ReleaseNotes

    * Memory Management:

      - Granule Allocator:  (1) Add a new function to reserve un-allocatable
        regions in the granule heap.  (2) Add interfaces to support
        un-initializing a granule allocator.
      - Page Allocator:  Add a simple physical page allocator based on the
        existing NuttX granule allocator.  I am not certain if the granule
        allocator is sufficiently deterministic for long range use, but it
        gets get a page allocator in place for testing very quickly.
      - Remove CONFIG_MM_MULTIHEAP.  Non-multiheap operation is no longer
        supported.
      - sbrk():  sbrk() is now supported in the kernel build to permit
        dyanmically sized, per-process heaps.
      - Per-Process Heaps:  Space at the beginning of the process data space
        is now reserved for user heap management structures.  In the kernel
        build mode, these heap structures are shared between the kernel and
        use code in order to allocate user-specific data.
      - User Heap Management:  When a privileged thread exits, we have to
        use the kernel allocator to free memory; when an unprivileged thread
        exits, we don't have to do anything... heap memory will be cleaned
        up when the address environment is torn down.
      - Inter-Process Shared Memory Support:  (1) Add implementation and
        documentation for shmget(), shmctl(), shmat(), and shmdt().  (2)
        Add system system calls to support the user call gate to the shared
        memory interfaces.  (3) Add platform-specific interface definitions
        needed to support the shared memory feature.
      - Virtual Page Allocator:  Add support for a per-process virtual page
        allocator.  This is a new member of the task_group_s structure.  The
        allocator must be initialized when a new user process is started and
        uninitialize when the process group is finally destroyed.  It is
        used by shmat() and shmdt() to pick the virtual address onto which
        to map the shared physical memory.

    * File Systems/Block Drivers/MTD:

      - SMART FS and SMART FS procfs updates from Ken Pettit.
      - The MTD Read-ahead/Write buffer layer appears is now functional.

    * Binary Formats:

      - Add logic to initialize the per-process user heap when each user
        process is started.

    * Graphics:

      - Change all occurrences of NxConsole to NxTerm.

    * Networking:

      - PHY Interrupts: (1) Standardize a PHY interrupt attachment
        interface. (2) Add support for an ioctl that can be used to notify
        an application when there is a change in the network status
        signalled by a PHY interrupt.
      - Improved Send Logic:  In the past, the first packet send to a new
        network peer would fail; there would be no entry in the ARP table
        for the peer and so an ARP request qould replace that first packet.
        Now as an option if CONFIG_NET_ARP_SEND=y, all send logic will (1)
        check if the peer MAC address is in the ARP table and, if not, (2)
        send ARP requests periodically to get the mapping and (3) wait for
        the ARP response.  Then (4) when the ARP response is received then
        the actual send logic will be initiated.  Thus there may be a delay
        with the first packet sent to a new peer, but the packet should not
        be lost

    * Host Simulation:

      - Emulated SPI FLASH driver for the sim target from Ken Pettit.

    * Intel x86:

      - The default host is now x86_64 and the -m32 option will be
        automatically selected for simulation builds.

    * Intel 8051 Family:

      - Removed all support for the 8051 family architecture from the NuttX
        source tree.  The obsoleted code along with the removal patch can
        now be found at misc/Obsoleted/.  This code was removed because (1)
        although some functionality has been demonstrated, I am not aware of
        any really successful ports of NuttX to any 8051, and (2) the 8051,
        with its hardware stack, forces limitations and complications to the
        other architectures and make growth and development of NuttX more
        complex.

    * ZiLOG ZNeo Boards:

      - configs/16z:  Support for this board has been removed from the NuttX
        source tree (but still can be found in the misc/Obsoleted
        directory). This port is not ready for usage but may return to the
        NuttX tree at some point in the future.

    * Atmel SAM3/4 Boards:

      - SAM4E-EK: Add (1) a fully-functional ILI9341-based LCD driver and
        (2) a fully-functional NxWM configuration.

    * ARMv7-A:

      - Address Environments:  Add support for application address
        environments using the Cortex-A MMU.  Implement standardized
        platform-specific interfaces of NuttX address environment
        support.
      - Cache Operations:  Implement standardized, platform-specific cache
        operations.  These are called from the ELF loader in order to flush
        D-cache and invalidate I-cache after an ELF module has been loaded
        into memory. With this change, ELF modules work correctly on the
        SAMA5/Cortex-A platform.
      - Kernel Build: (1) Add implementations of system call gate. (2) Add
        CRT0 start-up file that can be linked with separately built user
        programs.  (3) Add support for delivery of use-mode signals in the
        kernel build.  (4) Add logic to initialize the per-process user heap
        when each user process is started.  (5) ARMv7-A exception handling
        needs to work a little differently if we support user mode
        processes.  This is because R13 and R14 are paged differently
        between user and SVC mode.
      - Shared Memory Support:  (1) Add logic necessary to handle remapping
        of shared memory on context switches.  (2) Extend virtual/physical
        address conversions to include addresses in shared memory.  (3) Add
        implementation of platform-specific shared memory support.

    * Atmel SAMA5D Drivers:

      - Implement all network ioctls, including the new ioctl to setup PHY
        event notifications.
      - In kernel build with address environment, need logic to map user
        virtual addresses to physical addresses, and vice versa.

    * Atmel SAMA5D Boards:

      - SAMA5D3 Xplained, SAMA5D3-EK, and SAMA5D4-EK:  Convert existing
        board specific PHY interrupt interfaces to use newly defined
        standard interface.
      - SAMA5D4-EK: Add a configuration for testing the kernel build
        configuration.  There are configurations to boot either from an SD
        card or from and in-memory ROMFS file system.
      - SAMA5D4-EK: Add documentation/support for Rev E. board.

    * STMicro STM32 Drivers:

      - Ethernet: Modified to support the change to the network ioctl
        signature changes.  Also add support for new ioctl to setup PHY
        event notifications.

    * STMicro STM32 Boards:

      - STM32F4Discovery with STM32F4DIS-BB: Add a network enabled NSH
        configuration for the STM32F4Discovery board with the STM32F4DIS-BB
        base board installed.  Includes support for the microSD card slot on
        the STM32F4DIS-BB base board.

    * TI Tiva Drivers:

      - Add support for the TI CC3200. From Jim Ewing.

    * TI Tiva Boards:

      - Add support for the TI CC3200 Launchpad. From Jim Ewing.

    * C Library:

      - Re-implemented poll() delay using sem_timedwait().

    * Configuration/Build System:

      - Export Target:  In the kernel or protected builds, (1) only the user
        libraries should be exported,  (2) do not copy internal header files
        or build scripts if this is a kernel or protected build, and (3)
        needs to bundle up the user C startup file (crt0), not the kernel
        head object for the kernel and protected builds.
      - Add logic that will permit us to build user libraries with different
        CFLAGS than kernel code.  This is needed because we need the
        -fno-common option when building ELF code to prevent SHN_COMMON
        relocations.

    * Applications:

      - NSH:  Extend the NSH network initialization logic.  There is now an
        option that will create a network monitor thread that will monitor
        the state of the link.  When the link goes down, the code will
        attempt to gracefully put the Ethernet driver in a down state; When
        the link comes back, the code will attempt to bring the network back
        up.
      - ELF Example:  The ELF test/example has been extended so the
        individual ELF test programs can link against the SYSCALL library
        (if it is available) or against the C library to eliminate or
        minimize the need for symbol tables.
      - Change all occurrences of NxConsole to NxTerm.
      - MTDRWB Example:  Add an example to test MTD R/W buffering.
      - OS Test Example:  Add a trivial test of sem_timedwait.

    * Application Configuration/Build System:

      - Import Target:  (1) Add logic that will allow building applications
        against a NuttX export package (vs. the nuttx/ source tree).  (2)
        Add .config file to export package.  (3) Create apps/import.  Create
        apps/import/Make.defs that does things like define CFLAGS; ELF build
        requires -fno-common in CFLAGS. Copy some base logic from
        nuttx/tools/Config.mk to apps/import/Make.defs.  (4) Add
        apps/import/scripts/gnu-elf.ld GCC linker script for ELF import
        builds.
      - All Makefiles:  (1) Add an install target to all makefiles.  For
        the import build, the top-level Makefile now does two passes: (1)
        builds libapp.a, then (2) installs the programs into apps/bin.  (2)
        Add program installation for CONFIG_BUILD_KERNEL in all Makefiles
        that build a main().  (3) For kernel build, the object file
        containing main cannot go into library because of name collisions.
        The object file must be handled as a special case in every Makefile.
      - All Built-In Programs:  With kernel build (CONFIG_BUILD_KERNEL),
        entry point to all tasks is main(), not some xyz_main().
      - NSH: Several commands must be disabled in the kernel build because
        they depend on interfaces that are not available outside of the
        kernel: dd, df, losetup, mkfatfs, mkdr, and ps.
      - apps/tools/:  (1) Add mkimport.sh to expload an NuttX import package
        and install in apps/import.  (2) Add mkromfsimg.sh  script to create
        a BOOT ROMFS filesystem image.
      - ELF and NxFLAT Examples: Do not build test cases that use
        task_create() if there is an address environment.

    * Tools:

      - refresh.sh: Add a tool to make refreshing configurations easier
        when you want to do a lot of them.
      - mksyscall.c: Build syscalls that do not need header files.
      - mkexport.sh: Add .config file to export package.
      - See above for new apps/tools scripts.

Efforts In Progress.  The following are features that are partially
implemented but present in this release.  They are not likely be be
completed soon.

    * Processes.  Much of the work in this release is focused on the
      realization of Unix-style user processes in NuttX.  There is more to
      be done, however.  The full roadmap and status is available at:
      http://www.nuttx.org/doku.php?id=wiki:nxinternal:memconfigs#the_roadmap_toward_processes

    * XMega:  There are some fragments in place for an XMega port.  That
      port has not really started, however.

    * Galileo:  Similarly, there are fragments in place for an Intel Galileo
      port.  The port not been started in earnest either.

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:

      - Kernel build fixes: (1) IDLE TCB setup needs to indicate that the
        IDLE thread is a privileged, kernel thread.  (2) Don't build
        task_create() or task_spawn() interfaces if there is an address
        environment.  (3) posix_spawn() kernel proxy thread should be a
        kernel thread, not a user task.
      - Several pthread interfaces: Add const storage class to to phthread
        parameters.  From Freddie Chopin.
      - sched/clock: Remove vestiges of g_tickbias;  need, instead, to apply
        time bias to g_basetime in order to provide the correct system time.
      - System Calls:  (1) Several typos fixed; corrected integration of
        exevc(), execvl(), posix_spawn, and posix_spawnp system calls. (2)
        If we are configured to use a kernel stack while in SYSCALL handling,
        then we need to switch back to the user stack to deliver a signal.

    * File Systems/Block Drivers/MTD:

      - procfs: Fix some procfs breakage introduced by reorganizing some
        non-reorganizable data structures.  From Ken Pettit.
      - AT45: In at45db_bwrite , the buffer is not increased when writing
        more than 1 page.  Sourceforge bug #34.

    * Binary Formats:

      - ELF relocations.  Some relocation types do not have a named symbol
        associated with them.  The design did not account for that case.
      - ELF Loader: Critical bugfix.. BSS was not being cleared.

    * Memory Management:

      - Granule allocator initialization uses wrong allocator to setting
        aside kernel memory.
      - Add a flag to group structure:  If the group is created by a kernel
        thread, then all resources in the group must be privileged.

    * Cryptogrphic Support:

      - crypto/cryptodev.c: Path segments reversed in include file path. Noted by Brennan Ashton.

    * Common Drivers:

      - Common CAN upper-half: In can_txdone, waiters on the semaphore
        should be informed regardless of the return value of can_xmit. First
        it returns -EIO if there are no new packets, and second the
        information of the waiters is about the last transferred packet.
        From  Daniel Lazlo Sitzer.

    * ARM:

      - System Calls: Fix a typo in system call when fetching parameter from
        the stack:  regs[REG_PC]+4 is the address, not regs[REG_PC+4].

    * STMicro STM32 Drivers:

      - STM32 F401 UART: Correct support for USART6 on this chip.  From
        Freddie Chopin.
      - STM32 FLASH fixes: use size_t instead of uint16_t, make interface
        more generic.  From Freddie Chopin.
      - Fix for UART7 and UART8 on STM32 clock enable from Aton.
      - CAN: At the end of the interrupt handler, the interrupts were being
        disabled, if all packets have been transferred when the interrupt
        handler was invoked. This is problematic, because the interrupt
        handler calls can_txdone of the upper half which can enqueue new
        packets to send. Removed the block altogether, because can_txdone
        calls can_xmit which disables interrupts if there are no new packets
        to send.  From  Daniel Lazlo Sitzer.
      - Additional STM32 CAN correction suggested by Max Holtzberg.

    * STMicro ST32 Boards:

      - configs/mikroe-stm32f4: Fix a few compile bugs and minor corrections
        to the mikroe-stm32f4 configuration source.  From Ken Pettit.

    * ARM9/ARMv7-A:

      - System Calls: Fix ARM7/9 and Cortex-A SYSCALLs:  For threads in SVC
        mode, the SVC instructions clobbers R14.  This must be taken account
        in the inline assembly.
      - Task Setup:  All tasks, even user mode tasks, must start in
        supervisor mode until they get past the start-up trampoline.
      - ARMv7-A:  Modify up_fullcontextrestore() for CONFIG_BUILD_KERNEL.
        It changed CPSR while in kernel.  That will crash if the new CPSR is
        user mode while executing in kernel space.  Fixed by adding a
        SYS_context_restore system call.  There is an alternative, simpler
        modification to up_fullcontextrestore() that could have been done:
        It might have been possible to use the SPSR instead of the CPRSR and
        then do an exception return from up_fullcontextrestore().  That
        would be more efficient, but I never tried it.

    * Atmel SAM3/4 Boards:

      - SAM3X/Arduino Due: Fix typo in sam3x_periphclks.h; add SCLK
        definitions to board.h header file.  From Fabien Comte.
      - SAM3 RTT: Only SAM4 family has RTTDIS bit in the MR register.
        SourceForge bug #33 from Fabien Comte.

    * C Library:

      - sscanf(): NuttX libc tried to guess how many characters to parse,
        extracted them into a buffer, then ran strtol() on that buffer.
        That guess was often wrong.  A better approach would be to call
        strtol() directly on the input data, using the endptr return value
        to determine how many characters to skip after parsing.  From Kosma
        Moczek.
      - Corrected atan2 implementations from Denis Arnst.
      - Change to lib_dtoa() to fix precision error from trailing zeroes.
        From Bob Doiron.

    * Applications:

      - Fix NSH PS command:  If there are no arguments, it could print
        garbage for argument list.

    * Configuration/Build System:

      - Null Example:  Need to include config.h it order know if this is or
        is not a kernel build.  This problem still exists in several other
        file that may need to define main().