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)