https://bitbucket.org/nuttx/nuttx/downloads
https://bitbucket.org/nuttx/apps/downloads

* Core OS:

  - Add standard adjtime() interface and basic timekeeping support.
    Normally used with an NTP client to keep system time in
    synchronization.  From Max Neklyudov.
  - Use the oneshot timer with optional entropy to measure CPU load if
    so configured.

* File System and Block and MTD Drivers:

  - Add Fujistu MB85RS256B ramtron support.  From Beat Küng.
  - SPI-based MTD driver for Macronix MX25L3233F or MX25L6433F.  From
    Aleksandr Vyhovanec.

* Graphics/Display Drivers:

  - SH1106 0.96 OLED module support (SSD1306 compatible) + I2C fixes.
    From v01d (phreakuencies).

* Sensor Drivers:

  - Add KXJT9 Accelerometer driver from the Motorola Moto Z MDK.
  - Add MFRC522 RFID ISO14443 and Mifare transceiver driver.  From Alan
    Carvalho de Assis.
  - Add driver for the LIS3MDL 3 axis magnetometer.  From Alexander
    Entinger.
  - Add driver for the MLX90393 3 axis magnetometer. From Alexander
    Entinger.
  - Add driver for the LIS3DSH 3 axis accelerometer. From Alexander
    Entinger.
  - Add driver for the Bosch BMG160 3 axis gyroscope. From Alexander
    Entinger.
  - Add support for the  Sensixs XEN1210 3D-board. This sensor is used
    on NANOSATC-BR2 a Brazillian CUBESAT project.  From Alan Carvalho
    de Assis.
  - Add a new ioctl command (set MAXPOS) for Tiva QEI.  From Young.

* Other Common Device Drivers:

  - I/O Expander: Remove hard-coded PCA9555 fields from ioexpander.h
    definitons.  Add support for an attach() method that may be used
    when any subset of pin interrupts occur.
  - I/O Expander Interface:  Encode and extend I/O expander options to
    include interrupt configuration.
  - PCA9555 Driver:  Replace the signalling logic with a simple callback
    using the new definitons of ioexpander.h.  This repartitioning of
    functionality is necessary because (1) the I/O expander driver is
    the lower-lower part of any driver that uses GPIOs (include the GPIO
    driver itself) and should not be interacting directly with the much
    higher level application layer.  And (2) in order to be compatible
    with the GPIO driver (and any arbitrary upper half driver), the
    PCA9555 should not directly signal, but should call back into the
    upper half.  The upper half driver that interacts directly with the
    application is the appropriate place to be generating signal.
  - Add a skeleton I/O Expander driver (based on the PCA9555 driver).
  - Add PCF8574 I/O Expander driver.
  - GPIO driver:  Add IOCTLs to get the pin type and to unregister a
    signal handler.
  - Add a GPIO lower-half driver that can be used to register a GPIO
    character driver for accessing pins on an I/O expander.
  - Add an SPI helper function that encapsulates and manages a sequence
    of SPI transfers.
  - Add an SPI character driver that will permit access to the SPI bus
    for testing purposes.
  - Add oneshot timer lower half interface definition.
  - Add an upper-half, oneshot timer character driver.
  - Add Audio Tone Generator for NuttX.  From Alan Carvalho de Assis.
  - Add USB host support for composite devices.  This feature is not
    well tested.
  - drivers/ioexpander: Add an (untested) TCA64XX I/O Expander driver
    leveraged from Project Ara.

* Simulation Platform:

  - Add a simulated I/O Expander driver.
  - Add simulator-based test support for apps/examples/gpio.
  - Add a configuration useful for testing Mini Basic.
  - Add a simulated oneshot lowerhalf driver.

* Atmel SAM3/4 Drivers:

  - SAM4CM: Add option to support oneshot timer without free-running
    timer.  Add oneshot lower half driver.

* Atmel SAMA5 Drivers:

  - SAMA5D: Add option to support oneshot timer without free-running
    timer.  Add oneshot lower half driver.

* Atmel SAMV7 Drivers:

  - SAMV71/SAME70: Add option to support oneshot timer without
    free-running timer.  Add oneshot lower half driver.
  - Add support for SAMV7 DACC module.  From Piotr Mienkowski.

* NXP Freescale Kinetis Drivers:

  - Add support for I2C and RTC.  From v01d (phreakuencies).

* NXP Freescale Kinetis Boards:

  - Add teensy 3.x I2C support.  From v01d (phreakuencies).

* STMicro STM32:

  - Add IAR-style STM32F1xx vectors. Tested on STM32F103RB and
    STM32F107RC.  From Aleksandr Vyhovanec.

* STMicro STM32 Drivers:

  - Add timekeeping support for the STM32 tickless mode.  From Max
    Neklyudov.
  - Add a oneshot, lower-half driver for STM32.
  - STM32 L4: Add oneshot lower half driver for STM32 L4.
  - STM32 L4: Add support for quadrature encoders on STM32L4. Sebastien
    Lorquet.

* STMicro STM32 Boards:

  - stm32f103-minimum: Add board support to MFRC522 driver.  From Alan
    Carvalho de Assis.
  - Add oneshot board initialization to stm32f103-minimum.  From Alan
    Carvalho de Assis.
  - stm32f103-minimum: Add board configuration to initialize Audio Tone
    Generator.  From Alan Carvalho de Assis.
  - stm32bufferfly2: Add support for the Kamami stm32butterfly2
    development board with optional ETH phy.  From  Michał Łyszczek.
  - stm32f103-minimum: Add board config support to SPI LCD module
    JLX12864G-086.  From Alan Carvalho de Assis.
  - stm32l476-mdk: Support basic booting and nsh on Motorola MDK. The
    Motorola MDK is based off of an earlier version of NuttX.
    This only provides a basic NSH shell.  From Jim Wylder.
  - STM32 F4 Discovery:  Add support for XEN1210 3D-board.  From Alan
    Carvalho de Assis.
  - stm32f103-minimum:  Add stm32_bringup support and userled example to
    STM32F103 Minimum board.  From Alan Carvalho de Assis.
  - Add support for qencoders on various nucleo boards.  From Sebastien
    Lorquet.
  - olimex-stm32-e407: Add some networking configurations.  From Mateusz
    Szafoni.

* TI Tiva Drivers:

  - Add tiva PWM lower-half driver implementation. From Young.
  - Tiva QEI:  Add QEI lower-half driver for Tiva series chip.  From
    Young.

* C Library/Header Files:

  - Separate XorShift128 PRNG from /dev/urandom and make it generally
    available.
  - Add POSIX type sig_atomic_t.  From Sebastien Lorquet.
  - Add the difftime() function.  The function depends on the toolchain-
    dependent CONFIG_HAVE_DOUBLE so is not available on tiny platforms.
    From Sebastien Lorquet.
  - Add support for remove().  From Sebastien Lorquet.
  - Add system() to stdlib.h.  Actual implementation is in
    apps/system/system.

* Build/Configuration System:

  - Rename arch/sh to arch/renesas.
  - Remove contactless drivers from drivers/wireless to drivers
    contactless.  From Sebastien Lorquet.
  - Move all modem-related IOCTL commands to a common file to assure
    that they will be unique.

* Tools:

  - Add sethost.sh.   This is a script that you can use to quickly
    change the host platform from Linux to Windows/Cygwin. Might save
    you a lot of headaches.

* Applications: apps/nshlib:

  - Add logic to support an NSH-specific system command.
  - Add printf command to NSH, e.g., controlling /dev/userleds from
    command line: nsh> printf \x01 > /dev/userleds. From Alan Carvalho
    de Assis.

* Platforms: apps/system:

  - Port tee command from NetBSD.
  - Add a generic system command.  Current implentation cannot use
    /bin/sh and spawns the custom NSH system command directly.

* Platforms: apps/platform:

  - Add C++ support for STM32L476-MDK.

* Platforms: apps/interpreters:

  - Add a port of Mini Basic, version 1.0, written by Malcom McLean and
    released under the Creative Commons Attribution license.

* Applications: apps/examples:

  - Add a simple test of the GPIO driver.
  - Add RFID_READUID sample application. From Alan Carvalho de Assis.
  - Add Oneshot timer example.
  - Add a simple test of the system command.

* 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-7.19.

* Core OS:

  - Explicitly initialize the group tg_exitsem with sem_init().  The
    existing logic worked because the correct initialization value is
    all zero, but it is better to initialize the semaphore explicitly.
  - The TCB nchildren field should not be incremented when pthreads are
    created.
  - Move fields related to parent/child task relationship out of TCB
    into group structure where they belong.  Child is a group, not a
    thread.
  - mq_send() was not setting the errno value on certain failures to
    allocate a message.
  - Define 'group' even if HAVE_GROUPID is not set.  From Mateusz
    Szafoni.
  - Vector table should have dimension NR_IRQS, not NR_IRQS+1. From
    Sagitta Li.
  - pthreads:  When a pthread is started, there is a small bit
    of logic that will run on the thread of execution of the new
    pthread.  In the case where the new pthread has a lower
    priority than the parent thread, then this could cause both the
    parent thread and the new pthread to be blocked at the priority of
    the lower priority pthread (assuming that CONFIG_PRIORITY_INHERITANCE
    is not selected). This change temporarily boosts the priority of the
    new pthread to at least the priority of the new pthread to at least
    the priority of the parent thread.  When that bit of logic has
    executed on the thread of execution of the new pthread, it will then
    drop to the correct priority (if necessary) before calling into the
    new pthread's entry point.

* File System/Block Drivers/MTD Drivers:

  - FAT performance improvement. In large files, seeking to a
    position from the beginning of the file can be very time consuming.
    ftell does lssek(fd, 0, SET_CURR).  In that case, that is wasted
    time since we are going to seek to the same position.  This fix
    short-circuits fat_seek() in all cases where we attempt to seek to
    current position.  Suggested by Nate Weibley.
  - MTD: Fixed cloned typos in several FLASH drivers.  From Aleksandr
    Vyhovanec.
  - mount: Corrects a bad assertion noted by Pierre-noel Bouteville.
    Also fixes a reference counting problem in an error condition:
    When the mountpoint inode is found but is not an appropriate
    mountpoint, the reference count on the inode was not being
    decremented.

* Common Drivers:

  - Various serial drivers: Fix FIONWRITE and add FIONSPACE.  All
    implementations of FIONWRITE were wrong.  FIONWRITE should return
    the number of bytes waiting in the outgoing send queue, not the free
    space.  Rather, FIONSPACE should return the free space in the send
    queue.
  - Add missing prototype for btn_lower_initialize().
  - Make DAC sample structure packed.  From Marc Rechté.

* Networking:

  - TCP:  tcp_ipvX_bind() not actually using the port selected with
    port==0.  Also removes duplicate call to pkt_input().  Issues noted
    by Pascal Speck.
  - drivers/net: NET_TUN=y => NET_MULTIBUFFER=y.  From Vladimir
    Komendantskiy.
  - slip driver: Fix calculations using MSEC_PER_TICK.  If
    USEC_PER_TICK is less than 1000, then MSEC_PER_TICK will be
    zero.  It will be inaccurate in any case.

* Atmel SAM3/4 Drivers:

  - SAM3/4 GPIO: Enable peripheral clock for GPIO port when GPIO is
    configured as input. The value of a GPIO input is only sampled when
    the peripheral clock for the port controller the GPIO resides in is
    enabled.  Therefore we need to enable the clock even when polling a
    GPIO.  From Wolfgang Reissnegger.
  - All SAM Ethernet Drivers: Add support so that the drivers can be
    built with CONFIG_NET_MULTIBUFFER=y.
  - SAM3/4: Fix GPIO pull-up/down code. Enabling the pull-down resistor
    while the pull-up resistor is still enabled is not possible. In this
    case, the write of PIO_PPDER for the relevant I/O line is discarded.
    Likewise, enabling the pull-up resistor while the pull-down resistor
    is still enabled is not possible. In this case, the write of
    PIO_PUER for the relevant I/O line is discarded.  From Wolfgang
    Reißnegger.

* Atmel SAMV7 Drivers:

  - All SAM Ethernet Drivers: Add support so that the drivers can be
    built with CONFIG_NET_MULTIBUFFER=y.
  - SAM GPIO: Apply Wolfgang's change for SAM3/4 to SAMA5 and SAMV7.

* Atmel SAMA5:

  - Add missing oneshot max_delay method.
  - All SAM Ethernet Drivers: Add support so that the drivers can be
    built with CONFIG_NET_MULTIBUFFER=y.
  - SAM GPIO: Apply Wolfgang's change for SAM3/4 to SAMA5 and SAMV7.

* NXP Freescale LPC43xx Drivers:

  - LPC43xx serial: Fix typos in LPC43 serial driver.  Found by Vytautas
    Lukenskas.
  - LPC43xx Serial: There are some small problems in LPC43xx RS485 mode
    configuration. In particular: (1) UART0,2,3 do not have DTR pins
    (different from UART1), so, Kconfig needs to be adjusted. (2)
    lpc43_uart.c in RS485 mode only configures DIR pin, but doesn't
    enable pin output for UART0,2,3. (3) should be option to reverse DIR
    control pin output polarity. (4) lpc43xx/chip/lpc43_uart.h doesn't
    have USART3 definitions.  NOTE: I didn't modified and didn't tested
    USART1, as it has different hardware.  From Vytautas Lukenskas.
    From Vytautas Lukenskas.

* SiLabs EFM32 Drivers:

  - EFM32 SPI drivers adopted incompatible conventions (See STM32 for
    details of the issue).

* STMicro STM32 Drivers:

  - STM32, STM32 L4, and EFM32 SPI drivers adopted incompatible
    conventions somewhere along the line.  They set the number of bits
    to negative when calling SPI_SETBITS which had the magical side-
    effect of setting LSB first order of bit transmission.  This is not
    only a hokey way to pass control information but is supported by no
    other SPI drivers.  This change three things:  (1) It adds
    HWFEAT_LSBFIRST as a new H/W feature. (2) It changes the
    implementations of SPI_SETBITS in the STM32 and EFM32 drivers so
    that negated bit numbers are simply errors and it adds the
    SPI_HWFEATURES method that can set the LSB bit order, and
    (3) It changes all calls with negative number of bits from all
    drivers: The number of bits is now always positive and
    SPI_HWFEATURES is called with HWFEAT_LSBFIRST to set the bit order.
  - Add missing SPI2 and SPI3 support for STM32F3F3.  Add STM32F37XX DMA
    channel configuration.  For STM32F37XX, SYSCFG_EXTICR_PORTE defined
    twice.  From Alan Carvalho de Assis.
  - STM32: Make stm32_pwr_enablebkp thread safe.  From Max Neklyudov.
  - Fix bad pllmul values for STM32F1XX connectivity line. STM32F1XX
    connectivity line supports only x4, x5, x6, x7, x8, x9 and x6.5
    values. From Michał Łyszczek.
  - STM32F3 SPI:  Fix the number of bit setting for the F3.  That and
    data packing work differently on the STM32F3 than for other STM32
    parts.
  - STM32 and STM32 L4: Enabling SPI DMA loses other bits in CR2.
  - STM32F3 SPI:  Cannot write always 16-bit value to DR register
    because of how the F3 implements data packing.
  - STM32F411 and STM32F446 map i2c2_sda_4 to different alternate
    function numbers.  From Konstantin Berezenko.
  - STM32 DMA Fix: Change stm32 adc dma callback to send channel
    number instead of index.  From Konstantin Berezenko.
  - STM32 OTGFS device: Fix for lost first word from FIFO

    1) Do not overwrite Reserved Bits in GINTSTS (per ref manual)*
    2) Acknowledge all pending int on entry to ISR that are Only rc_w1*
    3) Do not disable RXFVL*
    4) Loop until RXFVL is cleared*
    5) Only clear the NAK on the endpoint on the OTGFS_GRXSTSD_PKTSTS_SETUPDONE to not loose the first WORD of FIFO all the data  (Bug Fix)

    Changed marked *are just driver clean up and ensure ints are not lost. The bug fix is #5

    Test case open putty and observer the Set/Get LineCoding. Without this fix #5 the Get will not match the Set, and in fact the data might be skewed by 4 bytes, that are lost from the FIFO if the OTGFS_DOEPCTL0_CNAK bit is set in the OTGFS_GRXSTSD_PKTSTS_SETUPRECVD as opposed to the OTGFS_GRXSTSD_PKTSTS_SETUPDONE

    Set Line Coding DATA1: 4B | 00 c2 01 00 00 00 08 | c8 1B
    Get Line Coding DATA1: 4B | .. .. .. .. 00 00 08   c8 .. 00 00 07 | 7a 72

    From David Sidrane.
  - STM32 L4 OTGFS device: Apply stm32 fix to stm32l4.  From Sebastien
    Lorquet.
  - STM32 F7: Remove duplicate call to pkt_input from Ethernet driver.
    Issues noted by Pascal Speck.
  - STM32 L4: Add support for USART3-USART5.  For STM32L4 parts, the
    higher number USART ports supported varies.  Add the HAVE_USARTx
    definitions to the configuration to allow enabling the higher
    numbered USART ports. From Jim Wylder.
  - STM32 USB: Set USB address to avoid a failed assertion.  From
    Pierre-noel Bouteville.
  - STM32 L4 and L7 USB: Pierre's assertion-avoidance change should
    also be applied to STM32 F7 and L4.
  - STM32, L4, and F7:  Remove GPIO_ETH_RMII_TX_CLK. TX_CLK is not
    present in RMII. Mateusz Szafoni.
  - STM32 Ethernet: Correct typo in conditional logic.  From Neil
    Hancock.
  - STM32 L4 USB Device: Fixed L4 USB Driver by avoiding SETUPDONE and
    EPOUT_SETUP.  From David Sidrane.
  - STM32 SPI: stm32_modifycr2 should be available on all platforms if
    DMA is enabled.
  - STM32 DMA2D: fix an error in up_dma2dcreatelayer where an invalid
    pointer was returned when a certain underlying function failed.
    From Jens Gräf.

* TI Tiva Drivers:

  - Fix two bugs of tiva pwm lower-half driver implementation. From
    Young.
  - Tiva Ethernet:  Needs support for CONFIG_NET_MULTIBUFFER=y.

* C Library/Header Files:

  - lib_dumpbuffer() now prints a large on-stack buffer first to avoid
    problems when the syslog output is prefixed with time.  From
    Pierre-noel Bouteville.
  - libc/math: This fixes the following libc/math issues: (1) asin[f l]()
    use Newton’s method to converge on a solution. But Newton’s method
    converges very slowly (> 500,000 iterations) for values of x close to
    1.0; and, in the case of asinl(), sometimes fails to converge (loops
    forever). The attached patch uses an trig identity for values of
    x > sqrt(2). The resultant functions converge in no more than 5
    iterations, 6 for asinl().  (2) The NuttX erf[f l]() functions are
    based on Chebyshev fitting to a good guess. The problem there’s a
    bug in the implementation that causes the functions to blow up with
    x near -3.0. This patch fixes that problem. It should be noted that
    this method returns the error function erf(x) with fractional error
    less than 1.2E-07 and that’s fine for the float version erff(), but
    the same method is used for double and long double version which
    will yield only slightly better precision. This patch doesn't
    address the issue of lower precision for erf() and erfl(). (3) a
    faster version of copysignf() for floats is included. From David S.
    Alessio.
  - strtod() was not returning endptr on error conditions.
  - libc/math: floor(), floorf(), and floorl():  Fix logic error.  Was
    not correctly handling negative integral value.
  - isatty() should be prototyped in unstid.h, not termios.h.  From
    Sebastien Lorquet.
  - nxglib: Fix handling of near-horizontal lines of width 1 in
    nxgl_splitline().  Missing handling for degenerate condition caused
    width 1 lines such as (0, 0) - (100, 10) to have gaps in the
    drawing. From Petteri Aimonen.

* Build/Configuration System:

  - Top-Level Makefiles:  Fix a chicken-and-egg problem. In the menuconfig
    target, the context dependency was executed before kconfig-mconf.  That
    was necessary because the link at apps/platform/board needed to be set
    up before creating the apps/Kconfig file.  Otherwise, the platform
    Kconfig files would not be included.  But this introduces the chicken-
    and-egg problem in some configurations. In particular:  (1) An NX
    graphics configuration is used that requires auto-generation of
    source files using cpp, (2) the configuration is set for Linux, but
    (3) we are running under Cygwin with (4) a Windows native toolchain.
    In this case, POSIX-style symbolic links are set up but the Windows
    native toolchain cannot follow them. The reason we are running
    'make menuconfig' is to change from Linux to Cygwin, but the target
    fails.  During the context phase, NX runs CPP to generate source files
    but that fails because the Windows native toolchain cannot follow
    the links.  Checkmate.  This was fixed by changing all of the make
    menuconfig (and related) targets.  They no longer depend on context
    being run.  Instead, they depend only on the dirlinks target.  The
    dirlinks target only sets up the directory links but does not try
    to run all of the context setup; the compiler is never invoked; no
    code is autogenerated and things work.
  - CXXFLAGS: add -fcheck-new whenever -fno-exceptions is used. From
    Beat Küng.

* Tools

  - tools/refresh.sh: Recent complexities added to apps/ means that
    configuration needs the correct Make.defs file in place in order to
    configure properly.
  - tools/kconfig2html.c: Update to handle absolute paths when sourcing
    Kconfig files.
  - tools/mkfsdata.pl was still generating the old-style apps/include
    inclusion paths.

* Application Build/Configuration System:

  - Add DIRLINK and DIRUNLINK tool definitions to apps/Make.defs.

* apps/nshlib:

  - Fix FIFO_SIZE vs PIPE_SIZE.
  - Fix hex representation of IP address in Kconfig.  Noted by Michal
    Lyszczek.
  - nsh_syscmds.c: missing semicolon.  From Mateusz Szafoni.
  - In system command, don't try to flush output streams if stdio
    buffered I/O is not supported.

* apps/canutils:

  - libuavcan: Under certain circumstances, DELIM is not be defined in
    Makefile.
  - Add definition for APPNAME in apps/canutils/canlib.  From Sebastien
    Lorquet.

* apps/gpsutils:

  - Fix an error minmea.  From Aleksandr Vyhovanec.

* apps/examples:

  - apps/examples/oneshot:  If the requested delay is > max_delay, then
    break the delay up into several pieces.