Add Block-to-character device driver

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@1237 42af7a65-404d-4744-a932-0658087f49c3

ChangeLog

@@ -550,4 +550,6 @@
 	* Each NSH command can not be disabled through a configuration setting. All of these
           settings make the configuration of NSH potentially complex but also allow it to squeeze
           into very small memory footprints.
+	* Added a block to character (BCH) driver.  This is kind of the reverse of the loop
+	  device; it allows you access a block device like a character device.
 

Documentation/NuttX.html

@@ -1193,6 +1193,8 @@ nuttx-0.3.18 2008-xx-xx Gregory Nutt <spudmonkey@racsa.co.cr>
 	* Each NSH command can not be disabled through a configuration setting. All of these
           settings make the configuration of NSH potentially complex but also allow it to squeeze
           into very small memory footprints.
+	* Added a block to character (BCH) driver.  This is kind of the reverse of the loop
+	  device; it allows you access a block device like a character device.
 
 pascal-0.1.3 2008-xx-xx Gregory Nutt <spudmonkey@racsa.co.cr>
 

drivers/Makefile

@@ -53,7 +53,16 @@ ROOTDEPPATH	= --dep-path .
 MMCSDDEPPATH	= --dep-path mmcsd
 CFLAGS		+= ${shell $(TOPDIR)/tools/incdir.sh "$(CC)" $(TOPDIR)/drivers/mmcsd}
 
-ASRCS		= $(NET_ASRCS) $(USBDEV_ASRCS) $(MMCSD_ASRCS)
+ifneq ($(CONFIG_NFILE_DESCRIPTORS),0)
+ifneq ($(CONFIG_DISABLE_MOUNTPOINT),y)
+include bch/Make.defs
+ROOTDEPPATH	= --dep-path .
+BCHDEPPATH	= --dep-path bch
+CFLAGS		+= ${shell $(TOPDIR)/tools/incdir.sh "$(CC)" $(TOPDIR)/drivers/bch}
+endif
+endif
+
+ASRCS		= $(NET_ASRCS) $(USBDEV_ASRCS) $(MMCSD_ASRCS) $(BCH_ASRCS)
 AOBJS		= $(ASRCS:.S=$(OBJEXT))
 
 CSRCS		=
@@ -64,7 +73,7 @@ ifneq ($(CONFIG_DISABLE_MOUNTPOINT),y)
 CSRCS           += ramdisk.c
 endif
 endif
-CSRCS		+= $(NET_CSRCS) $(USBDEV_CSRCS) $(MMCSD_CSRCS)
+CSRCS		+= $(NET_CSRCS) $(USBDEV_CSRCS) $(MMCSD_CSRCS) $(BCH_CSRCS)
 COBJS		= $(CSRCS:.c=$(OBJEXT))
 
 SRCS		= $(ASRCS) $(CSRCS)
@@ -72,7 +81,7 @@ OBJS		= $(AOBJS) $(COBJS)
 
 BIN		= libdrivers$(LIBEXT)
 
-VPATH		= net:usbdev:mmcsd
+VPATH		= net:usbdev:mmcsd:bch
 
 all:	$(BIN)
 
@@ -88,7 +97,7 @@ $(BIN):	$(OBJS)
 	done ; )
 
 .depend: Makefile $(SRCS)
-	@$(MKDEP) $(ROOTDEPPATH) $(NETDEPPATH) $(USBDEVDEPPATH) $(MMCSDDEPPATH) \
+	@$(MKDEP) $(ROOTDEPPATH) $(NETDEPPATH) $(USBDEVDEPPATH) $(MMCSDDEPPATH) $(BCHDEPPATH) \
 	  $(CC) -- $(CFLAGS) -- $(SRCS) >Make.dep
 	@touch $@
 

include/nuttx/fs.h

@@ -370,8 +370,28 @@ EXTERN int lib_flushall(FAR struct streamlist *list);
  * subdirectory
  */
 
+/* Register /dev/null */
+
 EXTERN void devnull_register(void);
-EXTERN int losetup(const char *name, int minor, uint16 sectsize);
+
+/* Setup the loop device so that it exports the file referenced by 'filename'
+ * as a block device.
+ */
+
+EXTERN int losetup(const char *devname, const char *filename, uint16 sectsize,
+                   off_t offset, boolean readonly);
+EXTERN int loteardown(const char *devname);
+
+/*   Setup so that the block driver referenced by 'blkdev' can be accessed
+ *   similar to a character device.
+ */
+
+EXTERN int bchdev_register(const char *blkdev, const char *chardev, boolean readonly);
+EXTERN int bchdev_unregister(const char *chardev);
+EXTERN int bchlib_setup(const char *blkdev, boolean readonly, FAR void **handle);
+EXTERN int bchlib_teardown(FAR void *handle);
+EXTERN ssize_t bchlib_read(FAR void *handle, FAR char *buffer, size_t offset, size_t len);
+EXTERN ssize_t bchlib_write(FAR void *handle, FAR const char *buffer, size_t offset, size_t len);
 
 #undef EXTERN
 #if defined(__cplusplus)

include/nuttx/ioctl.h

@@ -53,8 +53,9 @@
  */
 
 #define _FIOCBASE       (0x8700) /* File system ioctl commands */
-#define _BIOCBASE       (0x8800) /* Block driver ioctl commands */
+#define _DIOCBASE       (0x8800) /* Character driver ioctl commands */
-#define _SIOCBASE       (0x8900) /* Socket ioctl commandss */
+#define _BIOCBASE       (0x8900) /* Block driver ioctl commands */
+#define _SIOCBASE       (0x8a00) /* Socket ioctl commandss */
 
 /* Macros used to manage ioctl commands */
 
@@ -69,10 +70,25 @@
 #define _FIOCVALID(c)   (_IOC_TYPE(c)==_FIOCBASE)
 #define _FIOC(nr)       _IOC(_FIOCBASE,nr)
 
-#define FIOC_MMAP       _FIOC(0x0001)  /* IN:  None
+#define FIOC_MMAP       _FIOC(0x0001)  /* IN:  Location to return address (void **)
                                         * OUT: If media is directly acccesible,
                                         *      return (void*) base address
-                                        *      of file */
+                                        *      of file
+                                        */
+/* NuttX file system ioctl definitions */
+
+#define _DIOCVALID(c)   (_IOC_TYPE(c)==_DIOCBASE)
+#define _DIOC(nr)       _IOC(_DIOCBASE,nr)
+
+#define DIOC_GETPRIV    _DIOC(0x0001)  /* IN: Location to return handle (void **)
+                                        * OUT: Reference to internal data
+                                        *      structure.  May have a reference
+                                        *      incremented.
+                                        */
+#define DIOC_RELPRIV    _DIOC(0x0003)  /* IN: None
+                                        * OUT: None, reference obtained by
+                                        *      FIOC_GETPRIV released.
+                                        */
 
 /* NuttX block driver ioctl definitions */