ReleaseNotes

    * Automated Configuration. Automated configuration based on the
      kconfig-frontends tool is being incorporated into the build
      system.  The configuration is still not complete enough for
      general use in this release.

    * STM32 Drivers. Added files that will (eventually) hold an STM32
      OTG FS host driver.  This is still a work in progress.

Bugfixes (see the change log for details) :

    * PIC32: GPIO output configuration (critical bug)
    * STM32: Typos in pin mapping files.
    * LM3S:  Fixed an optimization related but that caused slow start-up
      times if optimization was disabled.
    * Library:  Fixed signed extension but in all limit.h files
      (reported by Lorenz Meier).  inet_ntoa compilation failure
      on Z80.

As well as other, less critical bugs (see the ChangeLog for details)

NuttX-6.21
----------

The 88th release of NuttX, Version 6.21, was made on August 25, 2012,
and is available for download from the SourceForge website.  Note
that release consists of two tarballs:  nuttx-6.21.tar.gz and
apps-6.21.tar.gz.  Both may be needed (see the top-level nuttx/README.txt
file for build information).

This release corresponds with SVN release number: r5052

Additional new features and extended functionality:

    * Core: Add support for multiple registered atexit() functions.  Syslog
      extended:  Now any character driver may be used for the debug logging
      device.  Mountpoint traversal logic.
    * Drivers: Added support for the TI PGA112-7 amplifier/multiplexor.
    * LPC43xx:  Added clock ramp-up logic to run at 204 MHz
    * LPC43xx Drivers:  SPIFI block driver, RS-485 support, Minimal termios
      support.  Framework for USB0 device controller driver.
    * LPC17xx Drivers:  Minimal termios support
    * STM32: Support for STM32 F1 "Value Line" (contributed by Mike Smith).
      Add support for STM32 F107 "Connectivity Line" (contributed by Max
      Holtzberg).
      Clock restart logic needed for recovery from low power modes.
    * STM32 Drivers:  RTC alarm support.  Usable for wakeup from sleep mode,
      Minimal serial termios support.  USB OTG FS host driver (alpha).
    * STM32 Boards: Add power management hooks for the STM32F4Discovery,
      Add support for the Olimex STM32-P107 (contributed by Max Holtzberg).
    * PIC32:  Add support for the Pinguino MIPS toolchain.
    * PIC32 Drivers:  GPIO driver now supports F1 analog regiaters (ANSEL).
    * PIC32 Boards: Add support for the PGA117 on the Mirtoo module.
    * Calypso:  Add support for the SSD1783 LCD on the Compal E99.
    * Library:  cfsetispeed(), cfsetospeed(), tcflush(), memchr(), and
      memccpy().
    * Applications:  Port of freemodbus-v1.5.0. Add support for testing
      devices with multiple ADC, PWM, and QE devices.
      NSH: NSH 'mount' command (with no arguments) will now show mounted
      volumes.  Add new NSH 'df' command.  Extended 'help' support. NSH
      now catches the return value from spawned applications (provided
      by Mike Smith).
    * Build System: mkconfig will not define CONFIG_DRAM_END.  A lot of
      progress has been made on the automated NuttX configuration logic
      (Thanks go to Richard Cochran).
    * Documentation: Document ways to customize the behavior of NSH.

Bugfixes (see the change log for details) :

    * Serial drivers (all): Fix ioctl return value. Common "upper half"
      serial driver will now return with EINTR if a serial wait is
      interrupted by a signal.
    * FAT: Fix statfs() file name length.
    * LPC43xx: Clock configuration.
    * STM32: Pinmap fixes, SPI driver re-initialization
    * STM32 Boards: Correct and lower SDIO frequency for F2 and f4 boards.
    * AVR: C++ build issues.
    * PM: Fix a place where interrupts were not be re-enabled.
    * Applications: NSH application start-up race conditions.
    * Library: Fieldwidth and justification for %s format.  Fixed several
      issues with presenting floating point numbers.  NULL definition
      for C++

As well as other, less critical bugs (see the ChangeLog for details)

NuttX-6.22
----------

The 89th release of NuttX, Version 6.22, was made on September 29, 2012,
and is available for download from the SourceForge website.  Note
that release consists of two tarballs:  nuttx-6.22.tar.gz and
apps-6.22.tar.gz.  Both may be needed (see the top-level nuttx/README.txt
file for build information).

This release corresponds with SVN release number: r5206

Note that all SVN information has been stripped from the tarballs.  If you
need the SVN configuration, you should check out directly from SVN.  Revision
r5206 should equivalent to release 6.22 of NuttX 6.22:

    svn checkout -r5206 svn://svn.code.sf.net/p/nuttx/code/trunk nuttx-code

Or

    svn checkout -r5206 http://svn.code.sf.net/p/nuttx/code/trunk nuttx-code

Additional new features and extended functionality:

    * RTOS: Application entry point is no longer user_start, but can be
      configured using CONFIG_USER_ENTRYPOINT.  NuttX now supports two work
      queues:  A lower priority work queue (for extended processing) and a
      higher priority work queue (for quick, high priority operations).

    * Memory Management: Added a new granule-based allocated that can be
      used to manage, aligned and quantized DMA memory.

    * File System: Add hooks to allocate I/O memory with and external
      allocated (need if required by DMA).

    * Networking: ENC28J60 driver is (finally) verified.

    * Drivers: Add hooks USB device drivers to allocate I/O memory with and
      external allocated (need if required by DMA).  Driver for the Windbond
      SPI FLASH family (W25x16, W25x32, W25x64, and others).  ADS7843E driver
      extended for TSC2046 and XPT2046 and verified.

    * ARMv7-M: Added logic to reset the MCU using the NVIC.

    * STM32: Add support for STM32F103VET6.

    * STM32 Drivers: Add logic to re-initialize UARTs a second time to
      enable DMA (Mike Smith).  I2C driver error recovery (Mike Smith).

    * STM32 boards: Support for USB host added add to several configurations
      (or at least explained in README files).  Support for the Shenzhou
      STM32F107 board (see www.armjishu.com).  Support for M3 Wildfire
      STM32F103 board (v2 and v3).

    * Build System:  Kconfig string de-quoting logic.  Remove comments from
      defconfig files (Kate).  Add tool to create NuttX-style symbol tables.
      Numerous changes to configuration logic as needed for the new mconf-based
      configuration (much of this from Richard Cochran).  Refactor common
      Make.defs logic into tools/Config.mk (Richard Cochran).

    * Library: Configurable terse output from strerror(). Added perror() (Kate).
      Add %n format to sscanf() (Kate).

    * Applications: Numerous changes and extensions to the old uIP web server
      (from Kate and Max Holtzberg, see the ChangeLog for specific extensions).
      UDP network discovery utility (Max Holtzberg).  Embeddable Lightweight
      XML-RPC Server (http://www.drdobbs.com/web-development/an-embeddable-lightweight-xml-rpc-server/184405364, Max Holtzberg).

Bugfixes (see the change log for details).  Some of these are very important
(marked *critical*):

    * RTOS: Fixes to priority inheritance logic (*critical*).  waitpid()
      critical section.  Assertion in work_cancel() (Mike Smith).  mmap() (Kate).

    * FAT File System: Improper Boolean expression caused un-necessary writes
      and performance issues (*critical*, Ronen Vainish).

    * Networking: Remove an un-necessary delay from recvfrom().  This greatly
      improves network performance (*critical*, Max Holtzberg).

    * Graphics: NX parameter checking errors.

    * Drivers: Fix double release of memory in SDIO-based, MMC/SD driver
      (Ronen Vainish).

    * LPC17xx:  Ethernet driver fixes needed for certain PHYs (Kate).

    * AVR: Fix build error (Richard Cochran).

    * STM32: USB OTG FS host driver NAKing an retries.  Power management
      compilation errors (Diego Sanchez).  Missing SPI3 remap logic.

    * STM32 Drivers: Fix for Ethernet errata for STM32F107 (*critical*).
      Ethernet buffer alignment check.  Add "kludge" to Ethernet driver to
      handle DM9161 PHY which (at least on the Shenzhou board), sometimes
      does not come up correctly.

    * Applications: THTTPD (Kate).  NSH ping when IP address is on a different
      network (Darcy Gong).

    * Library: fread(), fflush(), fdopen(): Fix error handling logic (Ronen
      Vainish). Fix some field-width handling issues in sscanf()

As well as other, less critical bugs (see the ChangeLog for details)

NuttX-6.23
----------

The 90th release of NuttX, Version 6.23, was made on November 5, 2012,
and is available for download from the SourceForge website.  Note
that release consists of two tarballs:  nuttx-6.23.tar.gz and
apps-6.23.tar.gz.  Both may be needed (see the top-level nuttx/README.txt
file for build information).

This release corresponds with SVN release number: r5313

Note that all SVN information has been stripped from the tarballs.  If you
need the SVN configuration, you should check out directly from SVN.  Revision
r5313 should equivalent to release 6.23 of NuttX 6.23:

    svn checkout -r5313 svn://svn.code.sf.net/p/nuttx/code/trunk nuttx-code

Or

    svn checkout -r5313 http://svn.code.sf.net/p/nuttx/code/trunk nuttx-code

Additional new features and extended functionality:

    * RTOS:  If both atexit() and on_exit() are enabled, use on_exit() to
      implement atexit().  Updates for RGMP 4.0.

    * Binfmt:  Add support for loading and executing ELF binary modules from
      a file system.

    * Drivers:  Maxim MAX11802 touchscreen controller (Petteri Aimonen)

    * STM32 Driver:  Implementation of /dev/random using the STM32 Random Number
      Generator (RNG).

    * STM32 Boards:  ADC support for the Shenzhou IV board.  Relay support for
      the Shenzhou IV board.

    * C Library:  Support is now included for the add-on uClibc++ C++
      standard library support.  This includes support for iostreams, strings,
      STL, RTTI, exceptions -- the complete C++ environment.  (uClibc++ is
      provided as a separate add-on package due to licensing issues).

      Optimized generic and ARM-specific memcpy() function.  Optimized
      memset() function.

      Add support for ferror(), feof(), and clearerror().   Add support for
      __cxa_atexit().

      Math Library:  Port of the math library from Rhombus OS by Nick Johnson
      (Darcy Gong).

    * Applications: New NSH commands:  ifup, ifdown, urlencode, urldecode,
      base64enc, bas64dec, md5 (Darcy Gong).  Add support for NSH telnet login
      (Darcy Gong).  Enancements to NSH ping command to support pinging hosts
      with very long round-trip times.  Extensions to the ifconfig command
      Darcy Gong),

      Many extensions to the webclient/wget and DNS resolver logic from Darcy
      Gong.  JSON, Base64, URL encoding, and MD5 libraries contributed by Darcy
      Gong.

      New examples: ELF loader, JSON, wgetjson, cxxtest, relays.

Bugfixes (see the change log for details).  Some of these are very important
(marked *critical*):

    * Drivers: W25 SPI FLASH

    * STM32 Drivers: ADC reset

    * Graphics: Missing implementation of the blocked method (*critical*,
      Petteri Aimonen).

    * C Library: Floating point numbers in printf and related formatting functions
     (Mike Smith), cf[get|set]speed() (Mike Smith)

As well as other, less critical bugs (see the ChangeLog for details)

NuttX-6.24
----------

The 91st release of NuttX, Version 6.24, was made on December 20, 2012,
and is available for download from the SourceForge website.  Note
that release consists of two tarballs:  nuttx-6.24.tar.gz and
apps-6.24.tar.gz.  Both may be needed (see the top-level nuttx/README.txt
file for build information).

This release corresponds with SVN release number: r5447

Note that all SVN information has been stripped from the tarballs.  If you
need the SVN configuration information, you should check out directly from
SVN.  Revision r5447 should equivalent to release 6.24 of NuttX 6.24:

    svn checkout -r5447 svn://svn.code.sf.net/p/nuttx/code/trunk nuttx-code

Or (HTTP):

    svn checkout -r5447 http://svn.code.sf.net/p/nuttx/code/trunk nuttx-code

Additional new features and extended functionality:

  * RTOS:

    - Implemented the POSIX pause() function (still has some compiance
      issues).
    - Tasking logic is extended to support the notion of address
      environments.  An address environment is the key notion underlying
      "process" vs. tasks.  If tasks are created with address environments
      (by binfmt), the OS will propogate that environment to child threads
      and will destroy the address environment when the "process" exists.
    - If support for the PATH variable is enabled, the OS start up logic
      will create an initial environment containing the default PATH
      setting (CONFIG_PATH_INITIAL).  This initial PATH will then be
      inherited by all tasks.

  * Binfmt

    - The NuttX binary loaders have been updated to support the PATH
      environment variable.  Now, if the PATH is properly defined, programs
      can be executed from mass storage using only the file name.  This
      feature is added to support more standard behavior (eventually, NSH
      will support execution of programs in file systems by just entering
      the file name, perhaps in 6.25?).
    - The NXFLAT and ELF binary loaders have been extended to create
      address environments for any new tasks executed from the file system.
      This feature requires that the architecture support a memory management
      unit (MMU) and the address environment interfaces declared in
      include/nuttx/arch.h (currently, this is only supported by the z180).

    * Drivers: LCD driver for the Univision UG-2864AMBAG01 OLED

    * STM32: Support for STM32F100 high density chips contributed by Freddie
      Chopin.

    * STM32 Drivers:  Added optional RS-485 direction bit control (from
      Freddie Chopin).

    * STM32 Boards:

      - Support for generic STM32F100RC board contributed by Freddie Chopin.
      - stm32f4discovery/nxlines: STM32F4Discovery support for the
        UG-2864AMBAG01 OLED.
      - stm32f4discovery/winbuild:  A version of the NuttX OS test
        configured to build natively on Windows.
      - stm32f4discovery/elf: Now uses the PATH variable to find ELF
        executables.
      - configs/cloudctrl: Added for Darcy Gong's CloudController board

    * PIC32 Boards: Update the Mirtool configuration for Release 2 of the
      Mirtoo module.

    * Calypso: Add Calypso keypad driver.  From Denis Cariki.

    * ZiLOG:

      - Add support for the z180 chip family and, specifically, for
        the P112 retro hardware (see http://p112.feedle.net/).
      - All ZiLOG configurations updated to use the current ZDS-II
        and/or SDCC toolchains.

    * Graphics:

      - Add a semaphore handshake so that operations on buffers from
        the NXMU client will be blocked until the NX server operates on the
        buffer data (from Petteri Aimonen).
      - nxtk_subwindowmove() and nxtk_getwindow(): Improvements to clipping
        logic from Petteri Aimonen.

    * C Library: lib/ sub-directory renamed libc/ (there is a new lib/ sub-
      directory that is used to hold all archives).

    * C++: Exception stubs from Petteri Aimonen.

    * Applications:

      - Add NSH hexdump command to dump the contents of a file (or character
        device) to the console (contributed by Petteri Aimonen).
      - Extend the NSH ifconfig command plus various DHCPC improvements
        (from Darcy Gong).

    * apps/examples:

      - ostest: Replace large tables with algorithmic prime number
        generation.  This allows the roundrobin test to run on platforms
        with minimal SRAM (Freddie Chopin).
      - keypadtest:  A new keypad test example contributed by Denis Carikli.
      - elf and nxflat:  If CONFIG_BINFMT_EXEPATH is defined, these examples
        will now use a relative path to the program and expect the binfmt/
        logic to find the absolute path to the program using the PATH
        variable.

    * Build system:

      - New top-level Makefiles: Makefile.unix and Makefile.win (along with
        numerous changes to other make-related files).  This adds basic
        support for building NuttX natively under Windows from a CMD.exe
        window (rather than in a POSIX-like environment). This build: (1)
        Uses all Windows style paths, (2) Uses primarily Windows batch
        commands from cmd.exe, with (3) a few extensions from GNUWin32.

        This capability should still be considered a work in progress
        because: (1) it has not been verfied on all targets and tools,
        and (2) still lacks some of the creature-comforts of the more
        mature environments (like a function configure.sh script and
        'make menuconfig' support).

      - Example Windows native builds for STM32F4Discovery, eZ80, z16f, z8,
        Z80, and Z180.
      - Several configurations have been converted to work the kconfig-
        frontends mconf configuration tool: stm32f4discovery/nxlines, and
        all eZ80, z16f, z8, Z80, and Z180 configurations.
      - Architectures now include a common Toolchain.defs file that can be
        used to manage toolchains in a more configurable way (most of this
        contributed by Mike Smith).

    * Build tools:

      - Renamed tools/winlink.sh to tools/copydir.sh.
      - Several new tools/scripts to support the Windows native build:
        tools/mkdeps.bat, tools/mkdeps.c, tools/link.bat, unlink.bat, and
        copydir.bat.
      - tools/incdir.sh and incdir.bat now support an -s option to generate
        system header file paths.
      - tools/b16.c: Fixed precision math conversion utility.

Bugfixes (see the change log for details).  Some of these are very important
(marked *critical*):

    * RTOS: Fix some backward conditional compilation in the work queue
      logic (Freddie Chopin).

    * File System: Uninitialized variable caused assertions (from Lorenz
      Meier).

    * Drivers: Partial fix for STM32 OTGFS device drivers and fix for short,
      unaligned writes in the flash translation layer (drivers/mtd/ftl.c),
      both from Petteri Aimonen.

    * STM32 Drivers:

      - Qencoder driver and TIM3 driver fixes from Ryan Sundberg.
      - Fix timeout delay calculation in the STM32 OTG FS host driver.

    * LPC17xx Drivers:  Resources not being properly released when I2C
      driver is un-initialized.

    * Graphics:

      - Fix logic when the mouse drags outside of the window; fix
        another "blocked message" handling case (both from Petteri Aimonen).
      - nxtk_filltrapwindow():  Correct an offset problem (also from Peterri
        Aimonen).
      - nxglib_splitline():  Correct the "fat flat line" bug.

    * C Library:

      - nrand() changes to prevent coefficients from becoming zero which
        would "lock up" the random number generate.
      - Add rounding functions to the math library (contributed by Petteri
        Aimonen).

    * Build system:  Changes to MIN definitions in all limit.h header files
      to avoid integer overflows.  For example from (-128) to (-127 - 1)
      (from Petteri Aimonen).

    * Applications: Modbus fixes from Freddie Chopin.

As well as other, less critical bugs (see the ChangeLog for details)

NuttX-6.25
----------

The 92nd release of NuttX, Version 6.25, was made on February 1, 2013,
and is available for download from the SourceForge website.  Note
that release consists of two tarballs:  nuttx-6.25.tar.gz and
apps-6.25.tar.gz.  Both may be needed (see the top-level nuttx/README.txt
file for build information).

This release corresponds with SVN release number: r5595

Note that all SVN information has been stripped from the tarballs.  If you
need the SVN configuration information, you should check out directly from
SVN.  Revision r5595 should equivalent to release 6.25 of NuttX:

    svn checkout -r5595 svn://svn.code.sf.net/p/nuttx/code/trunk nuttx-code

Or (HTTP):

    svn checkout -r5595 http://svn.code.sf.net/p/nuttx/code/trunk nuttx-code

Additional new features and extended functionality:

    * OS Initialization

      - Removed support for CONFIG_BUILTIN_APP_START.  This is not really a
        useful feature and creates a violation of the OS layered
        architecture.

    * Task Creation:

      - Implement a simple vfork().  In NuttX-6.25, this interface is
        available only for ARM7/9, ARMv7-M (Cortext-M3/4), and MIPS32
        (PIC32MX) platforms.
      - exec() now sets the priority of the new task to the same priority as
        the parent task (instead of the arbirtrary value of 50).
      - New, partially complient implementations of execv() and execl().
        These are only partially compliant because they do not overlay any
        existing "process space" but rather create the new task and exit().
      - Add a complete implementation of posix_spawn().  This standard
        interface is a better match for an MMU-less architecture than are
        vfork() plus execv() or execl().
      - Add a task start hook that will be called before the task main
        is started.  This can be used, for example, to schedule C++
        static constructors to run automatically in the context of the
        new task.

    * Task Parentage

      - Repartitioned tasking data structures.  All shared resources are now
        collected together in a "task group".  A task group includes the
        original task plus all of the pthreads created by the task.
      - Added support for remember the parent "task group" when a new task is
        started.
      - Added optional support to record the membership of each thread in
        the "task group".
      - Implement support for retaining child task status in the "task group"
        after the child task exists.  This is behavior required by POSIX.
        But in NuttX is only enabled with CONFIG_SCHED_HAVE_PARENT and
        CONFIG_SCHED_CHILD_STATUS
      - Add internal logic to "reparent" a task.  This is useful,
        for example, where the child task is created through a trampoline
        task that redirects I/O.  Reparenting allows the caller of posix_spawn()
        to be reparented for the eventual child thread.
      - Added support for SIGCHLD.  Sent to all members of the parent task
        group when the file member of the child task group exits.
      - If SIGCHLD and retention of child task exist status are enabled, then
        a more spec-compliant version of waitpid() is enabled.
      - New interfaces waitid() and wait() are also enabled when SIGCHLD
        is enabled.

    * File System

      - dup() and dup2() can new be used with opened files in a mounted file
        system.  This supports re-direction of output in NSH to files.
      - The binfs file system was moved from apps/builtin to fs/binfs.  The
        binfs file system was extended to support execution of "builtin
        applications" using exec(), execv(), execl(), or posix_spawn().
      - Added logic based on SIGCHLD to automatically unload and clean-up
        after running a task that was loaded into memory.

    * Binary Formats

      - Much of the logic for "builtin applications" was moved from
        apps/builtin to nuttx/binfmt/libbuiltin.  Includes some extensions
        contributed by Mike Smith.
      - A binary loader was added for builtin applications to support
        execution of "builtin applications" using exec(), execv(),
        execl(), or posix_spawn().

    * Drivers:

      - Added logic to marshal and serialized "out-of-band" keyboard
        commands (such as cursor controls and key release events) intermixed
        with normal ASCII keypress data.  The encoding is partially integrated
        in the HID keyboard driver and the decoding full integrated into the
        apps/examples hidkbd and keypadtest (the latter contributed by Denis
        Carlikli).
      - Driver for the UG-2864HSWEG01 OLED contributed by Darcy Gong.
      - Add support for removable serial devices (like USB serial).  This
        support is enabled by CONFIG_SERIAL_REMOVABLE.

    * ARMv7-M:

      - Added an option to use the BASEPRI register to disable interrupts
        (instead of the PRIMASK).  This eliminates some innocuous hardfaults
        that interfere with some debug tools.  You need to switch to the
        BASEPRI method only if you have such tool interference.

    * STM32 Drivers

      - Bring STM32 F1 DMA capabilities up to par with the STM32 F2/F4
        (contributed by Mike Smith).
      - Add support for USART single wire mode (Contributed by the PX4
        team).
      - Updates to support for SPI DMA on the STM32 F1/F2/F4.  From
        Petteri Aimonen.

    * STM32 Boards:

      - New configuration to support the UG-2864HSWEG01 OLED on the
        STM32F4Discovery board.
      - Added a posix_spawn() test configuration for the STM32F4Discovery.

    * LM3S/LM4F

       - Files and directories repartitioned to support both LM3S and LM4F
         using the STM32 organization as a model.
       - Partial definitions for the LM4F contributed by Jose Pablo Carballo
         (this is still a work in progress).

    * LM3S Boards

       - Added scripts and documentation to use OpenOCD with the LM3S (from
         Jose Pablo Carballo).

    * LPC176x/LPC178x

       - Files and directories repartitioned to support both LPC175x/LPC176x
         and the LPC177x/LPC178x families using the STM32 organization as a
         model.  The LPC1788 port is a work in progress by Rommel Marcelo.

    * LPC176x/LPC178x Boards:

      - Added a configuration to support the Wave Share Open1788 board.
        This is still a work in progress by Rommel Marcelo.

    * LPC2148 Boards:

      - Add basic support for the The0.net ZP213x/4xPA board (with the LPC2148
        and the UG_2864AMBAG01 OLED).
      - Add an nxlines configuration for the ZP213x/4xPA (with the LPC2148
        and the UG_2864AMBAG01).

    * Simulator:

      - Add an nxlines configuration for the simulator.

    * Networking:

      - Add logic to work around delayed ACKs by splitting packets
        (contributed by Yan T.).
      - Split net_poll() to create the internal interface psock_poll().

    * LCDs:

      - Added support for LCD1602 alphanumeric LCD (HD4468OU controller).

    * Graphics:

      - Added 5x8 monospace font. This tiny font is useful for graph
        labels and for small bitmapped display.  Contributed by Petteri
        Aimonen.

    * Build System:

      - Add an options to better manage toolchain prefixes.
      - Redesigned how the context targer works in the apps/ directory.
        The old design caused lots of problems when changing configurations
        because there is no easy way to get the system to rebuild the
        context.  This change should solve most the problems and eliminate
        questions like "Why don't I see my builtin application in NSH?"

    * Kconfig Files:

      - There are several new configurations that use the kconfig-frontends
        tools and several older configurations that have been converted to
        use these tools.  There is still a long way to go before the conversion
        is complete:

        configs/sim/nxwm
        configs/sim/nsh
        configs/stm3220g-eval/nxwm
        configs/stm32f4discovery/posix_spawn
        configs/olimex-lpc1766stk/nsh
        configs/olimex-lpc1766stk/hidkbd
        configs/olimex-lpc1766stk/nettest
        configs/open1788/ostest
        configs/stm32f4discovery/nsh
        configs/stm32f4discovery/usbnsh
        configs/lm326965-ek (all configurations)
        configs/mcu123-214x/nsh
        configs/ubw32/ostest

    * Tools:

      - tools/kconfig.bat:  Kludge to run kconfig-frontends from a DOS shell.
      - tools/configure.c:  configure.c can be used to build a work-alike
        program as a replacement for configure.sh.  This work-alike
        program would be used in environments that do not support Bash
        scripting (such as the Windows native environment).
      - tools/configure.bat: configure.bat is a small Windows batch
        file that can be used as a replacement for configure.sh in a
        Windows native environment.  configure.bat is actually just a
        thin layer that executes configure.exe if it is available. If
        configure.exe is not available, then configure.bat will attempt
        to build it first.

    * Applications:

      - New and modified examples:

        apps/examples/wlan: Remove non-functional example.
        apps/examples/ostest: Added a test of vfork(). Extend signal
          handler test to catch death-of-child signals (SIGCHLD). Add a
          test for waitpid(), waitid(), and wait().
        apps/exampes/posix_spawn: Added a test of posix_spawn().

      - NSH:

        NSH now supports re-direction of I/O to files (but still not from).
        The block driver source argument to the mount command is now
          optional for file systems that do not require a block driver.
        NSH can now execute a program from a file system using posix_spawn().
        Added support for a login script.  The init.d/rcS script will be
          executed once when NSH starts; the .nshrc script will be executed
          for each session:  Once for serial, once for each USB connection,
          once for each Telnet session.

      - Supports a new daemon that can be used to monitor USB trace outpout.
      - Removed non-functional wlan example.

Bugfixes (see the ChangeLog for details).  Some of these are very important:

    * Tasking:

      - Fixed a *critical* task exit bug.  Here is the failure scenario:
        (1) sched_lock() is called increments the lockcount on the current
        TCB (i.e., the one at the head of the ready to run list), (2)
        sched_mergepending is called which may change the task at the head
        of the ready-to-run list, then (3) sched_unlock() is called which
        decrements the lockcount on the wrong TCB.  The failure case that
        I saw was that pre-emption got disabled in the IDLE thread, locking
        up the whole system.

    * Signals:

      - sigtimedwait() would return a bad signal number if the signal was
        already pending when the function was called.

    * Drivers:

      - Some SD cards will appear busy until switched to SPI mode for
        first time.  Having a pull-up resistor on MISO may avoid this
        problem, but this fix from Petteri Aimonen makes it work also
        without pull-up.

    * STM32 Drivers:

      - STM32 FLASH driver counting error (from Freddie Chopin).
      - STM32 F4 maximum SPI frequency was wrong (corrected by Petteri
        Aimonen).

    * STM32 Boards

      - Due to cloning of untested code, the logic to control on-board
        LEDs did not work on any STM32 boards.
      - Serial devices number /dev/ttyS0-5 is there is a serial console,
        but /dev/ttyS1-6 if there is no serial console.

    * Binary Formats

      - C++ static constructors execute now using a start taskhook
        so that they execute in the context of the child task (instead
        of in the context of the parent task).

    * File Systems:

      - Several FAT-related bugs fixed by Petteri Aimonen.

    * Networking:

      - Fix poll/select issure reported by Qiang: poll_interrupt() must call
        net_lostconnection() when a loss of connection is reported.  Otherwise,
        the system will not remember that the connection has been lost and will
        hang waiting on a unconnected socket later.
      - Similar issues corrected for recvfrom() and send().
      - Telnetd would hang in a loop if recv() ever returned a value <= 0.

    * Libraries:

      - fread() could hang on certain error conditions.
      - Can't handle SYSLOG output to a character device from  the IDLE task
        (because the IDLE task can't block).

    * Build System:

      - Serial was driver was not being built if there is no console
        device.  Obviously, the serial driver may be needed even in
        this case.

    * Additional Bugfixes:

      - sig_timedwait() and clock_time2ticks.c: Timing "rounding" logic
      - ARM9 Compilation issue with low vectors.
      - readline() return value
      - Others as detailed in the ChangeLog: HID keyboard, LPC17xx bit
        definitions, strndup(), PL2303, SYSLOG error handling, AT25,
        apps/examples.

NuttX-6.26
----------

The 93rd release of NuttX, Version 6.26, was made on March 15, 2013,
and is available for download from the SourceForge website.  Note
that release consists of two tarballs:  nuttx-6.26.tar.gz and
apps-6.26.tar.gz.  Both may be needed (see the top-level nuttx/README.txt
file for build information).

This release corresponds with SVN release number: r5745

Note that all SVN information has been stripped from the tarballs.  If you
need the SVN configuration information, you should check out directly from
SVN.  Revision r5745 should equivalent to release 6.26 of NuttX:

    svn checkout -r5745 svn://svn.code.sf.net/p/nuttx/code/trunk nuttx-code

Or (HTTP):

    svn checkout -r5745 http://svn.code.sf.net/p/nuttx/code/trunk nuttx-code

Additional new features and extended functionality:

    * OS Initialization:

      - Add an additional call-out to support board-specific driver
        initialization during the boot-up phase (available with
        CONFIG_BOARD_INITIALIZE=y).

    * Tasking:

      - New interface task_spawn() that is like posix_spawn(), but uses
        entry point addresses like task_create().
      - Additional data restructuring as a continuation of the task group
        changes of NuttX 6.25.  These data structures were moved from the
        TCB structure into the task group:  pthread join data,
        atexit/on_exit callbacks, waitpid data structures, and message
        queues.
      - TCBs for tasks and pthreads are now separate structures.  This
        saves a little memory since tasks do not have to carry the overhead
        for threads and vice versa.

    * Kernel Build:

      - Extensive changes were made to support the kernel build mode.  In
        this mode, NuttX is built as a monolithic kernel.  NuttX is built
        as a separate kernel mode "blob" and the applications are built
        as a separate user mode "blob".  The kernel runs in kernel mode and
        the applications run in user mode (with the MPU restricting user
        mode accesses).  Access to the kernel from the user blob is only
        via system calls (SVCalls).
      - Extensive changes were made to the syscall, SVCall, and trapping
        logic.  Many internal interfaces were renamed.
      - The memory manager was extended to support both kernel- and user-
        mode allocations.  Logic within the kernel needs to use the
        correct kernel- or user-space allocator, depending upon the user
        of the allocated memory.
      - The user-space blob now contains a header built in at the beginning
        of the block that provides the same information that was previously
        provided by a kludgy, auto-generated header file (user_map.h).
      - Basic support implemented for the ARMv7-M family with fragments
        also implemetned for the ARMv6-M and MIPS32 families.
      - Kernel build supported added for the LPC17xx Open1788 and for
        the Atmel SAM3U-EK board.  All testing is being performed on the
        Open1788 board.

    * Signals:

      - Delivery of signals to threads within a task group is now compatible
        with the way that signals are delivered to threads within a process.

    * Drivers:

      - Add a driver for the SST29VF NOR FLASH parts.
      - USB device trace/debug feature extended to decode device-specific
        trace events to make the trace output more readable (from Petteri
        Aimonen).
      - USB MSC device driver can not support names of differing sizes
        in the USB descriptor and the SCSI fields (from Petteri Aimonen).
      - Locking added to MMC/SD SPI drivers so that MMC/SD can co-exist on
        the same bus as other SPI devices.  Frequency is reset each time
        that the MMC/SD SPI has the bus locked. (from Petteri Aimonen).

    * ARMv6-M (Cortex-M0):

       - Added support for the ARM Cortex-M0 family.

    * nuvoTon NUC120:

       - Added support for the nuvoTon NUC120 MCU (Cortex-M0).

    * nuvoTon NUC120 Boards:

       - Added basic support for the nuvoTon NuTiny-SDK-NUC120 board (Cortex-M0).

    * LPC17xx:

      - Added support for the LPC177x and LPC178x families.  Most of this is
        the work of Rommel Marcelo.

    * LPC17xx Boards:

      - Added support for Zilogic System's ARM development Kit, ZKIT-ARM-1769.
        From Rashid.
      - The port for the WaveShare Open1788 board is now functional.  Basic
        OS test and NuttShell (NSH) configurations are functional. More
        driver development and testing is needed (from Rommel Marcelo).

    * LPC17xx Drivers:

      - Added an SD card MSI driver for the LPC178x.  The driver is marginally
        functional but requires DMA capability to be reliable.

    * STM32

      - Support extended to handle the STM32 F3 family (Cortex-M4 with F1-like
        peripherals).

    * STM32 Boards

      - Added support the STMicro STM32F3Discovery board (STM32 F3).

    * Stellaris LM3S/LM4F

      - Basic support for the LM4F120 family is in place, but untested (mostly
        from Jose Pablo Carballo).

    * Stellaris LM4F Boards

      - Add support for the LM4F120 LaunchPad (untested).

    * Networking:

      - select() should now allocate a little less memory.

    * Memory Management:

      - Extended to support multiple heaps.  This is used as part of
        the kernel build in order to support separater user- and
        kernel-mode heaps.
      - The stand-alone memory manger test had to be removed.  It
        was too entangled and made extension of the memory manager
        nearly impossible.  This is a loss.

    * Build System:

      - Several configurations converted to use the kconfig-frontends
        configuration tool.  There are still many more that need to
        be converted.

    * C Library:

      - Move the workqueue logic into the C library.  There is now a
        special user-space version of the work queue (which will only
        be used with a NuttX kernel build).
      - Implementation of itoa() contributed by Ryan Sundberg.

    * Applications:

      - The NSH builtin task logic now uses task_spawn() to start builtin
        applications.
      - The OS test now includes a test cased to verify task_restart().

Efforts In Progress.  The following are features that are partially
implemented but present in this release.  Most are expected to be fully
available in NuttX 6.27.

    * LM4F120 LaunchPad port.  Code is in place, but nothing has been tested.

    * WaveShare Open1788 port.  This port as actually complete and
      functional. However, there is still ongoing development and
      testing of drivers.

    * Kernel Build.  Much progress has been made, but there kernel build is
      not yet fully functional due to several user resources that are not yet
      properly disentangled from the kernel blob.

    * Conversion of old configurations to use the kconfig-frontends
      tool is an ongoing effort that will continue for some time.

Bugfixes (see the ChangeLog for details).  Some of these are very important:

    * Tasking:

      - The wrong PID was being signalled with SIGCHILD.  It should be
        the PID of the task that create the task group, not the ID of
        the last thread to leave the task group.
      - Added logic so that some internal resources and states are recovered
        when tasks are deleted or restarted.  Handle cases where there are
        outstanding timed events pending when tasks are deleted or restarted.

    * ARMv7-M:

      - Several fixes to the MPU control logic.

    * Drivers:

      - Removable serial drivers race conditions fixed.
      - MAX11802 timing bug (from Petteri Aimonen).

    * STM32 Drivers:

      - Handle cases were SPI DMA logic fails if sem_wait is awakened
        by a signal.  Need to clear error flags to prevent corruption of
        subsequent transfers.  Also, bit count should not be changed while
        the SPI peripheral is enabled (from Petteri Aimonen).
      - Fixes to the OTG FS device driver from Petteri Aimonen.
      - Fix typos in DMA register header file (from Yan T.)

    * Graphics:

      - Correction to the hyphen in the SANS 17x22 font (from Petteri
        Aimonen).

    * Networking:

      - Corrected errors in the socket poll/select logic.  Additional
        state logic was needed to detect if the socket is still connected
        before starting the poll wait. (bug reported by Qiang Yu).

    * Memory Management: