Squashed commit of the following:

board/boarctl.c:  Add support for the new BOARDIOC_ROMDISK command.  This allows applications to create ROMFS block drivers without illegal direct calls to romdisk_register.

    include/sys/boardctl.h:  Add basic definitions to support a ROM disk creation boardctl() command.

TODO

@@ -17,7 +17,7 @@ nuttx/:
   (2)  pthreads (sched/pthread, libs/libc/pthread)
   (0)  Message Queues (sched/mqueue)
   (1)  Work Queues (sched/wqueue)
-  (9)  Kernel/Protected Build
+  (8)  Kernel/Protected Build
   (3)  C++ Support
   (5)  Binary loaders (binfmt/)
  (17)  Network (net/, drivers/net)
@@ -926,27 +926,6 @@ o Work Queues (sched/wqueue)
 o Kernel/Protected Build
   ^^^^^^^^^^^^^^^^^^^^^^
 
-  Title:       NSH PARTITIONING.
-  Description: There are issues with NSH in the NuttX kernel and protected
-               build modes (where NuttX is built as a monolithic kernel and
-               user code must trap into the protected kernel via syscalls).
-               This can cause link failures in the kernel/protected build
-               mode and must currently be disabled.
-
-               Many such issues have been fixed.  Here are the known
-               remaingin problems that must be fixed:
-
-               - apps/nshlib/nsh_romfsetc.c:  The function nsh_romfsetc()
-                 calles romdisk_register() directly in order to register
-                 the application ROMFS file system.  This logic needs to
-                 be redesigned.  The best solution would simply to be to
-                 to create the romdisk in the board start-up logic.  This
-                 would, however, have impacts to NuttX users.
-
-  Status:      Open
-  Priority:    Medium/High -- the kernel build configuration is not fully fielded
-               yet.
-
   Title:       apps/system PARTITIONING
   Description: Several of the USB device helper applications in apps/system
                violate OS/application partitioning and will fail on a kernel
@@ -2859,10 +2838,10 @@ o Other Applications & Tests (apps/examples/)
                These examples are simple demos and, hence, you could argue that
                it is not so bad that they violate the interface for the purpose
                of demonstration (although they do set a bad example because of
-               this).  But there is other non-compliant logic:
+               this).
 
-                 graphics/traveler/trv_romfs.c, nshlib/nsh_romfsetc.c
+               These examples should, of course, use boardctl(BOARDIOC_ROMDISK)
-
+               to create the ROM disk instead of calling romdisk_register()
-               The NSH issue is listed under"Kernel/Protected Build" as well.
+               directly.
   Status:      Open
   Priority:    Medium.

boards/Kconfig

@@ -2836,6 +2836,21 @@ config BOARDCTL_UNIQUEID_SIZE
 		Provides the size of the memory buffer that must be provided by the
 		caller of board_uniqueid() in which to receive the board unique ID.
 
+config BOARDCTL_MKRD
+	bool "Enable application space creation of RAM disks"
+	default n
+	select DRVR_MKRD
+	depends on !DISABLE_MOUNTPOINT
+	---help---
+		Enables support for the BOARDIOC_MKRD boardctl() command.
+
+config BOARDCTL_ROMDISK
+	bool "Enable application space creation of ROM disks"
+	default n
+	depends on !DISABLE_MOUNTPOINT
+	---help---
+		Enables support for the BOARDIOC_MKRD boardctl() command.
+
 config BOARDCTL_APP_SYMTAB
 	bool "Enable application symbol table interfaces"
 	default n

boards/boardctl.c

@@ -358,11 +358,11 @@ int boardctl(unsigned int cmd, uintptr_t arg)
         break;
 #endif
 
-#ifdef CONFIG_DRVR_MKRD
+#ifdef CONFIG_BOARDCTL_MKRD
       /* CMD:           BOARDIOC_MKRD
        * DESCRIPTION:   Create a RAM disk
        * ARG:           Pointer to read-only instance of struct boardioc_mkrd_s.
-       * CONFIGURATION: CONFIG_DRVR_MKRD
+       * CONFIGURATION: CONFIG_BOARDCTL_MKRD
        * DEPENDENCIES:  None
        */
 
@@ -384,6 +384,32 @@ int boardctl(unsigned int cmd, uintptr_t arg)
         break;
 #endif
 
+#ifdef CONFIG_BOARDCTL_ROMDISK
+      /* CMD:           BOARDIOC_ROMDISK
+       * DESCRIPTION:   Reigster
+       * ARG:           Pointer to read-only instance of struct boardioc_romdisk_s.
+       * CONFIGURATION: CONFIG_BOARDCTL_ROMDISK
+       * DEPENDENCIES:  None
+       */
+
+      case BOARDIOC_ROMDISK:
+        {
+          FAR const struct boardioc_romdisk_s *desc =
+            (FAR const struct boardioc_romdisk_s *)arg;
+
+          if (desc == NULL)
+            {
+              ret = -EINVAL;
+            }
+          else
+            {
+              ret = romdisk_register((int)desc->minor, desc->image, desc->nsectors,
+                                     desc->sectsize);
+            }
+        }
+        break;
+#endif
+
 #ifdef CONFIG_BOARDCTL_APP_SYMTAB
       /* CMD:           BOARDIOC_APP_SYMTAB
        * DESCRIPTION:   Select the application symbol table.  This symbol table

include/sys/boardctl.h

@@ -99,7 +99,13 @@
  * CMD:           BOARDIOC_MKRD
  * DESCRIPTION:   Create a RAM disk
  * ARG:           Pointer to read-only instance of struct boardioc_mkrd_s.
- * CONFIGURATION: CONFIG_DRVR_MKRD
+ * CONFIGURATION: CONFIG_BOARDCTL_MKRD
+ * DEPENDENCIES:  None
+ *
+ * CMD:           BOARDIOC_ROMDISK
+ * DESCRIPTION:   Reigster
+ * ARG:           Pointer to read-only instance of struct boardioc_romdisk_s.
+ * CONFIGURATION: CONFIG_BOARDCTL_ROMDISK
  * DEPENDENCIES:  None
  *
  * CMD:           BOARDIOC_APP_SYMTAB
@@ -188,15 +194,16 @@
 #define BOARDIOC_RESET             _BOARDIOC(0x0004)
 #define BOARDIOC_UNIQUEID          _BOARDIOC(0x0005)
 #define BOARDIOC_MKRD              _BOARDIOC(0x0006)
-#define BOARDIOC_APP_SYMTAB        _BOARDIOC(0x0007)
+#define BOARDIOC_ROMDISK           _BOARDIOC(0x0007)
-#define BOARDIOC_OS_SYMTAB         _BOARDIOC(0x0008)
+#define BOARDIOC_APP_SYMTAB        _BOARDIOC(0x0008)
-#define BOARDIOC_BUILTINS          _BOARDIOC(0x0009)
+#define BOARDIOC_OS_SYMTAB         _BOARDIOC(0x0009)
-#define BOARDIOC_USBDEV_CONTROL    _BOARDIOC(0x000a)
+#define BOARDIOC_BUILTINS          _BOARDIOC(0x000a)
-#define BOARDIOC_NX_START          _BOARDIOC(0x000b)
+#define BOARDIOC_USBDEV_CONTROL    _BOARDIOC(0x000b)
-#define BOARDIOC_VNC_START         _BOARDIOC(0x000c)
+#define BOARDIOC_NX_START          _BOARDIOC(0x000c)
-#define BOARDIOC_NXTERM            _BOARDIOC(0x000d)
+#define BOARDIOC_VNC_START         _BOARDIOC(0x000d)
-#define BOARDIOC_NXTERM_IOCTL      _BOARDIOC(0x000e)
+#define BOARDIOC_NXTERM            _BOARDIOC(0x000e)
-#define BOARDIOC_TESTSET           _BOARDIOC(0x000f)
+#define BOARDIOC_NXTERM_IOCTL      _BOARDIOC(0x000f)
+#define BOARDIOC_TESTSET           _BOARDIOC(0x0010)
 
 /* If CONFIG_BOARDCTL_IOCTL=y, then board-specific commands will be support.
  * In this case, all commands not recognized by boardctl() will be forwarded
@@ -205,7 +212,7 @@
  * User defined board commands may begin with this value:
  */
 
-#define BOARDIOC_USER              _BOARDIOC(0x0010)
+#define BOARDIOC_USER              _BOARDIOC(0x0011)
 
 /****************************************************************************
  * Public Type Definitions
@@ -213,7 +220,7 @@
 
 /* Structures used with IOCTL commands */
 
-#ifdef CONFIG_DRVR_MKRD
+#ifdef CONFIG_BOARDCTL_MKRD
 /* Describes the RAM disk to be created */
 
 struct boardioc_mkrd_s
@@ -225,6 +232,18 @@ struct boardioc_mkrd_s
 };
 #endif
 
+#ifdef CONFIG_BOARDCTL_ROMDISK
+/* Describes the ROM disk image to be registered */
+
+struct boardioc_romdisk_s
+{
+  uint8_t minor;      /* Minor device number of the RAM disk. */
+  uint32_t nsectors;  /* The number of sectors in the RAM disk */
+  uint16_t sectsize;  /* The size of one sector in bytes */
+  FAR const uint8_t *image;
+};
+#endif
+
 /* In order to full describe a symbol table, a vector containing the address
  * of the symbol table and the number of elements in the symbol table is
  * required.