Add flexible file system and POSIX file API support

.gitmodules

@@ -13,3 +13,9 @@
 [submodule "lib/btstack"]
 	path = lib/btstack
 	url = https://github.com/bluekitchen/btstack.git
+[submodule "lib/pico-vfs"]
+	path = lib/pico-vfs
+	url = https://github.com/oyama/pico-vfs.git
+[submodule "lib/littlefs"]
+	path = lib/littlefs
+	url = https://github.com/littlefs-project/littlefs.git

src/cmake/rp2_common.cmake

@@ -120,6 +120,8 @@ if (NOT PICO_BARE_METAL)
     pico_add_subdirectory(rp2_common/pico_stdio_usb)
     pico_add_subdirectory(rp2_common/pico_i2c_slave)
 
+    pico_add_subdirectory(rp2_common/pico_filesystem)
+
     # networking libraries - note dependency order is important
     pico_add_subdirectory(rp2_common/pico_async_context)
     pico_add_subdirectory(rp2_common/pico_btstack)

src/rp2_common/pico_filesystem/CMakeLists.txt

@@ -0,0 +1,138 @@
+if (NOT PICO_VFS_PATH)
+    set(PICO_VFS_PATH ${PROJECT_SOURCE_DIR}/lib/pico-vfs)
+    if (NOT EXISTS ${PICO_VFS_PATH}/tests)
+        message(WARNING "pico-vfs submodule has not been initialized: File system support will be unavailable
+hint: try 'git submodule update --init' from your SDK directory (${PICO_SDK_PATH}).")
+    endif()
+    if (NOT EXISTS ${PROJECT_SOURCE_DIR}/lib/littlefs/tests)
+        message(WARNING "littlefs submodule has not been initialized: File system support will be unavailabel
+hint: try 'git submodule update --init' from your SDK directory (${PICO_SDK_PATH}).")
+    endif()
+elseif (NOT EXISTS ${PICO_VFS_PATH}/tests)
+    message(WARNING "PICO_VFS_PATH specified but content not present.")
+endif()
+
+if (EXISTS ${PICO_VFS_PATH}/tests)
+    message("pico-vfs available at ${PICO_VFS_PATH}/tests; enabling build support for file system.")
+
+    pico_register_common_scope_var(PICO_VFS_PATH)
+
+    pico_add_library(pico_filesystem_blockdevice_sd)
+    target_sources(pico_filesystem_blockdevice_sd INTERFACE
+        ${PICO_VFS_PATH}/src/blockdevice/sd.c)
+    target_include_directories(pico_filesystem_blockdevice_sd INTERFACE
+        ${PICO_VFS_PATH}/include)
+    target_link_libraries(pico_filesystem_blockdevice_sd INTERFACE
+        hardware_spi
+        pico_sync
+        )
+
+    pico_add_library(pico_filesystem_blockdevice_flash)
+    target_sources(pico_filesystem_blockdevice_flash INTERFACE
+        ${PICO_VFS_PATH}/src/blockdevice/flash.c)
+    target_include_directories(pico_filesystem_blockdevice_flash INTERFACE
+        ${PICO_VFS_PATH}/include)
+    target_link_libraries(pico_filesystem_blockdevice_flash INTERFACE
+        hardware_exception
+        hardware_flash
+        pico_sync
+        pico_flash
+        )
+
+    pico_add_library(pico_filesystem_blockdevice_heap)
+    target_sources(pico_filesystem_blockdevice_heap INTERFACE
+        ${PICO_VFS_PATH}/src/blockdevice/heap.c)
+    target_include_directories(pico_filesystem_blockdevice_heap INTERFACE
+        ${PICO_VFS_PATH}/include)
+    target_link_libraries(pico_filesystem_blockdevice_heap INTERFACE pico_sync)
+
+    pico_add_library(pico_filesystem_filesystem_littlefs)
+    target_sources(pico_filesystem_filesystem_littlefs INTERFACE
+        ${PICO_VFS_PATH}/src/filesystem/littlefs.c
+        ${PROJECT_SOURCE_DIR}/lib/littlefs/lfs.c
+        ${PROJECT_SOURCE_DIR}/lib/littlefs/lfs_util.c
+        )
+    target_include_directories(pico_filesystem_filesystem_littlefs INTERFACE
+        ${PROJECT_SOURCE_DIR}/lib/littlefs)
+    target_compile_options(pico_filesystem_filesystem_littlefs INTERFACE -Wno-unused-function -Wno-null-dereference)
+    target_link_libraries(pico_filesystem_filesystem_littlefs INTERFACE pico_sync)
+
+    pico_add_library(pico_filesystem_filesystem_fat)
+    target_sources(pico_filesystem_filesystem_fat INTERFACE
+        ${PICO_VFS_PATH}/src/filesystem/fat.c
+        ${PICO_VFS_PATH}/vendor/ff15/source/ff.c
+        ${PICO_VFS_PATH}/vendor/ff15/source/ffsystem.c
+        ${PICO_VFS_PATH}/vendor/ff15/source/ffunicode.c
+        )
+    target_include_directories(pico_filesystem_filesystem_fat INTERFACE
+        ${PICO_VFS_PATH}
+        ${PICO_VFS_PATH}/include/filesystem/ChaN
+        ${PICO_VFS_PATH}/vendor/ff15/source
+        )
+    target_link_libraries(pico_filesystem_filesystem_fat INTERFACE pico_sync)
+
+    pico_add_library(pico_filesystem)
+    target_sources(pico_filesystem INTERFACE
+        ${PICO_VFS_PATH}/src/filesystem/vfs.c)
+    target_include_directories(pico_filesystem INTERFACE
+        ${CMAKE_CURRENT_LIST_DIR}/include
+        ${PICO_VFS_PATH}/include)
+    target_link_libraries(pico_filesystem INTERFACE
+        pico_clib_interface
+        pico_sync
+        )
+
+    pico_add_library(pico_filesystem_default)
+    target_sources(pico_filesystem_default INTERFACE
+        ${PICO_VFS_PATH}/src/filesystem/fs_init.c)
+    target_include_directories(pico_filesystem_default INTERFACE
+        ${PICO_VFS_PATH}/include)
+    target_link_libraries(pico_filesystem_default INTERFACE
+        pico_filesystem
+        pico_filesystem_blockdevice_flash
+        pico_filesystem_filesystem_littlefs
+        )
+
+    pico_promote_common_scope_vars()
+
+    #
+    # File system enable and customise function
+    #
+    function(pico_enable_filesystem TARGET)
+        set(options "")
+        set(oneValueArgs SIZE AUTO_INIT MAX_FAT_VOLUME MAX_MOUNTPOINT)
+        set(multiValueArgs FS_INIT)
+        cmake_parse_arguments(ARG "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
+
+        # Default file system size in bytes. Must be a multiple of 4096 bytes
+        if(ARG_SIZE)
+            target_compile_definitions(${TARGET} PRIVATE PICO_FS_DEFAULT_SIZE=${ARG_SIZE})
+        endif()
+
+        # Add custom fs_init.c source files
+        if(ARG_FS_INIT)
+            target_sources(${TARGET} PRIVATE ${ARG_FS_INIT})
+        else()
+            target_link_libraries(${TARGET} PRIVATE pico_filesystem_default)
+        endif()
+
+        # Enable automatic execution of fs_init()
+        if(ARG_AUTO_INIT)
+            target_compile_definitions(${TARGET} PRIVATE PICO_FS_AUTO_INIT=1)
+        endif()
+
+        # Maximum number of file system mount points
+        if(ARG_MAX_MOUNTPOINT)
+            target_compile_definitions(${TARGET} PRIVATE PICO_VFS_MAX_MOUNTPOINT=${ARG_MAX_MOUNTPOINT})
+        else()
+            target_compile_definitions(${TARGET} PRIVATE PICO_VFS_MAX_MOUNTPOINT=8)
+        endif()
+
+        # Maximum number of volumes in a FAT file system
+        if(ARG_MAX_FAT_VOLUME)
+            target_compile_definitions(${TARGET} PRIVATE PICO_VFS_MAX_FAT_VOLUME=${ARG_MAX_FAT_VOLUME})
+        else()
+            target_compile_definitions(${TARGET} PRIVATE PICO_VFS_MAX_FAT_VOLUME=4)
+        endif()
+    endfunction()
+endif()

src/rp2_common/pico_filesystem/include/pico/filesystem.h

@@ -0,0 +1,10 @@
+/*
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#pragma once
+
+#include "filesystem/vfs.h"
+
+#if !defined(PICO_FS_DEFAULT_SIZE)
+#define PICO_FS_DEFAULT_SIZE       1441792
+#endif

src/rp2_common/pico_filesystem/include/pico/filesystem/blockdevice.h

@@ -0,0 +1,7 @@
+/*
+ * Copyright 2024, Hiroyuki OYAMA. All rights reserved.
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#pragma once
+
+#include "blockdevice/blockdevice.h"

src/rp2_common/pico_filesystem/include/pico/filesystem/blockdevice/flash.h

@@ -0,0 +1,6 @@
+/*
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#pragma once
+
+#include "blockdevice/flash.h"

src/rp2_common/pico_filesystem/include/pico/filesystem/blockdevice/heap.h

@@ -0,0 +1,6 @@
+/*
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#pragma once
+
+#include "blockdevice/heap.h"

src/rp2_common/pico_filesystem/include/pico/filesystem/blockdevice/sd.h

@@ -0,0 +1,6 @@
+/*
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#pragma once
+
+#include "blockdevice/sd.h"

src/rp2_common/pico_filesystem/include/pico/filesystem/filesystem.h

@@ -0,0 +1,7 @@
+/*
+ * Copyright 2024, Hiroyuki OYAMA. All rights reserved.
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#pragma once
+
+#include "filesystem/filesystem.h"

src/rp2_common/pico_filesystem/include/pico/filesystem/filesystem/fat.h

@@ -0,0 +1,6 @@
+/*
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#pragma once
+
+#include "filesystem/fat.h"

src/rp2_common/pico_filesystem/include/pico/filesystem/filesystem/littlefs.h

@@ -0,0 +1,6 @@
+/*
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#pragma once
+
+#include "filesystem/littlefs.h"