sched/init: Add option to mount block device for INIT_FILEPATH case

sched/Kconfig

@@ -363,6 +363,40 @@ config INIT_NEXPORTS
 		Any kernel mode symbols tables would not be usable for resolving
 		symbols in user mode executables.
 
+menuconfig INIT_MOUNT
+	bool "Auto-mount init file system"
+	default n
+	depends on !DISABLE_MOUNTPOINT
+	---help---
+		In order to use the the initial startup program when CONFIG_INIT_FILEPATH
+		is provided, it is necessary to mount the initial file system that
+		provides init program.  Normally this mount is done in the board-specific
+		initialization logic.  However, if the mount is very simple, it can be
+		performed by the OS bring-up logic itself by selecting this option.
+
+if INIT_MOUNT
+
+config INIT_MOUNT_SOURCE
+	string "The block device to mount"
+	default "/dev/ram0"
+
+config INIT_MOUNT_TARGET
+	string "Path to the mounted file system"
+	default "/bin"
+
+config INIT_MOUNT_FSTYPE
+	string "The file system type to mount"
+	default "romfs"
+
+config INIT_MOUNT_FLAGS
+	hex "Flags passed to mount"
+	default 0
+
+config INIT_MOUNT_DATA
+	string "Additional data passed to mount"
+	default ""
+
+endif # INIT_MOUNT
 endif # INIT_FILEPATH
 
 config RR_INTERVAL

sched/init/os_bringup.c

@@ -45,7 +45,9 @@
 
 #include <sched.h>
 #include <stdlib.h>
+#include <string.h>
 #include <debug.h>
+#include <sys/mount.h>
 
 #include <nuttx/arch.h>
 #include <nuttx/board.h>
@@ -98,10 +100,6 @@
    * program.
    */
 
-#    ifndef CONFIG_BOARD_INITIALIZE
-#      warning You probably need CONFIG_BOARD_INITIALIZE to mount the file system
-#    endif
-
 #    ifndef CONFIG_USER_INITPATH
   /* Path to the initialization program must have been provided */
 
@@ -287,6 +285,16 @@ static inline void os_do_appstart(void)
   board_initialize();
 #endif
 
+#ifdef CONFIG_INIT_MOUNT
+  /* Mount the file system containing the init program. */
+
+  ret = mount(CONFIG_INIT_MOUNT_SOURCE, CONFIG_INIT_MOUNT_TARGET,
+              CONFIG_INIT_MOUNT_FSTYPE, CONFIG_INIT_MOUNT_FLAGS,
+              CONFIG_INIT_MOUNT_DATA);
+  DEBUGASSERT(ret >= 0);
+  UNUSED(ret);
+#endif
+
   /* Start the application initialization program from a program in a
    * mounted file system.  Presumably the file system was mounted as part
    * of the board_initialize() operation.
@@ -297,6 +305,7 @@ static inline void os_do_appstart(void)
   ret = exec(CONFIG_USER_INITPATH, NULL, CONFIG_INIT_SYMTAB,
              CONFIG_INIT_NEXPORTS);
   ASSERT(ret >= 0);
+  UNUSED(ret);
 }
 
 #elif defined(CONFIG_INIT_NONE)