ReleaseNotes

        NSH session would terminate because it thought it was the end of
        file.

NuttX-6.27
^^^^^^^^^^

The 94th release of NuttX, Version 6.27, was made on April 28, 2013,
and is available for download from the SourceForge website.  Note
that release consists of two tarballs:  nuttx-6.27.tar.gz and
apps-6.27.tar.gz.  Both may be needed (see the top-level nuttx/README.txt
file for build information).

Additional new features and extended functionality:

    * OS Initialization:

      - Add missing registration of /dev/zero.  Registration of /dev/null
        should depend upon conditional compilation.  From Ken Pettit.

    * Tasking:

      - Added a new interface to set aside memory on the task's stack.  This
        is used (at least in the kernel build) to hold task arguments.
      - Remove up_assert_code().  One assertion routine is enough.

    * 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).
      - Kernel build configurations for the Open1788 board and for the
        STM32F4Discovery now execute correctly.
      - Changes were made to task and thread start-up routines, signal
        handling, data structures, ARMv7-M SVCalls, stack management
        interfaces,

    * Drivers:

      - Driver for the ST7567 LCD Display Module from Univision Technology
        Inc.  Contributed by Manikandan.S
      - SPI initialize functions renamed so that multiple SPI blocks can
        be initialized.
      - Extended to support the RAMTRON FM25V01 device. Contributed by
        Lorenz Meier
      - Serial drivers: TIOCSERGSTRUCT ioctls now conditioned on
        CONFIG_SERIAL_TIOCSERGSTRUCT

    * ARMv7-M (Cortex-M3/4):

      - Added support for modifiable interrupt vectors in RAM

    * nuvoTon NUC1xx:
 
      - Added kernel build support

    * Freescale Kinetis:
 
      - Add kernel build support
      - Add support for the Kinetis L family of Cortex-M0+ MCUs.  Contributed
        by Alan Carvalho de Assis.

    * LPC17xx:

      - Now holds off sleep mode in the IDLE loop is DMA is in progress
        (because sleep mode will disable CPU SRAM).

    * LPC17xx Boards:

      - ZKIT-ARM-1769:  Now supports the ST7567 LCD display module.  Added
        an nxhello configuration for testing (Manikandan.S).
      - ZKIT-ARM-1769:  Add support for both CAN1 and CAN2.  Contributed by
        M.Kannan

      - Open1788: Basic support for the WaveShare Open1788 board is complete
        with working OS test, NSH, and graphics configurations.
      - Open1788: Integrated the LPC178x LCD driver with the WaveShare display.
        Touchscreen support is included, howerver, there appears to be an
        issue with the Open1788 touchscreen interrupt signal.
      - Open1788:  Now supports SDRAM (used to provide the LCD framebuffer).
      - Open 1788: Reversed sense of the IDLE LCD. It is now off when the
        LPC17 is sleeping and on when awake.  That is much a better visual
        indication of the dynamic CPU load

    * LPC17xx Drivers:

      - Added an LCD framebuffer driver for the LPC177x/8x family.
      - Implemented LPC17xx GPDMA support.
      - Integrated the LPC17xx GPDMA support into the SD card driver.
      - SSP driver adapted to work with the LPC178x family.
      - Separate LPC176x and LPC178x GPIO logic; this logic is too different
        to maintain in one file with conditional compilation.
      - Re-design of the GPIO logic for the LPC178x family by Rommel Marcelo.

    * LPC43xx:
 
      - Added kernel build support

    * STM32:

      - Added support for kernel mode build.
      - Added architecure support for the STM32 F427/F437 chips. Contributed
        by Mike Smith

    * STM32 Boards:

      - Added a configuration to support a kernel mode build of the OS test
        on the STM32F4Discovery

    * Stellaris LM3S/LM4F:

      - Added kernel build support
      - Added support for the 7 UARTs on the LM4F120

    * Stellaris LM4F Boards:

      - Added scripts and instructions to simplify use of OpenOCD with ICDI
        (JP Carballo)
      - The basic for the Stellaris LM4F120 Launchpad is complete.  This
        includes support for OS test and NSH configurations.  Additional
        driver development is needed.
 
    * Build System:

      - Directories where the same sources files are used to build different
        objects in the first and second pass kernel builds need to keep those
        objects in separate directories so that they are not constantly
        rebuilt.

    * Applications:

      - apps/system/ramtest:  Add a simple memory test that can be built
        as an NSH command.

    * Tools:

      - kconfig2html is a new tool which will replace the hand-generated
        documentation of the NuttX configruation variables with auto-
        generated documentation.

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 6.28.

    * A port to the Freescale Freedom KL25Z is complete but not yet stable
      enough.  The KL25Z is a low-cost Cortex-M0+ part with 128KB of FLASH
      and 16KB of SRAM.  This is is the effort of Alan Carvalho de Assis.

    * Conversion of old configurations to use the kconfig-frontends
      tool is an ongoing effort that will continue for some time.
      At this time, only 32% of the configurations have been converted
      to use the kconfig-frontends tools.

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

    * Tasking:

     - Fixed a critical bug:  When there is pending C buffered output
       and the system is very busy, the a pthread may be blocked at
       a critical point when trying to exit.  Blocking at this critical
       point would cause crashes.  All entire task/thread exit logic
       paths were reviewed and failsafe mechanisms were put in place
       to assure that exitting tasks never block after task teardown
       has been started.

    * ARMv6-M:

      - Fixed parameter passing for all system call inline functions with > 3
        parameters
      - Fixed a major problem:  The Cortex-M0 has no BASEPRI register but the
        logic of NuttX-6.26 was using it to manage interrupts.  Switch to
        using the PRIMASK instead.  This means that hardfaults will (again)
        occur when SVC instructions are executed

    * ARMv7-M:

      - Corrected Correct MPU sub-region settings for unaligned regions.
      - In exception handling with CONFIG_NUTTX_KERNEL, need to explicitly
        set and clear the privilege bit in the CONTROL
      - Fixed parameter passing for all system call inline functions with > 3
        parameters

    * Drivers:

      - Support for O_NONBLOCK was not supported in the "upper half"
        serial driver.
      - PL2303 compilation errors

    * Stellaris LM3S/4F:

      - Corrected typos in alternate function definitions.

    * LPC17xx Drivers:

      - Added a work-around for an ADC errata.  From Chris Taglia
      - Only one ADC pin was configured. Need to configure all that
        are in the ADC0 set.  From MKannan

    * File Systems:

      - The FAT logic was not making a distinction between directory
        non-existence and file non-existence so when it you try to
        create a file in a non-existent directory, it would create a
        file with the name of the missing directory.  Reported by Andrew
        Tridgell
      - Several fixes to the FAT file system from Ronen Vainish.  These
        fixes mostly involve the logic to extend directory clusters for
        the case of long file names but also include a few important
        general fixes (such as for storing 32 bit FAT values)
      - mkfatfs was writing the boot code to the wrong location.  From
        Petteri Aimonen

    * Networking:

      - Fixed a compilation error when socket options are are disabled.
        Reported by Daniel O'Connor

    * C Library:

      - Corrected an error in sscanf.  If %n occurs in the format statement
        after the input data stream has been fully parsed, the %n format
        specifier will not be handled.  Reported by Lorenz Meier
      - strchr(str, '\0') should return a pointer to the end of the string,
        not NULL.  From Petteri Aimonen

    * Build System:

      - Fix naming of NuttX target if EXEEXT is defined.

    * Applications:

      - OS test: Fix timing error in non-cancelable thread test.
      - NSH: Correct the test of the skip input parameter.  Was limiting the
        range to <= count.  From Ken Petit.