drivers/mtd/filemtd.c: Don't use file descriptors... Use the internal file system interfaces so that the loop device can be shared across threads.

drivers/loop: Don't use file descriptors... Use the internal file system interfaces so that the loop device can be shared across threads.

According to the specification, the close function must wait until all data
has been written before it closes the file (except O_NONBLOCK is set). The
maximum waiting time for this is not specified.

To be able to edit the file list of the process, the close function has to lock
the file list semaphore. After that the close function of the serial driver is
called.

Waiting for the complete transmission of all data is done in the serial driver.
This causes the semaphore to remain locked until all data has been sent.
However, no other thread of the process can edit the file list for that time
(open, close, dup2, etc.). This is not optimal in a multithreaded environment.
Therefore, we have to keep the waiting time within the driver as short as possible.

fs/userfs:  There are some deadlock issues that make the UserFS un-usable at the current time.  Added to the TODO list; also feature is now marked EXPERIMENTAL.

This commit modifies the Unix domain local socket design.  Local sockets are built on top of pipes.  The Local socket implementation maintained file descriptors to interrupt with the pipes.  File descriptors have the bad property that they are valid only while running on the thread within the task that created the local socket.

As a policy, all internal OS implementations must use "detached" files which are valid in any context and do not depend on the validity of a file descriptor at any point in time.  This commit converts the usage of file descriptors to detached files throughout the local socket implementation.

Squashed commit of the following:

    net/local: Finish change to eliminate use of file descriptors.
    net/local:  A little more of the conversion.
    net/local: Beginning of chnages to eliminate use of file descriptors in the local socket implementeation. poll() will be a problem.

ieee802154: Simplifies notify() and rxframe() calls to a single notify() call. dataind's and all other "notifs" are now "primitives" which aligns with standard terminology

* mac802154: Adds missing breaks from case statement

* sixlowpan: Fixes bad logic where ACK is not requested if address is not a broadcast

* ieee802154: Simplification of "notifs" and "datainds" to generic primitives passed via a single notify call to the layer above the MAC

* Directories.mk should reference CONFIG_WIRELESS instead of CONFIG_DRIVERS_WIRELESS

* xbee_netdev: Network must be locked when calling sixlowpan_input

* sixlowpan: Reassembly buffer can't be freed if provided by radio driver

* sixlowpan: Don't free IOB if there is an error processing it as the MAC will try to pass it along to another receiver

* ieee802154: Adds basic logging to ieee802154_primitive.c

* Minor fixes after rebase

* xbee: Adds AT query timeout to retry if XBee doesn't respond to request

* same70-xplained: Adds Xbee support. Makes mikroBus slot Kconfig 'choice'

* mac802154: Removes unused function declaration

* drivers/mrf24j40: Fixes compilation error using . operator rather than -> operator

* mac802154_device: Changes a few mac802154_primtive_free's to ieee802154_primitive_free() and changes notif to primitive in a couple places.

* mac802154: Adds promiscous mode logic to bypass parsing of incoming frames. MAC char device also checks for promiscous mode and passes whole frames including header and FCS to the application if promiscous mode is enabled.

* sixlowpan: Fixes logic to correctly check if packet is large enough to include header.  This would cause packets to be considered too small when they are sufficiently sized.

* sixlowpan: Fixes forwarding logic to use forwarding device rather than received device to look up destination link layer address

* net/ipforward: Fixes typo that caused build error when IP forwarding was enabled with CONFIG_NET_ICMPv6_NEIGHBOR enabled as well.

* configs/same70-xplained: Simple spelling fix

Approved-by: Gregory Nutt <gnutt@nuttx.org>

Update TODO for broken local socket feature; Add work around to UserFS for broken local socket feature.

 libc/userfs: Correct return value from dispatchers.  Should return zero on success, not the number of bytes sent.

drivers/wireless/ieee80211:  Fix typos and spelling errors as needed for Photon build.

Fixes a memory leak that is caused because the client message queue is not unlinked after the client disconnects from the NX server.

Fix GPIO operation of STMPE811 driver.

Fixed issues:
1. STMPE811_GPIO_DIR was defined for register name
   and later was redefined to be the pin direction mask
   for `stmpe811_gpioconfig`

   I decided to change register name to be STMPE811_GPIO_DIR_REG,
   and keep pin direction mask STMPE811_GPIO_DIR, so that any
   external code that already use this driver will be unchanged.

2. The STMPE811 register GPIO_DIR uses bit value 1 for output
   and 0 for input, but `stmpe811_gpioconfig` set the opposite.

3. The call to `stmpe811_gpiowrite` from inside of `stmpe811_gpioconfig`
   leaded to deadlock.

Approved-by: Gregory Nutt <gnutt@nuttx.org>

Fix DEBUGASSERT() issues with nxhello on lc823450-xgevk

* sched/task: Remove DEBUGASSERT in task_exitstatus() and task_groupexit()

* graphics: Change DEBUGASSERT condition in nx_runinstance()

Approved-by: Gregory Nutt <gnutt@nuttx.org>

    fs/userfs:  This completes coding of the UserFS client and of the UserFS feature in general.  This feature is being merged to main now because I believe it is innocuous.  It is, however, untesed.  The next step will be to develop a test case to verify the feature.
    fs/userfs:  Completes the request logic for the UserFS client.  Still need the logic that receives the responses.
    fs/userfs:  Completes coding for most of the server side of the user filesystem logic.
    fs/userfs:  Big design changes, simplications. Use Unix domain local sockets instead of message queues.  Easier to transfer big data in local sockets than message queues.  Remove character drvier 'factory' it is not necessary.
    fs/userfs:  Minor reparitioning; volume private info does not need to be held on the OS client side.
    libc/userfs:  Add some of the server side logic.
    fs/userfs:  Add some UserFS initialization logic.
    fs/userfs:  Add frame work for the UserFS proxy.  Remove all references to a block driver.  There is no block dricer... what was I thinking?
    fs/userfs: Add some initialization of the character driver, 'factory' device.
    fs/userfs:  Rename from fusefs to userfs to that we don't stomp on someone else's cool name.
    Add a header file describing the fusefs interface.

Fix stm32 dmacapable on f20xx

* Fixed build for STM32F20XX platforms when CONFIG_STM32_DMACAPABLE is enabled

* Fixed build for STM32F20XX platforms when CONFIG_STM32_DMACAPABLE is enabled

Approved-by: Gregory Nutt <gnutt@nuttx.org>

fs/procfs:  Restore a necessary chagne that was lost with commit 07f441ee

configs/mx1ads:  This commit removes board support for the mx1ads board.  That board support was never completed and I no longer even have the hardware.  The unfinished board support is still available in the Obsoleted repository if anyone would ever like to resurrect it.

drivers/net:  Remove the old, unfinished Crystal LAN driver.  I don't even have the hardware that it goes with anymore.

Master

* stm32: add ADC DMA support to STM32F33 configuration

* stm32f33xxx_adc.c: fix compilation if no DMA

* nucleo-f334r8: eliminate warning

* nucleo-f334r8: add highpri example configuration

Approved-by: Gregory Nutt <gnutt@nuttx.org>

Correct a problem that was causing an apparent directory to be reported as a file instead of a directory by opendir.

This happened after adding these three new procfs entries:

  fs/block
  fs/mount
  fs/usage

Of course, there is no directory fs in this case, only three files that have fs/ in their relative pathnames.  The logic was detecting that fs was the name of the enty to report, but it was then declaring that fs was a file (because fs/block is of type file).

This was fixed by adding a check for matching lenghts.  i.e., if strlen(fs) != strlen(fs/block), then report fs as a directory instead of a file.

    fs/mount:  Implements procfs /proc/fs/blocks and /proc/fs/usage files, replacing the NSH df command.
    fs/mount:  Implements procfs /proc/fs/mount file, replacing the NSH mount command when there are not arguments.
    fs/: Move prototype of foreach_mountpoint out of include/nuttx/fs/fs.h to fs/mount/mount.h.  Add framework for the mount procfs (initial commit is just a close of the net/route table procfs.

Port STM32F7 I2C driver to STM32L4

* arch/stm32l4: port STM32F7 I2C driver to STM32L4

    STM32L4 I2C driver is in work-in-progress state (plentiful of
    TODOs and #warnings) and lags many features found in more
    up-to-date STM32 I2C drivers. The peripheral on STM32F7 and
    STM32L4 are identical except for L4's 'wakeup from stop mode'
    flag and STM32F7's I2C driver is in more 'ready to use' state.

    Patch ports the STM32F7 I2C driver to STM32L4. The I2C clock
    configuration is kept the same as before (I2CCLK = PCLK1 80 Mhz)
    instead of switching to STM32F7 arch default that is I2CCLK=HSI.
    Further work would be to add configuration option for choosing
    I2C clock source instead of current hard-coded default.

* arch/arm/stm32f7: i2c: restore bus frequency after I2C reset

    Copy frequency restoration fix from STM32L4 I2C driver to STM32F7 I2C driver.

* arch/arm/stm32f7: i2c: remove unused Kconfig option

* configs/nucleo-l496zg/nsh: enable I2C4 bus with i2ctool

Approved-by: Gregory Nutt <gnutt@nuttx.org>

Olimex stm32-h407 serial support for the on-board UEXT connector (fixed style & defconfig)

* olimex-stm32-h407: Add USART6 for UEXT connector.

* olimex-stm32-h407: nsh_uext configuration and README update.

Approved-by: Gregory Nutt <gnutt@nuttx.org>