Need to enable SDIO DMA

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@2285 42af7a65-404d-4744-a932-0658087f49c3

README.txt

 README
 ^^^^^^
 
+  o Installation
   o Configuring NuttX
   o Building NuttX
   o Documentation
 
+INSTALLATION
+^^^^^^^^^^^^
+
+Download and unpack the NuttX tarball.  If you are reading this, then you
+have probably already done that.  After unpacking, you will end up with a
+directory called nuttx-version (where version is the NuttX version number).
+You might want to rename that directory nuttx to match the various instructions
+in the documentation and some scripts in the source tree.
+
+That nuttx build directory should reside in a path that contains no spaces
+in the higher level directory names.  For example, under Cygwin, your home
+directory might be formed from your first and last names like: "/home/First Last".
+That will cause strange errors when the make system tries to build.
+
 CONFIGURING NUTTX
 ^^^^^^^^^^^^^^^^^
 

configs/stm3210e-eval/nsh/defconfig

@@ -499,7 +499,7 @@ CONFIG_FS_WRITEBUFFER=n
 # CONFIG_MMCSD_HAVECARDDETECT
 #   SDIO driver card detection is 100% accurate
 #
-CONFIG_SDIO_DMA=n
+CONFIG_SDIO_DMA=y
 CONFIG_MMCSD_MMCSUPPORT=n
 CONFIG_MMCSD_HAVECARDDETECT=n