   . = ALIGN(16);
+   .embedded.config_fs :
+   {
+       __config_fs_start = .;
+       PROVIDE(__config_fs_start = .);
+       KEEP(*(.embedded.config_fs))
+       __config_fs_end = .;
+       PROVIDE(__config_fs_end = .);
+       __config_fs_size = __config_fs_end - __config_fs_start;
+       PROVIDE(__config_fs_size = __config_fs_end - __config_fs_start);
+   } > rom AT > rom
+
    . = ALIGN(4);
    __exidx_start__ = .;
    PROVIDE(__exidx_start__ = __exidx_start__);

scripts/romfs.cmake

@@ -1,9 +1,71 @@
 # This script sets up a ROM filesystem using dmffs and integrates it into the build
 # It checks for the required tools, creates the ROMFS image, and embeds it into the firmware
 
-# Check if DMBOOT_ROMFS_DIR is set and exists
-if(DMBOOT_ROMFS_DIR AND EXISTS "${DMBOOT_ROMFS_DIR}")
-    message(STATUS "ROMFS directory specified: ${DMBOOT_ROMFS_DIR}")    
-    # Locate make_dmffs executable if not provided
-    if(NOT DMBOOT_MAKE_DMFFS_MODULE)
-        # Search the make_dmffs.dmf 
+# Check if DMBOOT_CONFIG_DIR is set and exists
+if(DMBOOT_CONFIG_DIR AND EXISTS "${DMBOOT_CONFIG_DIR}")
+    message(STATUS "Config directory specified: ${DMBOOT_CONFIG_DIR}")
+
+    # Set output path for the config filesystem image
+    set(CONFIG_FS_IMAGE "${CMAKE_BINARY_DIR}/config_fs.dmffs")
+
+    # Find make_dmffs tool
+    # First check if DMOD_DMF_DIR environment variable is set
+    if(DEFINED ENV{DMOD_DMF_DIR})
+        set(MAKE_DMFFS_MODULE "$ENV{DMOD_DMF_DIR}/make_dmffs.dmf")
+        if(EXISTS "${MAKE_DMFFS_MODULE}")
+            message(STATUS "Found make_dmffs.dmf at: ${MAKE_DMFFS_MODULE}")
+        else()
+            message(WARNING "DMOD_DMF_DIR is set but make_dmffs.dmf not found at: ${MAKE_DMFFS_MODULE}")
+            set(MAKE_DMFFS_MODULE "")
+        endif()
+    endif()
+
+    # If not found, try to use make_dmffs directly from PATH
+    if(NOT MAKE_DMFFS_MODULE)
+        find_program(DMOD_LOADER dmod_loader)
+        if(DMOD_LOADER)
+            message(STATUS "Found dmod_loader, will attempt to use make_dmffs module")
+            set(MAKE_DMFFS_COMMAND "${DMOD_LOADER}" "make_dmffs.dmf" "--args")
+        else()
+            message(FATAL_ERROR "Could not find make_dmffs tool. Please install it or set DMOD_DMF_DIR environment variable")
+        endif()
+    else()
+        find_program(DMOD_LOADER dmod_loader)
+        if(DMOD_LOADER)
+            set(MAKE_DMFFS_COMMAND "${DMOD_LOADER}" "${MAKE_DMFFS_MODULE}" "--args")
+        else()
+            message(FATAL_ERROR "Could not find dmod_loader executable")
+        endif()
+    endif()
+
+    # Create custom command to generate the config filesystem image
+    add_custom_command(
+        OUTPUT "${CONFIG_FS_IMAGE}"
+        COMMAND ${MAKE_DMFFS_COMMAND} -d "${DMBOOT_CONFIG_DIR}" -o "${CONFIG_FS_IMAGE}"
+        DEPENDS "${DMBOOT_CONFIG_DIR}"
+        COMMENT "Creating config filesystem image from ${DMBOOT_CONFIG_DIR}"
+        VERBATIM
+    )
+
+    # Create a custom target to ensure the filesystem image is generated
+    add_custom_target(generate_config_fs
+        DEPENDS "${CONFIG_FS_IMAGE}"
+    )
+
+    # Embed the config filesystem image
+    embed_binary_file(
+        INPUT_FILE "${CONFIG_FS_IMAGE}"
+        SECTION_NAME ".embedded.config_fs"
+        SYMBOL_PREFIX "__config_fs"
+    )
+
+    set(CONFIG_FS_OBJECT "${CMAKE_BINARY_DIR}/__config_fs.o")
+
+    # Export variables to parent scope
+    set(CONFIG_FS_OBJECT "${CONFIG_FS_OBJECT}" PARENT_SCOPE)
+    set(CONFIG_FS_IMAGE "${CONFIG_FS_IMAGE}" PARENT_SCOPE)
+
+    message(STATUS "Config filesystem will be embedded from: ${DMBOOT_CONFIG_DIR}")
+else()
+    message(STATUS "No config directory specified (DMBOOT_CONFIG_DIR not set or doesn't exist)")
+endif() 

src/main.c

@@ -22,6 +22,9 @@ extern void* __user_data_size;
 extern void* __modules_dmp_start;
 extern void* __modules_dmp_end;
 extern void* __modules_dmp_size;
+extern void* __config_fs_start;
+extern void* __config_fs_end;
+extern void* __config_fs_size;
 
 void delay(int cycles)
 {
@@ -266,6 +269,35 @@ static void setup_embedded_user_data(dmenv_ctx_t dmenv_ctx)
 static void mount_embedded_filesystems(void)
 {
     dmvfs_mount_fs("dmramfs", "/", NULL);
+
+    // Mount config filesystem if embedded
+    void* config_fs_start = &__config_fs_start;
+    void* config_fs_end   = &__config_fs_end;
+    size_t config_fs_size = (size_t)((uintptr_t)config_fs_end - (uintptr_t)config_fs_start);
+
+    if(config_fs_size > 0)
+    {
+        DMOD_LOG_INFO("Config filesystem found in ROM: addr=0x%X, size=%u bytes\n", 
+                      (uintptr_t)config_fs_start, (unsigned int)config_fs_size);
+
+        // Mount the dmffs filesystem at /configs/
+        char mount_opts[128];
+        Dmod_SnPrintf(mount_opts, sizeof(mount_opts), "addr=0x%X,size=%u", 
+                 (uintptr_t)config_fs_start, (unsigned int)config_fs_size);
+
+        if(dmvfs_mount_fs("dmffs", "/configs", mount_opts) == 0)
+        {
+            DMOD_LOG_INFO("Config filesystem mounted at /configs/\n");
+        }
+        else
+        {
+            DMOD_LOG_ERROR("Failed to mount config filesystem at /configs/\n");
+        }
+    }
+    else
+    {
+        DMOD_LOG_INFO("No config filesystem embedded in ROM\n");
+    }
 }
 
 int main(int argc, char** argv)