Added CMake.

CMakeLists.txt

@@ -0,0 +1,21 @@
+cmake_minimum_required(VERSION 3.10)
+
+project(fatfs)
+
+if(NOT FATFS_CONFIG_DIRECTORY)
+    message(FATAL_ERROR "FATFS_CONFIG_DIRECTORY should be defined")
+elseif(NOT EXISTS ${FATFS_CONFIG_DIRECTORY}/ffconf.h)
+    message(FATAL_ERROR "ffconf.h should be included in the directory.")
+endif()
+
+set(FATFS_SRCS
+    "source/ff.c"
+    "source/ffunicode.c"
+)
+
+set(FATFS_INCS
+    "include"
+)
+
+add_library(${PROJECT_NAME} ${FATFS_SRCS})
+target_include_directories(${PROJECT_NAME} PUBLIC ${FATFS_INCS} ${FREERTOS_CONFIG_FILE_DIRECTORY})