system/usbmsc
^^^^^^^^^^^^^^^
This add-on registers a block device driver, then exports the block
the device using the USB storage class driver. In order to use this
add-on, your board-specific logic must provide the function:
void board_usbmsc_initialize(void);
This function will be called by the system/usbmsc indirectly via the
boarctl BOARDIOC_USBDEV_CONTROL command in order to do the actual
registration of the block device drivers. For examples of the
implementation of board_usbmsc_initialize() see
configs/mcu123-lpc124x/src/up_usbmsc.c or
configs/stm3210e-eval/src/usbmsc.c
Configuration options:
CONFIG_NSH_BUILTIN_APPS
This add-on can be built as two NSH "built-in" commands if this option
is selected: 'msconn' will connect the USB mass storage device; 'msdis'
will disconnect the USB storage device.
CONFIG_LIB_BOARDCTL
Enables the boardctl() interfaces.
CONFIG_BOARDCTL_USBDEVCTRL
Enables the BOARDIOC_USBDEV_CONTROL boardctl() command.
CONFIG_SYSTEM_USBMSC_NLUNS
Defines the number of logical units (LUNs) exported by the USB storage
driver. Each LUN corresponds to one exported block driver (or partition
of a block driver). May be 1, 2, or 3. Default is 1.
CONFIG_SYSTEM_USBMSC_DEVMINOR1
The minor device number of the block driver for the first LUN. For
example, N in /dev/mmcsdN. Used for registering the block driver. Default
is zero.
CONFIG_SYSTEM_USBMSC_DEVPATH1
The full path to the registered block driver. Default is "/dev/mmcsd0"
CONFIG_SYSTEM_USBMSC_DEVMINOR2 and CONFIG_SYSTEM_USBMSC_DEVPATH2
Similar parameters that would have to be provided if CONFIG_SYSTEM_USBMSC_NLUNS
is 2 or 3. No defaults.
CONFIG_SYSTEM_USBMSC_DEVMINOR3 and CONFIG_SYSTEM_USBMSC_DEVPATH3
Similar parameters that would have to be provided if CONFIG_SYSTEM_USBMSC_NLUNS
is 3. No defaults.
CONFIG_SYSTEM_USBMSC_DEBUGMM
Enables some debug tests to check for memory usage and memory leaks.
If CONFIG_USBDEV_TRACE is enabled (or CONFIG_DEBUG_FEATURES and CONFIG_DEBUG_USB), then
the code will also manage the USB trace output. The amount of trace output
can be controlled using:
CONFIG_SYSTEM_USBMSC_TRACEINIT
Show initialization events
CONFIG_SYSTEM_USBMSC_TRACECLASS
Show class driver events
CONFIG_SYSTEM_USBMSC_TRACETRANSFERS
Show data transfer events
CONFIG_SYSTEM_USBMSC_TRACECONTROLLER
Show controller events
CONFIG_SYSTEM_USBMSC_TRACEINTERRUPTS
Show interrupt-related events.
Error results are always shown in the trace output
NOTE 1: When built as an NSH add-on command (CONFIG_NSH_BUILTIN_APPS=y),
Caution should be used to assure that the SD drive (or other storage device) is
not in use when the USB storage device is configured. Specifically, the SD
driver should be unmounted like:
nsh> mount -t vfat /dev/mmcsd0 /mnt/sdcard # Card is mounted in NSH
...
nsh> umount /mnd/sdcard # Unmount before connecting USB!!!
nsh> msconn # Connect the USB storage device
...
nsh> msdis # Disconnect USB storate device
nsh> mount -t vfat /dev/mmcsd0 /mnt/sdcard # Restore the mount
Failure to do this could result in corruption of the SD card format.
NOTE 2: This add-on used internal USB device driver interfaces. As such,
it relies on internal OS interfaces that are not normally available to a
user-space program. As a result, this add-on cannot be used if a
NuttX is built as a protected, supervisor kernel (CONFIG_BUILD_PROTECTED
or CONFIG_BUILD_LOADABLE).
