Add NSH command to create RAMDISK

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@884 42af7a65-404d-4744-a932-0658087f49c3

14 files changed, 257 insertions, 55 deletions

diff --git a/nuttx/ChangeLog b/nuttx/ChangeLog
index a3ebf96e7..0fb5348d7 100644
--- a/nuttx/ChangeLog
+++ b/nuttx/ChangeLog
@@ -451,4 +451,6 @@
 	* NSH: Created an HTML document and a more detailed README file describing NSH.
 	* Added basic TFTP client logic (netutils/tftpc).  Untested as of initial check-in.
 	* NSH: Add get and put commands to support TFTP get and put operations.
+	* NSH: Added a mkrd command that will create a RAMDISK that can be formatted
+	  and mounted.
 
diff --git a/nuttx/Documentation/NuttShell.html b/nuttx/Documentation/NuttShell.html
index 2c8d8e2fb..fa8003a17 100644
--- a/nuttx/Documentation/NuttShell.html
+++ b/nuttx/Documentation/NuttShell.html
@@ -179,73 +179,79 @@
 <tr>
   <td><br></td>
   <td>
-    <a href="#cmdmount">2.18 Mount a File System (mount)</a>
+    <a href="#cmdmkrd">2.18 Create a RAMDISK (mkrd)</a>
   </td>
 </tr>
 <tr>
   <td><br></td>
   <td>
-    <a href="#cmdping">2.19 Check Network Peer (ping)</a>
+    <a href="#cmdmount">2.19 Mount a File System (mount)</a>
   </td>
 </tr>
 <tr>
   <td><br></td>
   <td>
-    <a href="#cmdput">2.20 Send File Via TFTP (put)</a>
+    <a href="#cmdping">2.20 Check Network Peer (ping)</a>
   </td>
 </tr>
 <tr>
   <td><br></td>
   <td>
-    <a href="#cmdpwd">2.21 Show Current Working Directory (pwd)</a>
+    <a href="#cmdput">2.21 Send File Via TFTP (put)</a>
   </td>
 </tr>
 <tr>
   <td><br></td>
   <td>
-    <a href="#cmdrm">2.22 Remove a File (rm)</a>
+    <a href="#cmdpwd">2.22 Show Current Working Directory (pwd)</a>
   </td>
 </tr>
 <tr>
   <td><br></td>
   <td>
-    <a href="#cmdrmdir">2.23 Remove a Directory (rmdir)</a>
+    <a href="#cmdrm">2.23 Remove a File (rm)</a>
   </td>
 </tr>
 <tr>
   <td><br></td>
   <td>
-    <a href="#cmdset">2.24 Set an Environment Variable (set)</a>
+    <a href="#cmdrmdir">2.24 Remove a Directory (rmdir)</a>
   </td>
 </tr>
 <tr>
   <td><br></td>
   <td>
-    <a href="#cmdsh">2.25 Execute an NSH Script (sh)</a>
+    <a href="#cmdset">2.25 Set an Environment Variable (set)</a>
   </td>
 </tr>
 <tr>
   <td><br></td>
   <td>
-    <a href="#cmdsleep">2.26 Wait for Seconds (sleep)</a>
+    <a href="#cmdsh">2.26 Execute an NSH Script (sh)</a>
   </td>
 </tr>
 <tr>
   <td><br></td>
   <td>
-    <a href="#cmdunmount">2.27 Unmount a File System (umount)</a>
+    <a href="#cmdsleep">2.27 Wait for Seconds (sleep)</a>
   </td>
 </tr>
 <tr>
   <td><br></td>
   <td>
-    <a href="#cmdunset">2.28 Unset an Environment Variable (unset)</a>
+    <a href="#cmdunmount">2.28 Unmount a File System (umount)</a>
   </td>
 </tr>
 <tr>
   <td><br></td>
   <td>
-    <a href="#cmdusleep">2.29 Wait for Microseconds (usleep)</a>
+    <a href="#cmdunset">2.29 Unset an Environment Variable (unset)</a>
+  </td>
+</tr>
+<tr>
+  <td><br></td>
+  <td>
+    <a href="#cmdusleep">2.30 Wait for Microseconds (usleep)</a>
   </td>
 </tr>
 <tr>
@@ -989,7 +995,58 @@ nsh>
 <table width ="100%">
   <tr bgcolor="#e4e4e4">
   <td>
-    <a name="cmdmount"><h2>2.18 Mount a File System (mount)</h2></a>
+    <a name="cmdmkrd"><h2>2.18 Create a RAMDISK (mkrd)</h2></a>
+  </td>
+</tr>
+</table>
+
+<p><b>Command Syntax:</b></p>
+<ul><pre>
+mkrd [-m &lt;minor&gt;] [-s &lt;sector-size&gt;] &lt;nsectors&gt;
+</pre></ul>
+<p>
+  <b>Synopsis</b>.
+  Create a ramdisk consisting of <code>&lt;nsectors&gt;</code>, each of size
+  <code>&lt;sector-size&gt;</code> (or 512 bytes if <code>&lt;sector-size&gt;</code> is not specified.
+  The ramdisk will be registered as <code>/dev/ram&lt;n&gt;</code> (if <code>&lt;n&gt;</code> is not
+  specified, mkrd will attempt to register the ramdisk as <code>/dev/ram0</code>.
+</p>
+<p><b>Example</b></p>
+<ul><pre>
+nsh&gt; ls /dev
+/dev:
+ console
+ null
+ ttyS0
+ ttyS1
+nsh&gt; mkrd 1024
+nsh&gt; ls /dev
+/dev:
+ console
+ null
+ ram0
+ ttyS0
+ ttyS1
+nsh&gt;
+</pre></ul>
+<p>
+  Once the ramdisk has been created, it may be formatted using
+  the <code>mkfatfs</code> command and mounted using the <code>mount</code> command.
+</p>
+<p><b>Example</b></p>
+<ul><pre>
+nsh&gt; mkrd 1024
+nsh&gt; mkfatfs /dev/ram0
+nsh&gt; mount -t vfat /dev/ram0 /tmp
+nsh&gt; ls /tmp
+/tmp:
+nsh&gt;
+</pre></ul>
+
+<table width ="100%">
+  <tr bgcolor="#e4e4e4">
+  <td>
+    <a name="cmdmount"><h2>2.19 Mount a File System (mount)</h2></a>
   </td>
 </tr>
 </table>
@@ -1056,7 +1113,7 @@ nsh>
 <table width ="100%">
   <tr bgcolor="#e4e4e4">
   <td>
-    <a name="cmdping"><h2>2.19 Check Network Peer (ping)</h2></a>
+    <a name="cmdping"><h2>2.20 Check Network Peer (ping)</h2></a>
   </td>
   </tr>
 </table>
@@ -1089,7 +1146,7 @@ nsh&gt;
 <table width ="100%">
   <tr bgcolor="#e4e4e4">
   <td>
-    <a name="cmdput"><h2>2.20 Send File Via TFTP (put)</h2></a>
+    <a name="cmdput"><h2>2.21 Send File Via TFTP (put)</h2></a>
   </td>
   </tr>
 </table>
@@ -1124,7 +1181,7 @@ put [-b|-n] [-f &lt;remote-path&gt;] -h &lt;ip-address&gt; &lt;local-path&gt;
 <table width ="100%">
   <tr bgcolor="#e4e4e4">
   <td>
-    <a name="cmdpwd"><h2>2.21 Show Current Working Directory (pwd)</h2></a>
+    <a name="cmdpwd"><h2>2.22 Show Current Working Directory (pwd)</h2></a>
   </td>
   </tr>
 </table>
@@ -1154,7 +1211,7 @@ nsh&gt;
 <table width ="100%">
   <tr bgcolor="#e4e4e4">
   <td>
-    <a name="cmdrm"><h2>2.22 Remove a File (rm)</h2></a>
+    <a name="cmdrm"><h2>2.23 Remove a File (rm)</h2></a>
   </td>
 </tr>
 </table>
@@ -1188,7 +1245,7 @@ nsh>
 <table width ="100%">
   <tr bgcolor="#e4e4e4">
   <td>
-    <a name="cmdrmdir"><h2>2.23 Remove a Directory (rmdir)</h2></a>
+    <a name="cmdrmdir"><h2>2.24 Remove a Directory (rmdir)</h2></a>
   </td>
 </tr>
 </table>
@@ -1223,7 +1280,7 @@ nsh>
 <table width ="100%">
   <tr bgcolor="#e4e4e4">
   <td>
-    <a name="cmdset"><h2>2.24 Set an Environment Variable (set)</h2></a>
+    <a name="cmdset"><h2>2.25 Set an Environment Variable (set)</h2></a>
   </td>
   </tr>
 </table>
@@ -1249,7 +1306,7 @@ nsh&gt;
 <table width ="100%">
   <tr bgcolor="#e4e4e4">
   <td>
-    <a name="cmdsh"><h2>2.25 Execute an NSH Script (sh)</h2></a>
+    <a name="cmdsh"><h2>2.26 Execute an NSH Script (sh)</h2></a>
   </td>
   </tr>
 </table>
@@ -1267,7 +1324,7 @@ sh &lt;script-path&gt;
 <table width ="100%">
   <tr bgcolor="#e4e4e4">
   <td>
-    <a name="cmdsleep"><h2>2.26 Wait for Seconds (sleep)</h2></a>
+    <a name="cmdsleep"><h2>2.27 Wait for Seconds (sleep)</h2></a>
   </td>
   </tr>
 </table>
@@ -1284,7 +1341,7 @@ sleep &lt;sec&gt;
 <table width ="100%">
   <tr bgcolor="#e4e4e4">
   <td>
-    <a name="cmdunmount"><h2>2.27 Unmount a File System (umount)</h2></a>
+    <a name="cmdunmount"><h2>2.28 Unmount a File System (umount)</h2></a>
   </td>
 </tr>
 </table>
@@ -1314,7 +1371,7 @@ nsh>
 <table width ="100%">
   <tr bgcolor="#e4e4e4">
   <td>
-    <a name="cmdunset"><h2>2.28 Unset an Environment Variable (unset)</h2></a>
+    <a name="cmdunset"><h2>2.29 Unset an Environment Variable (unset)</h2></a>
   </td>
   </tr>
 </table>
@@ -1340,7 +1397,7 @@ nsh&gt;
 <table width ="100%">
   <tr bgcolor="#e4e4e4">
   <td>
-    <a name="cmdusleep"><h2>2.29 Wait for Microseconds (usleep)</h2></a>
+    <a name="cmdusleep"><h2>2.30 Wait for Microseconds (usleep)</h2></a>
   </td>
   </tr>
 </table>
@@ -1448,7 +1505,11 @@ usleep &lt;usec&gt;
   </tr>
   <tr>
     <td><b><code>mkfifo</code></b></td>
-    <td>!<code>CONFIG_DISABLE_MOUNTPOINT</code> && <code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0</td>
+    <td><code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0</td>
+  </tr>
+  <tr>
+    <td><b><code>mkrd</code></b></td>
+    <td>!<code>CONFIG_DISABLE_MOUNTPOINT</code> && <code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0 && <code>CONFIG_FS_FAT</code></td>
   </tr>
   <tr>
     <td><b><code>mount</code></b></td>
@@ -1711,6 +1772,7 @@ usleep &lt;usec&gt;
   <li><a href="#cmdmkdir"><code>mkdir</code></a></li>
   <li><a href="#cmdmkfatfs"><code>mkfatfs</code></a></li>
   <li><a href="#cmdmkfifo"><code>mkfifo</code></a></li>
+  <li><a href="#cmdmkrd"><code>mkrd</code></a></li>
   <li><a href="#cmdmount"><code>mount</code></a></li>
   <li><a href="#cmdoverview"><code>nice</code></a></li>
   <li><a href="#environvars"><code>OLDPWD</code></a></li>
diff --git a/nuttx/Documentation/NuttX.html b/nuttx/Documentation/NuttX.html
index 2e936dee9..59f2afdf9 100644
--- a/nuttx/Documentation/NuttX.html
+++ b/nuttx/Documentation/NuttX.html
@@ -8,7 +8,7 @@
   <tr align="center" bgcolor="#e4e4e4">
     <td>
       <h1><big><font color="#3c34ec"><i>NuttX RTOS</i></font></big></h1>
-      <p>Last Updated: September 5, 2008</p>
+      <p>Last Updated: September 6, 2008</p>
     </td>
   </tr>
 </table>
@@ -1078,6 +1078,8 @@ nuttx-0.3.14 2008-xx-xx Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;
 	* NSH: Created an HTML document and a more detailed README file describing NSH.
 	* Added basic TFTP client logic (netutils/tftpc).  Untested as of initial check-in.
 	* NSH: Add get and put commands to support TFTP get and put operations.
+	* NSH: Added a mkrd command that will create a RAMDISK that can be formatted
+	  and mounted.
 
 pascal-0.1.3 2008-xx-xx Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;
 
diff --git a/nuttx/arch/arm/src/common/up_exit.c b/nuttx/arch/arm/src/common/up_exit.c
index 2660ed80b..79ff21218 100644
--- a/nuttx/arch/arm/src/common/up_exit.c
+++ b/nuttx/arch/arm/src/common/up_exit.c
@@ -78,21 +78,21 @@ static void _up_dumponexit(FAR _TCB *tcb, FAR void *arg)
   int i;
 #endif
 
-  dbg("  TCB=%p name=%s\n", tcb, tcb->argv[0]);
+  sdbg("  TCB=%p name=%s\n", tcb, tcb->argv[0]);
 
 #if CONFIG_NFILE_DESCRIPTORS > 0
   if (tcb->filelist)
     {
-      dbg("    filelist refcount=%d\n",
-          tcb->filelist->fl_crefs);
+      sdbg("    filelist refcount=%d\n",
+           tcb->filelist->fl_crefs);
 
       for (i = 0; i < CONFIG_NFILE_DESCRIPTORS; i++)
         {
           struct inode *inode = tcb->filelist->fl_files[i].f_inode;
           if (inode)
             {
-              dbg("      fd=%d refcount=%d\n",
-                  i, inode->i_crefs);
+              sdbg("      fd=%d refcount=%d\n",
+                   i, inode->i_crefs);
             }
         }
     }
@@ -101,8 +101,8 @@ static void _up_dumponexit(FAR _TCB *tcb, FAR void *arg)
 #if CONFIG_NFILE_STREAMS > 0
   if (tcb->streams)
     {
-      dbg("    streamlist refcount=%d\n",
-          tcb->streams->sl_crefs);
+      sdbg("    streamlist refcount=%d\n",
+           tcb->streams->sl_crefs);
 
       for (i = 0; i < CONFIG_NFILE_STREAMS; i++)
         {
@@ -110,11 +110,11 @@ static void _up_dumponexit(FAR _TCB *tcb, FAR void *arg)
           if (filep->fs_filedes >= 0)
             {
 #if CONFIG_STDIO_BUFFER_SIZE > 0
-              dbg("      fd=%d nbytes=%d\n",
-                  filep->fs_filedes,
+              sdbg("      fd=%d nbytes=%d\n",
+                   filep->fs_filedes,
                   filep->fs_bufpos - filep->fs_bufstart);
 #else
-              dbg("      fd=%d\n", filep->fs_filedes);
+              sdbg("      fd=%d\n", filep->fs_filedes);
 #endif
             }
         }
@@ -148,10 +148,10 @@ void _exit(int status)
 
   (void)irqsave();
 
-  lldbg("TCB=%p exitting\n", tcb);
+  slldbg("TCB=%p exitting\n", tcb);
 
 #if defined(CONFIG_DUMP_ON_EXIT) && defined(CONFIG_DEBUG)
-  lldbg("Other tasks:\n");
+  slldbg("Other tasks:\n");
   sched_foreach(_up_dumponexit, NULL);
 #endif
 
@@ -164,7 +164,7 @@ void _exit(int status)
    */
 
   tcb = (_TCB*)g_readytorun.head;
-  lldbg("New Active Task TCB=%p\n", tcb);
+  slldbg("New Active Task TCB=%p\n", tcb);
 
   /* Then switch contexts */
 
diff --git a/nuttx/arch/arm/src/common/up_initialize.c b/nuttx/arch/arm/src/common/up_initialize.c
index 0f70fcca5..583142ec0 100644
--- a/nuttx/arch/arm/src/common/up_initialize.c
+++ b/nuttx/arch/arm/src/common/up_initialize.c
@@ -75,12 +75,12 @@
 static void up_calibratedelay(void)
 {
   int i;
-  lldbg("Beginning 100s delay\n");
+  slldbg("Beginning 100s delay\n");
   for (i = 0; i < 100; i++)
     {
       up_mdelay(1000);
     }
-  lldbg("End 100s delay\n");
+  slldbg("End 100s delay\n");
 }
 #else
 # define up_calibratedelay()
diff --git a/nuttx/arch/arm/src/common/up_releasepending.c b/nuttx/arch/arm/src/common/up_releasepending.c
index 7f8016d53..44b36590f 100644
--- a/nuttx/arch/arm/src/common/up_releasepending.c
+++ b/nuttx/arch/arm/src/common/up_releasepending.c
@@ -76,7 +76,7 @@ void up_release_pending(void)
 {
   _TCB *rtcb = (_TCB*)g_readytorun.head;
 
-  lldbg("From TCB=%p\n", rtcb);
+  slldbg("From TCB=%p\n", rtcb);
 
   /* Merge the g_pendingtasks list into the g_readytorun task list */
 
@@ -101,7 +101,7 @@ void up_release_pending(void)
            */
 
           rtcb = (_TCB*)g_readytorun.head;
-          lldbg("New Active Task TCB=%p\n", rtcb);
+          slldbg("New Active Task TCB=%p\n", rtcb);
 
           /* Then switch contexts */
 
@@ -121,7 +121,7 @@ void up_release_pending(void)
            */
 
           rtcb = (_TCB*)g_readytorun.head;
-          lldbg("New Active Task TCB=%p\n", rtcb);
+          slldbg("New Active Task TCB=%p\n", rtcb);
 
            /* Then switch contexts */
 
diff --git a/nuttx/arch/arm/src/common/up_reprioritizertr.c b/nuttx/arch/arm/src/common/up_reprioritizertr.c
index 1f589b73f..130819582 100644
--- a/nuttx/arch/arm/src/common/up_reprioritizertr.c
+++ b/nuttx/arch/arm/src/common/up_reprioritizertr.c
@@ -97,7 +97,7 @@ void up_reprioritize_rtr(_TCB *tcb, ubyte priority)
       _TCB *rtcb = (_TCB*)g_readytorun.head;
       boolean switch_needed;
 
-      lldbg("TCB=%p PRI=%d\n", tcb, priority);
+      slldbg("TCB=%p PRI=%d\n", tcb, priority);
 
       /* Remove the tcb task from the ready-to-run list.
        * sched_removereadytorun will return TRUE if we just
@@ -149,7 +149,7 @@ void up_reprioritize_rtr(_TCB *tcb, ubyte priority)
                */
 
               rtcb = (_TCB*)g_readytorun.head;
-              lldbg("New Active Task TCB=%p\n", rtcb);
+              slldbg("New Active Task TCB=%p\n", rtcb);
 
               /* Then switch contexts */
 
@@ -168,7 +168,7 @@ void up_reprioritize_rtr(_TCB *tcb, ubyte priority)
                */
 
               rtcb = (_TCB*)g_readytorun.head;
-              lldbg("New Active Task TCB=%p\n", rtcb);
+              slldbg("New Active Task TCB=%p\n", rtcb);
 
               /* Then switch contexts */
 
diff --git a/nuttx/arch/arm/src/common/up_schedulesigaction.c b/nuttx/arch/arm/src/common/up_schedulesigaction.c
index 6b56cc3b6..1dbecc8e7 100644
--- a/nuttx/arch/arm/src/common/up_schedulesigaction.c
+++ b/nuttx/arch/arm/src/common/up_schedulesigaction.c
@@ -99,7 +99,7 @@ void up_schedule_sigaction(_TCB *tcb, sig_deliver_t sigdeliver)
 {
   /* Refuse to handle nested signal actions */
 
-  dbg("tcb=0x%p sigdeliver=0x%p\n", tcb, sigdeliver);
+  sdbg("tcb=0x%p sigdeliver=0x%p\n", tcb, sigdeliver);
 
   if (!tcb->xcp.sigdeliver)
     {
@@ -113,7 +113,7 @@ void up_schedule_sigaction(_TCB *tcb, sig_deliver_t sigdeliver)
        * being delivered to the currently executing task.
        */
 
-      dbg("rtcb=0x%p current_regs=0x%p\n", g_readytorun.head, current_regs);
+      sdbg("rtcb=0x%p current_regs=0x%p\n", g_readytorun.head, current_regs);
 
       if (tcb == (_TCB*)g_readytorun.head)
         {
diff --git a/nuttx/arch/arm/src/common/up_sigdeliver.c b/nuttx/arch/arm/src/common/up_sigdeliver.c
index 31d798b93..4b2f1c27b 100644
--- a/nuttx/arch/arm/src/common/up_sigdeliver.c
+++ b/nuttx/arch/arm/src/common/up_sigdeliver.c
@@ -90,8 +90,8 @@ void up_sigdeliver(void)
 
   up_ledon(LED_SIGNAL);
 
-  dbg("rtcb=%p sigdeliver=%p sigpendactionq.head=%p\n",
-       rtcb, rtcb->xcp.sigdeliver, rtcb->sigpendactionq.head);
+  sdbg("rtcb=%p sigdeliver=%p sigpendactionq.head=%p\n",
+        rtcb, rtcb->xcp.sigdeliver, rtcb->sigpendactionq.head);
   ASSERT(rtcb->xcp.sigdeliver != NULL);
 
   /* Save the real return state on the stack. */
@@ -124,7 +124,7 @@ void up_sigdeliver(void)
    * (it is probably EINTR).
    */
 
-  dbg("Resuming\n");
+  sdbg("Resuming\n");
   rtcb->pterrno = saved_errno;
 
   /* Then restore the correct state for this thread of
diff --git a/nuttx/examples/README.txt b/nuttx/examples/README.txt
index 138653653..ba6051e16 100644
--- a/nuttx/examples/README.txt
+++ b/nuttx/examples/README.txt
@@ -39,7 +39,7 @@ examples/mount
 ^^^^^^^^^^^^^^
 
   This contains a simple test of filesystem mountpoints.
-  
+
   * CONFIG_EXAMPLES_MOUNT_DEVNAME
       The name of the user-provided block device to mount.
       If CONFIG_EXAMPLES_MOUNT_DEVNAME is not provided, then
diff --git a/nuttx/examples/nsh/README.txt b/nuttx/examples/nsh/README.txt
index 1972b2b13..0c0bc2eba 100644
--- a/nuttx/examples/nsh/README.txt
+++ b/nuttx/examples/nsh/README.txt
@@ -325,6 +325,45 @@ o mkfifo <path>
      brw-rw-rw-       0 ram0
     nsh>
 
+o mkrd [-m <minor>] [-s <sector-size>] <nsectors>
+
+  Create a ramdisk consisting of <nsectors>, each of size
+  <sector-size> (or 512 bytes if <sector-size> is not specified.
+  The ramdisk will be registered as /dev/ram<n> (if <n> is not
+  specified, mkrd will attempt to register the ramdisk as
+  /dev/ram0.
+
+  Example:
+  ^^^^^^^^
+
+    nsh> ls /dev
+    /dev:
+     console
+     null
+     ttyS0
+     ttyS1
+    nsh> mkrd 1024
+    nsh> ls /dev
+    /dev:
+     console
+     null
+     ram0
+     ttyS0
+     ttyS1
+    nsh>
+
+  Once the ramdisk has been created, it may be formatted using
+  the mkfatfs command and mounted using the mount command.
+
+  Example:
+  ^^^^^^^^
+    nsh> mkrd 1024
+    nsh> mkfatfs /dev/ram0
+    nsh> mount -t vfat /dev/ram0 /tmp
+    nsh> ls /tmp
+    /tmp:
+    nsh>
+
 o mount -t <fstype> <block-device> <dir-path>
 
   The 'mount' command mounts a file system in the NuttX psuedo
@@ -543,7 +582,8 @@ Command Dependencies on Configuration Settings
   mem        ---
   mkdir      !CONFIG_DISABLE_MOUNTPOINT && CONFIG_NFILE_DESCRIPTORS > 0
   mkfatfs    !CONFIG_DISABLE_MOUNTPOINT && CONFIG_NFILE_DESCRIPTORS > 0 && CONFIG_FS_FAT
-  mkfifo     !CONFIG_DISABLE_MOUNTPOINT && CONFIG_NFILE_DESCRIPTORS > 0
+  mkfifo     CONFIG_NFILE_DESCRIPTORS > 0
+  mkrd       !CONFIG_DISABLE_MOUNTPOINT && CONFIG_NFILE_DESCRIPTORS > 0 && CONFIG_FS_FAT
   mount      !CONFIG_DISABLE_MOUNTPOINT && CONFIG_NFILE_DESCRIPTORS > 0 && CONFIG_FS_FAT
   ping       CONFIG_NET && CONFIG_NET_ICMP && CONFIG_NET_ICMP_PING  && !CONFIG_DISABLE_CLOCK && !CONFIG_DISABLE_SIGNALS
   ps         --
diff --git a/nuttx/examples/nsh/nsh.h b/nuttx/examples/nsh/nsh.h
index f468a264a..c69aa2342 100644
--- a/nuttx/examples/nsh/nsh.h
+++ b/nuttx/examples/nsh/nsh.h
@@ -284,6 +284,7 @@ extern int cmd_lbracket(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv);
 # ifndef CONFIG_DISABLE_MOUNTPOINT
     extern int cmd_mkdir(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv);
     extern int cmd_mkfifo(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv);
+    extern int cmd_mkrd(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv);
     extern int cmd_rm(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv);
     extern int cmd_rmdir(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv);
 #   ifdef CONFIG_FS_FAT
diff --git a/nuttx/examples/nsh/nsh_fscmds.c b/nuttx/examples/nsh/nsh_fscmds.c
index 458f1130e..cd02ca576 100644
--- a/nuttx/examples/nsh/nsh_fscmds.c
+++ b/nuttx/examples/nsh/nsh_fscmds.c
@@ -48,6 +48,7 @@
 #     include <sys/mount.h>
 #     include <nuttx/mkfatfs.h>
 #   endif
+#   include <nuttx/ramdisk.h>
 #endif
 #endif
 
@@ -756,7 +757,7 @@ int cmd_mkfatfs(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv)
  * Name: cmd_mkfifo
  ****************************************************************************/
 
-#if !defined(CONFIG_DISABLE_MOUNTPOINT) && CONFIG_NFILE_DESCRIPTORS > 0
+#if CONFIG_NFILE_DESCRIPTORS > 0
 int cmd_mkfifo(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv)
 {
   char *fullpath = nsh_getfullpath(vtbl, argv[1]);
@@ -776,6 +777,99 @@ int cmd_mkfifo(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv)
 #endif
 
 /****************************************************************************
+ * Name: cmd_mkrd
+ ****************************************************************************/
+
+#if !defined(CONFIG_DISABLE_MOUNTPOINT) && CONFIG_NFILE_DESCRIPTORS > 0
+int cmd_mkrd(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv)
+{
+  const char *fmt;
+  ubyte *buffer;
+  uint32 nsectors;
+  int sectsize = 512;
+  int minor = 0;
+  int ret;
+
+  /* Get the mount options */
+
+  int option;
+  while ((option = getopt(argc, argv, ":m:s:")) != ERROR)
+    {
+      switch (option)
+        {
+          case 'm':
+            minor = atoi(optarg);
+            if (minor < 0 || minor > 255)
+              {
+                fmt = g_fmtargrange;
+                goto errout_with_fmt;
+              }
+            break;
+
+          case 's':
+            sectsize = atoi(optarg);
+            if (minor < 0 || minor > 16384)
+              {
+                fmt = g_fmtargrange;
+                goto errout_with_fmt;
+              }
+            break;
+
+         case ':':
+            fmt = g_fmtargrequired;
+            goto errout_with_fmt;
+
+          case '?':
+          default:
+            fmt = g_fmtarginvalid;
+            goto errout_with_fmt;
+        }
+    }
+
+  /* There should be exactly on parameter left on the command-line */
+
+  if (optind == argc-1)
+    {
+      nsectors = (uint32)atoi(argv[optind]);
+    }
+  else if (optind >= argc)
+    {
+      fmt = g_fmttoomanyargs;
+      goto errout_with_fmt;
+    }
+  else
+    {
+      fmt = g_fmtargrequired;
+      goto errout_with_fmt;
+    }
+
+  /* Allocate the memory backing up the ramdisk */
+
+  buffer = (ubyte*)malloc(sectsize * nsectors);
+  if (!buffer)
+    {
+      fmt = g_fmtcmdoutofmemory;
+      goto errout_with_fmt;
+    }
+
+  /* Then register the ramdisk */
+
+  ret = rd_register(minor, buffer, nsectors, sectsize, TRUE);
+  if (ret < 0)
+    {
+      nsh_output(vtbl, g_fmtcmdfailed, argv[0], "rd_register", NSH_ERRNO_OF(-ret));
+      free(buffer);
+      return ERROR;
+    }
+  return ret;
+
+errout_with_fmt:
+  nsh_output(vtbl, fmt, argv[0]);
+  return ERROR;
+}
+#endif
+
+/****************************************************************************
  * Name: cmd_mount
  ****************************************************************************/
 
diff --git a/nuttx/examples/nsh/nsh_main.c b/nuttx/examples/nsh/nsh_main.c
index f2890159c..e58836fcc 100644
--- a/nuttx/examples/nsh/nsh_main.c
+++ b/nuttx/examples/nsh/nsh_main.c
@@ -163,6 +163,7 @@ static const struct cmdmap_s g_cmdmap[] =
   { "mkfatfs",  cmd_mkfatfs,  2, 2, "<path>" },
 #endif
   { "mkfifo",   cmd_mkfifo,   2, 2, "<path>" },
+  { "mkrd",     cmd_mkrd,     2, 6, "[-m <minor>] [-s <sector-size>] <nsectors>" },
 #endif
   { "mh",       cmd_mh,       2, 3, "<hex-address>[=<hex-value>][ <hex-byte-count>]" },
 #if !defined(CONFIG_DISABLE_MOUNTPOINT) && CONFIG_NFILE_DESCRIPTORS > 0