NuttX-7.17 Release Notes

The 117th release of NuttX, Version 7.17, was made on July 25, 2016, and is available for download from the website. Note that release consists of two tarballs: nuttx-7.17.tar.gz and apps-7.17.tar.gz. These are available from:

Both may be needed (see the top-level nuttx/README.txt file for build information).

Additional new features and extended functionality:

* File System and Block and MTD Drivers:

  - drivers/mtd: Add a driver of IS25xP SPI flash devices.  Based on
    sst25xx driver.  From Marten Svanfeldt.

* Networking and Network Drivers:

  - Break out internal interface psock_ioctl().

* Common Device Drivers:

  - PTYs: Added support for pseduo-terminals: Device drivers that can be
    used for communications between tasks (usually with re-directed I/O).
    Based on existing pipe logic.
  - Button upper half driver:  Added support for poll().
  - CAN:  Add support for poll. From Paul Alexander Patience.
  - GPIO:  Add support for a simple GPIO driver.  It supports only pre-
    configured input, output, and interrupting pins with basic input and
    output operations.  Interrupt events can lead to notification via a
  - I/O Expander: Shadow-Mode: The output- and configuration registers of
    the IO-Expander are held in the microcontrollers memory and only
    written to the IO-Expander.  This reduces bus traffic and is more
    error-proof than the normal read-modify-write operation. Retry Mode:
    If enabled and an error occurs while writing to the IO-Expander the
    current transmission is automatically repeated once. From Michael
  - Pipes/FIFOs:  Add support to allocating different sizes for pipe and
    fifo buffers.  Adds mkfifo2() and pipe2() which are just like mkfifo()
    and pipe(), but allow control of the size of the underlying, in-memory
    circular buffer.  Move pipe() and mkpipe() to the C library, they are
    no longer core OS interfaces.  Capability currenty used only by PTY
    logic to support, configurable, smaller buffers for PTYs.

* SYSLOG/Debug Output:

  - SYSLOG: Consolidated all SYSLOG logic in drivers/syslog.  Added an
    abstraction layer that supports:  (1) redirection of SYSLOG outpout.
    This is usually so that you can boot with one SYSLOG output but
    transition to another SYSLOG output when the OS has initialialized,
    (2) adds common serialization of interrupt output as a configuration
    option.  Without this configuration setting, interrupt level output
    will be asynchronous.  And (3) vsyslog is now a system call and is
    usable with other-than-FLAT builds.
  - SYSLOG: syslog() will now automatically redirect output to
    lowsyslog() if called from an interrupt handler.
  - Extended SYSLOG logic so that we can send SYSLOG output to a file.
  - SYSLOG character device channel will now expand LF to CR-LF.
    Controllable with a configuration option.
  - Add a SYSLOG character device that can be used to re-direct output
    to the SYSLOG channel (Not be be confused the the SYSLGO output to a
    character device).
  - Debug features are now enabled separately from debug output.
    (1) CONFIG_DEBUG is gone. It is replaced with CONFIG_DEBUG_FEATURES.
    (2) The macros dbg() and vdbg() have renamed as _err() and _info(),
    respectively. This also applies to all of the variants as well,
    XXdbg() and XXvdbg().  (3) Add a new debug level, _warn() (and
    all variants XXwarn(), XXvwarn(), etc.). (4) Debug assertions can
    now be enabled separately from debug output. (5) You can now enable
    subsystem/device driver debug output at different output levels. For
    example, CONFIG_DEBUG_FS no longer enables file system debug output
    It enables general file system debug logic and enables selection of
  - Since the SYSLOG layer now automatically handles low-level vs.
    high-level output, the low-level (ll) variants of the debug macros
    were eliminated.
  - Reviewed all uses of *err().  These macro family should indicate
    only error conditions.  Convert *err() to either *info() or add
    ERROR:, depending on if an error is reported.
  - _alert(): New debug macro: _alert().  This is high priority,
     unconditional output and is used to simplify and standardize crash
     error reporting.
  - Many CONFIG_DEBUG_* options did not have matching macros defined in
    include/debug.h.  Rather, there were various definitions scattered
    throughout the sourse tree.  These were collected together and
    centralized with single macro definitions in include/debug.h

* Simulation Platform:

  - Added the simulated QSPI (N25Q) flash to the simulation and extened
    flash simulation capabilities to run with MTD drivers based on config
    options (currently m25p, sst26 and w25). From Ken Pettit.

* Atmel SAMV7 Drivers:

  - SPI: SPI-Freq. 40MHz; VARSELECT; hw-features This change adds the
    following improvements:

      o Increase the allowed SPI-Frequency from 20 to 40 MHz.
      o Correct and rename the "VARSELECT" option   This option was
        included in the code as "CONFIG_SPI_VARSELECT" but nowhere
        defined in a Kconfig file. The change renames it to
        "CONFIG_SAMV7_SPI_VARSELECT" and corrects the implementation
        according the datasheet of Atmel. In short, this option
        switches the processor from "fixed peripheral selection"
        (single device) to "variable peripheral selection" (multiple
        devices on the bus).
      o Add a new Function to the interface to control the timing and
        delays of the chip according the ChipSelect lines. This function
        can control the delay between the assertion of the ChipSelect and
        the first bit, between the last bit and the de-assertion of the
        ChipSelect and between two ChipSelects. This is needed to tune
        the transfer according the specification of the connected devices.
      o Add three "hw-features" for the SAMV7, which controls the behavior
        of the ChipSelect:
          - force CS inactive after transfer: this forces a (short) de-
            assertion of the CS after a transfer, even if more data is
            available in time
          - force CS active after transfer: this forces the CS to stay
            active after a transfer, even if the chip runs out of data.
            Btw.: this is a prerequisit to make the LASTXFER bit working
            at all.
          - escape LASTXFER: this suppresses the LASTXFER bit at the end
            of the next transfer. The "escape"-Flag is reset automatically.

    From Frank Benkert
  - TWISHS:  Driver improvements from Michael Spahlinger.
  - GPIO-Driver fixed for Open-Drain Pins:

      o sam_gpioread: Now the actual line level from the pin is read
        back.   This is extremely important for Open-Drain Pins, which
        can be used bidirectionally
      o Re-Implemented twi_reset-function and enhanced it so it can be
        called from inside the driver (see next point)
      o Glitch-Filter: Added a configuration option to enable the twi-
        built-in glitch filter
      o Added a "Single Master Mode": In EMC Testing the TWI-Bus got
        stuck because the TWI-Master detected a Multi-Master access (but
        there is no second master). With the option "Single Master" we
        detect these events and automatically trigger a twi_reset. We
        also do an automatic recovery if a slave got stuck (SDA stays

    With the above changes I²C-Bus reliability in harsh environments (eg.
    EMC) is greatly improved. The small change in the GPIO-Driver was
    necessary because otherwise you cannot read back the correct line
    status of Open-Drain Outputs and this is needed by the twi_reset
    function.  From Michael Spahlinger

* NXP Freescale LPC43xx Drivers:

  - EMC: Extend LPC43xx EMC code to support SDRAM on a dynamic memory
    interface.  From Vytautas Lukenskas.

* NXP Freescale Kinetis:

  - Kinetis K64:  Add basic support for the K64 family.  I leveraged the
    changes from and merged
    into the existing kinetis code  with a lot of changes and additions
    (like pin multiplexing definitions).

* NXP Freescale Kinetis Drivers:

  - Add a Kinetis USB device controller driver.  Derived from the pic32mx
    usb driver, which uses the same usb controller.  From kfazz.
  - Kinetis pwm support, based on the KL pwm driver.  From kfazz.
  - Kinetis Ethernet:  Add support for the KSZ8081 PHY.
  - Kinetis Ethernet:  Modified Ethernet driver to try all PHY addresses
    and then only fail if the driver cannot find a usable PHY address.
    This means that you no longer have to specific the PHY address in
  - Kinetis Ethernet:  Add support for CONFIG_NET_NOINTS.  The driver no
    longer runs the networking at interrupt level but can defer interrupt
    work to the high-priority work queue.

* NXP Freescale Kinetis Boards:

  - Teensy-3.x:  Add USB support and a usbnsh configuration.
    From kfazz (2016-06).
  - Freedom-K64F: Add support for the NXP Freedom-K64F board at 120MHz.
    This is primarily the work of Jordan Macintyre.  I leveraged this
    code from which was, itself,
    a leverage from the old K60 TWR configuration.  This includes
    significant corrections (LEDs, buttons, README, etc) and extensions
    and updates to match more recent BSPs.
  - Freedom-K64F:  Added a configuration that supports networking.

* STMicro STM32:

  - STM32 F1-4: Added support for the STM32F105R.  From Konstantin
  - STM32 F4: Added support for the STM32F76xxx and STM32F77xx
    families. From David Sidrane.
  - STM32 F1-4:  Add support for Tickless mode (two timer
    implementation).  From Max Neklyudov.
  - STM32 L4: Add support for tickless OS, and incidentally timers,
    PWM, oneshot, free-running....  From ziggurat29.

* STMicro STM32 Drivers:

  - STM32 F1-4: Add the up_getc() function to STM32 in order to support
    the minnsh configuration.  From Alan Carvalho de Assis.
  - STM32 F7: Add SPI driver.  From David Sidrane.
  - STM32 F7: Add SPI, I2C, and ADC drivers.  From Lok Tep.
  - STM32 L4: Add ioctls to set/get CAN bit timing in stm32l4.  Add
    ioctl hooks to allow future management of can id filters. From
    Sebastien Lorquet.
  - STM32 L4: Add some CAN mode IOCTL calls.  These will be useful for
    device autotest when the application boots.  They are redundant
    with the CONFIG_CAN_LOOPBACK option, which can now just be
    interpreted as a default setting.  From Sebastien Lorquet.
  - STM32 F1-4: Port STM32L4 CAN IOCTLs to STM32.  From Sebastien Lorquet.
  - STM32 L4: Implementation of loopback IOCTLs.  From Sebastien
  - STM32 F7: Added SDMMC1 support for stm32F7 74-75.  From Lok Tep.
  - STM32 F7: Add USB support.  From Lok Tep.
  - STM32 F7: Added PWR, RTC, and BBSRAM support for stm32f7. From David
  - STM32 F7: Added STMF7xxx RTC.  From David Sidrane.
  - STM32 F7: Added STM32F7 DBGMCU.  From David Sidrane.
  - STM32 L4: Port support for both RX FIFOs from STM32 CAN.  From Paul
    Alexander Patience.

* STMicro STM32 Boards:

  - Added a minnsh configuration for the STM32F103-Minimum board.  From
    Alan Carvalho de Assis .
  - Added support for the Nucleo-F767ZI board. From David Sidrane.
  - Nucleo-144/Nucleo-F767ZI:  Add test for STM32 F7 SPI.  From David
  - Nucleo-144: Added SDMMC support to Nucleo-144. From David Sidrane.
  - Olimex STM32-E407:  Add support for Olimex STM32 E407 board.  From
    Mateusz Szafoni.
  - Nucleo-144: Added USB OTG device to Nucleo-144.  From David Sidrane.
  - Nucleo-144: Added bbsram test to Nucleo-144.  From David Sidrane.
  - STM32F4 Discovery: add CAN support for STM32F4 Discovery.  From
    Matthias Renner.
  - STM32F4 Discovery:  added a canard configuration files.  From
    Matthias Renner.
  - STM32F4 Discovery: Add FPU support for ostest for the STM32F4
    Discovery platform. From David Alessio.
  - STM32L476 Discovery: Update stm32l476 disco to include init code for
    smartfs and nxffs for cases where those fs are included in build.
    From ziggurat29.

* C Library/Header Files:

  - include/assert.h: Check if NDEBUG is defined.  From Paul Alexander
  - assert.h: Define static assert for C++ usage.  From Paul Alexander
  - Add crc64 support. From  Paul Alexander Patience.
  - hex2bin:  Move the portable library portion of apps/system/hex2bin
    the C library with the OS internals.  It is used in certain internal
    boot-loader builds.
  - Add raise().
  - libm: This change should significantly improve the performance of
    single precision floating point math library functions. The vast
    majority of changes have to do with preventing the compiler from
    needlessly promoting floats to doubles, performing the calculation
    with doubles, only to demote the result to float. These changes only
    affect the math lib functions that return float. From David Alessio.
  - printf(): If there are no streams, let printf() fall back to use
    syslog() for output.
  - Move pipe() and mkpipe() to nuttx/libc, they are no
    longer core OS interfaces.  Capability currenty used only by PTY logi
    to support, configurable, smaller buffers for PTYs.
  - Move driver-related files from include/nuttx to include/nuttx/drivers.
    Move driver related prototypes out of include/nuttx/fs/fs.h and into
    new include/drivers/drivers.h.
  - include /nuttx/lib: Move library-related files from include/nuttx to

* Build/Configuration System:

  - Custom Board Configuration: Add logic to support custom board
    directories that include a Kconfig file.  During the context phase
    of the build, any Kconfig file in the custom board directory is
    copied into configs/dummy, replacing the existing Kconfig file with
    the target Kconfig file.
  - Remove the includes/apps link to apps/include.  It is no longer
    used.  From Sebastien Lorquet.

* Tools:

  - tools/ will now build NxWM configurations.

* Appplication Build/Configuration System:

  - Change to the way that apps/ Kconfig files are generated in
    order to better support reuse of the apps/ directory in NuttX
    products.  Changes include: Make the full tree use wildcards
    make.defs, Add empty preconfig rules to 'leaf' makefiles, Use for recursive dir makefiles, Individual app kconfig
    fixes, Recursive Kconfig autogeneration, Add kconfig files for
    pcode and tiff, and fix a gitignore rule,  From Sébastien Lorquet.
  - apps/include directory structure reorganized.  There are no longer
    any header files in the apps/include/. directory.  Rather, sub-
    directories were added to match the partitioning of apps/ sub-
    directories and the header files were moved into the appropriate
    sub-directory.  This change is intended to help with some changes
    being considered by Sébastien Lorquet.
  - Call all includes from <apps/bla/bla.h> to "bla/bla.h". From Sebastien
  - Add apps/include to include path in top-level Make.defs file.

* Applications: apps/nshlib:

  - Make NSH net-initialization be a configuration option. From Marten
  - Add NTP client initialization in NSH network startup logic.  From
    David S. Alessio .
  - 'ps' command now prints out the stack usage if stack coloration is
    enabled.  From Frank Benkert.
  - Allow stack usage to be disabled on constrained systems. From David

* Applications: apps/netutils:

  - NTP Client:  Add retries.  From David S. Alessio.
  - NTP Client:  The NTP client will now optionally use as
    the NTP server; and reset the retry count upon success -- more robust.
    From David Alessio.
  - ESP8266: Add logic to set the BAUD rate.  From Pierre-noel Bouteville.
  - ESP8266: In Kconfig, select ARCH_HAVE_NET when NETUTILS_ESP8266 is
    selected.  This allows, among other things, support for network debug
    output.  From Pierre-noel Bouteville.

* Applications: apps/fsutils:

  - flash_eraseall: IOCTL wrapper for MDCIO_BULKERASE command.   Was in
    nuttx/drivers/mtd.  Moved to apps/fsutils because the call directly into
    the OS was incorrect.

* Applications: apps/canutils:

  - canlib: Basic CAN utility library. From Sebastien Lorquet.

* Platforms: apps/system:

  - flash_eraseall: Now uses the IOCTL wrapper at apps/fsutils/flash_eraseall.

* Platforms: apps/platform:

  - Add platform files for Olimex STM32 E407.  From Mateusz Szafoni.

* Applications: apps/examples:

  - apps/examples/canard:  Add canard example application.  From
    Matthias Renner.
  - apps/examples/pty_test: PTY test program.  From Alan Carvalho de


* IEEE802.14.5/6LowPAN.  Hooks and framework for this effort were
  introduced in NuttX-7.15.  Work has continued on this effort on
  forks from the main repositories, albeit with many interruptions.
  The completion of this wireless feature will postponed until at
  least NuttX-7.18.

* i.MX6 SMP.  Partially functional, but there is more that still
  needs to be done.

Bugfixes. Only the most critical bugfixes are listed here (see the ChangeLog for the complete list of bugfixes and for additional, more detailed bugfix information):

* Core OS:

  - semaphores: Need to set errno to EINVAL on errors in sem_post()
    and sem_wait(). From Paul Alexander Patience.

* File System/Block Drivers/MTD Drivers:

  - Several MTD FLASH drivers nullify the freed 'priv' structure and
    failed to return NULL as stated in the comments. Result, will
    operate on a NULL pointer later.  Noted by David Sidrane.
  - VFS ioctl().  Per comments from David Sidrane, file_ioctl() should
    not return succeed if the ioctl method is not supported.  It
    probably should return ENOTTY in that case.
  - SST26 Driver: Before accessing the sst26 flash, the "Global Unlock"
    command must me executed, which I do in the sst26 driver.  BUT re-
    reading the datasheet, the WREN instruction is required to enable
    the execution of this command. This was not done. I have no idea how
    the driver currently works except by chance. The writes should never
    happen at all, the flash is half-enabled!  From Sebastien Lorquet.
  - N25Qxx Driver: Alter the notion of 'blocksize' to be equivalent to
    'flash write page size' in order to align with assumptions in the
    smartfs driver (at least, maybe other things do as well).  Correct a
    bug that was previously masked by having blocksize=eraseblocksize
    which would cause buffer overflows and delicious hardfaults.
    Trivial spelling changes in comments, etc.  From ziggurat29.
  - SmartFS: Fix a 32-byte memory leak.  From Ken Pettit.
  - SMART MTD layer: Fixes freesector logic error when sectorsPerBlk=256,
    adds DEBUGASSERT for invalid geometry and additional memory debug
    logic.  Also fixes the dangling pointer on error bug.  From Ken

* Common Drivers:

  - USB CDC/ACM Device Class: cdcacm_unbind leaks write request objects.
    This arises due to freeing the bulk IN endpoint before the loop
    that frees the requests via cdcasm_freereq.  That function checks
    the parameters and skips the freeing if either is NULL.  Freeing
    the bulk IN enpoint will cause the first param to be NULL, thereby
    bypassing the free operation.  To fix, I moved the release of the
    bulk IN endpoint until after to loop (much as was the case for the
    OUT and read requests, which did not exhibit the problem).  From
  - Pipes and FIFOs: Add missing configuration for pipe ring buffer
    size.  From Frank Benkert.
  - UART 16550: Handle when CONFIG_SERIAL_UART_ARCH_IOCTL is not
    enabled. From Heath Petersen.
  - Common Serial Upper Half:  Fix a race condition noted by Stefan
    Kolb.  Between the test if the TX buffer is full and entering a
    critical section, bytes may be removed from the TX buffer making
    the wait unnecessary.  The unnecessary wait is an inefficiency,
    but not really a problem.  But with USB CDC/ACM it can be a problem
    because the entire TX buffer may be emptied when we lose the race.
    If that happens that uart_putxmitchar() can hang waiting for data
    to be removed from an empty TX buffer.
  - USB MSC Device Class: Add locks when removing request from queue.
    From Wolfgang Reissnegger.
  - USB MSC Device Class: Fix reversed logic on waiting for SCSI thread
    start.  The scsi thread was waiting for the wrong condition.
    However, this was masked by the fact that the code creating the
    scsi thread was also holding usbmsc_scsi_lock(priv) while
    initializing data, hence this lock synchronized the scsi thread
    start with init completion.  From Wolfgang Reissnegger.

* Graphics and Graphic Drivers:

  - Correct conditional compilation in ST7565 LCD driver.  From Pierre-
    noel Bouteville

* Networking:

  - In both IPv6 and IPv4 incoming logic:  (1) Should check if the
    packet size is large enough before trying to access the packet
    length in the IP header.  (2) In the comparison between the IP
    length and the full packet length, need to subtract the size of
    he link layer header before making the comparison or we will get
    false positives (i.e., the packet is really too small)
  - TCP Networking: While working with version 7.10 I discovered a
    problem in TCP stack that could be observed on high network load.
    Generally speaking, the problem is that RST flag is set in
    unnecessary case, in which between loss of some TCP packet and its
    proper retransmission, another packets had been successfully sent.
    The scenario is as follows:  NuttX did not receive ACK for some sent
    packet, so it has been probably lost somewhere. But before its
    retransmission starts, NuttX is correctly issuing next TCP packets,
    with sequence numbers increasing properly. When the retransmission
    of previously lost packet finally succeeds, tcp_input receives the
    accumulated ACK value, which acknowledges also the packets sent in
    the meantime (i.e. between unsuccessful sending of lost packet and
    its proper retransmission). However, variable unackseq is still set
    to conn->isn + conn->sent, which is truth only if no further
    packets transmission occurred in the meantime.  Because of incorrect
    (in such specific case) unackseq value, few lines further condition
    if (ackseq <= unackseq)is not met, and, as a result, we are going to
    reset label.  From Jakub Łągwa.

* ARMv7-M:

  - ARM stack check: Fix double fault on IDLE task with stack size = 0.
    From David Sidrane.

* Atmel SAMV7 Drivers:

  - CAN: CAN Message Filtering fixed: (1) stdfilters didn't work because
    the filter was never enabled (wrong number of bits to shift), and
    (2) Filters were never used because the configuration register
    cannot be written without using the initialization mode. Both bugs
    are fixed by this change. Filtering has been tested with both
    standard and extended identifiers and is now working properly. From
    Michael Spahlinger.

* Atmel SAMA5:

* Atmel SAM3/4 Drivers:

  - Fix some errors in AFEC header file.  From OrbitalFox.
  - Timer:  Fix ops check in TCIOC_STOP.  From Wolfgang Reissnegge.
  - I2C: Fix reversed logic in twi_startmessage().  From Wolfgang
  - SAM3/4 UDP: Fix handling of endpoint RX FIFO banks.  This fixes
    a race condition where the HW fills a FIFO bank while the SW is
    busy, resulting in out of sequence USB packets.

* Atmel SAMV7 Drivers:

  - USBHS Device:  This change solves a problem which causes data loss
    while sending data via USB. This problem is caused by an incorrect
    handling of the endpoint state in the USB driver sam_usbdevhs.  This
    leads under some circumstances to situations in which an DMA
    transfer is setup while a previous DMA transfer is currently active.
    Amongst other things I introduced the new endpoint state
    USBHS_EPSTATE_SENDING_DMA for the fix.  To reproduce the problem, I
    used a program which send as many data as possible via a CDC/ACM
    device and verified the received data on the PC.  From Stefan Kolb.

* NXP Freescale Kinetis Drivers:

  - Timers: Support up to 8 channels per timer.  From kfazz.

* NXP Freescale Kinetis Boards:

  - Teensy 3.x clock fixes:  The High Gain bit in MCG_C1 was preventing
    teensy from booting except after a programming session. The second
    change doesn't appear to change any functionality, but complies with
    restrictions in the k20 family reference manual on FEI -> FBE clock
    transiions.  From kfazz.

* NXP Freescale LPC17xx Drivers:

  - LPC17 Ethernet:  Needs to correctly ignore PHYID2 revision number
    when comparing PHY IDs.

* NXP Freescale LPC43xx Drivers:

  - Fix errors in GPIO interrupt logic.  From v01d (phreakuencies)
  - Ethernet:  Correct auto-negotiation mode in the LPC43xx Ethernet.
    From Alexander Vasiljev
  - Writing zero to NVIC_IRQ_ENABLE has no effect.  Disable interrupts
    with  NVIC_IRQ_CLEAR. From Paul Alexander Patience.
  - SPIFI: If CONFIG_SPIFI_SECTOR512 undefined, lpc43_bwrite doesn't do
    actual write (probably copy/paste errors). Still not sure about
    current state of lpc43_spifi implementation, but for me NXFFS works
    with this change.  From Vytautas Lukenskas.

* Qemu-i486:

  - Fix qemu-i486/ostest/Make.defs test for M32.  From Heath Petersen.

* SiLabs EFM32 Drivers:

  - Fix EFM32 FLASH conditional compilation.  From Pierre-noel
  - Writing zero to NVIC_IRQ_ENABLE has no effect.  Disable interrupts
    with  NVIC_IRQ_CLEAR. From Paul Alexander Patience.

* STMicro STM32:

  - STM32 F1-F4:  In PWM driver, just update duty if frequency is not
    changed and PSM started.  This removeis glitch or blinking when
    only duty is frequently changed.  From Pierre-noel Bouteville.

* STMicro STM32 Drivers:

  - STM32 F7: Fixed STM32F7 DMA stm32_dmacapable.  DMA working on SDMMC.
    From David Sidrane.
  - STM32 F1-F4 Timer Driver: Change calculation of per- timer pre-scaler
    value.  Add support for all timers
  - STM32 F1-F4: Correct conditional compilation in STM32 timer capture
    logic.  From Pierre-noel Bouteville
  - STM32 F1-F4: Fix STM32 DMA code and configuration for STM32F37X chips.
    From Marten Svanfeldt.
  - STM32 F1-F4: Fix compilation errors in debug mode of stm32_pwm.c.
    From Konstantin Berezenko.
  - STM32 F1-F4: Correct the CAN2 RX IRQ number for stm32f10xx chips.
    From Konstantin Berezenko.
  - STM32 F1-F4: Move backup domain reset to to earlier in the
    initialization sequence (stm32_rcc.c() in order to avoid disabling
    LSE during RTC initialiation.  From Alan Carvalho de Assis.
  - STM32 F1-F4: When configuring a GPIO via stm32_configgpio() the
    function will first set the mode to output and then set the initial
    state of the gpio later on.  If you have an application with an
    externaly pulled-up pin, this would lead to a glitch on the line
    that may be dangerous in some applications (e.G. Reset Line for
    other chips, etc).  This changes sets the output state before
    configuring the pin as an output.  From Pascal Speck .
  - STM32 F7: Apply Pascal Speck's GPIO STM32 change to STM32 L4.
  - STM32 L4: Apply Pascal Speck's GPIO STM32 change to STM32 L4.
    From Sebastien Lorquet.
  - STM32 F7:  BUGFIX: PLLs IS2 and SAI P Calculation. From David
  - STM32 L4:  STM32 CAN fixes need to be backported to STM32L4 as well.
  - STM32 F1-F4 and L4: Writing zero to NVIC_IRQ_ENABLE has no effect.
    Disable interrupts with  NVIC_IRQ_CLEAR. From Paul Alexander
  - STM32 F7: STMF7xxx RTC: (1) Remove proxy #defines, (2) Ensure the
    LSE(ON) etal are set and remembered in a) A cold start (RTC_MAGIC
    invalid) of the RTC, and b) A warm start (RTC_MAGIC valid) of the
    RTC but a clock change.  The change was needed because in bench
    testing a merge of the latest's STM32  53ec3ca (and friends) it
    became apparent that the sequence of operation is wrong in the
    reset of the Backup Domain in the RCC code.  PWR is required before
    the Backup Domain can be futzed with. !!!This Code should be tested
    on STM32 and if needed rippled to the STM32 families.  From David
  - STM32 F1-F4: STM32 BBSRAM fixed (and formatted) flags.  From David
  - STM32 F7: STM32F7 BBSRAM fixed (and formatted) flags. From David
  - STM32 L4: Fix incorrect clock setup for LPTIM1.  From ziggurat29.
  - STM32 F4/L4 RTC ALARM: were enabling interrupts too early in the
    power-up sequence,  BEFORE the interrupt system was being

* STMicro STM32 Boards:

  - STM32 board.h: Fix STM32 timer input clock definitions.  From David

* TI Tiva Drivers:

  - Bug Fix in tiva_serial.c - UART5, UART6 and UART7 were not being
    configured as TTYS0 for printing over serial console. From Shirshak

* C Library/Header Files:

  - include/signal.h:  Change type of SIG_ERR, SIG_IGN, ... to
    _sa_handler_t.  The type void does not work with the IAR toolchain.
    From Aleksandr Vyhovanec.
  - crc16: fix error. From  Paul Alexander Patience.
  - strtoul() and strtoull():  Fix errno settings required by function
    definition.  Resolved Bitbucket Issue #1. From Sebastien Lorquet.

* Build/Configuration System:

  - Build system: This change fixes a build problem that only occurs
    when reconfiguring from Linux to Windows or vice-versa.  It is a
    problem that was present but not usually experienced until two
    things happened: (1) The pre_config target was added to run before
    the menconfig operation and (2) the context target was added before
    the pre_config target in order to set up the correct symbolic links
    (in the apps/platform directory) needed by the pre_config target.
    But then now if you start with a Linux system and run 'make
    menuconfig' to switch to Linux, the context target will execute
    first and set up POSIX style symbolic links before doing the
    menuconfig.  Then after the menuconfig, the make will fail on
    Windows if you are using a Windows native toolchain because that
    native toolchain cannot follow the Cygwin- style symbolic links.
    The fix here is to also execute the clean_context AFTER executing
    menuconfig.  A lot more happens now:  It used to be that doing
    'make menuconfig' only did the menuconfig operation.  Now it does
    context, pre_config, menuconfig, clean_context.  Not nearly as
    snappy as it used to be.
  - Need to build the drivers/ directory even it file descriptors are
    not supported.  There are things in the drivers/ directory that are
    still needed (like SYSLOG logic).
  - Remove all inclusion of header files from the apps/include
    directory from NuttX core logic.  There should be no dependency on
    logic within NuttX on logic within apps/.  This caused a lot of
    reshuffling of logic:  binfmt pcode support, usbmonitor is now a
    kernel thread, TZ/Olson database moved to libc/zoneinfo.

* Application Build/Configuration System:

  - Make sure that APPNAME is defined in all Makefiles that generate
    applications.  From Sebastien Lorquet.

* apps/builtins:

  - apps/builtins: exec_builtin was not using the provided open flags.
    As a result >> redirection was not working; it was treated the same
    as >.

* apps/nshlib:

  - apps/nshilib: PS Command: When Priority Inheritance is enabled, the
    format of /proc/<PID>/status changes to show both the current
    priority and the thread’s base priority.  This messes up the format
    of cmd_ps. From David Alessio.

* apps/netutils:

  - apps/netutils, uIP webserver:  Fix a data declaration in a header

* apps/canutils:

  - apps/canutils/libuavcan: Fix for recent change to STM32 timer
    frequency definiitions.

* apps/examples:

  - apps/examples/alarm: ioctl call was clobbering file descriptor.
  - apps/examples/can: Some variables were not declared in all required
    cases. From Sebastien Lorquet.
  - apps/examples/media: media example was intended to take either a
    command line argument, or a compiled-in default value from config.
    However, the default was ignored, leading to confusing error
    messages. From ziggurat29.