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*** ChibiOS 17.6.0 Release Notes.                                          ***
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ChibiOS next is composed of several independent but inter-operable
sub-projects: RT, NIL, HAL, EX.

*** ChibiOS next highlights ****

This release is focused on RTOS general improvements, both RT and NIL received
a series of important improvements, new features have been added.

*** ChibiOS next general improvements ***

- Shared licensing headers under /os/licenses, now all products are handled
  by the same license include files.
- New ChibiOS/EX subsystems. EX sits on top of HAL and provides portable
  drivers for devices residing the MCU like MEMS, sensors, memories,
  displays etc.
- Shared RTOS components, now allocators, mailboxes and binary semaphores
  are usable by both RT and NIL.
  - Memory Pools now have a new variant named "Guarded Memory Pool" including
    a semaphore that guards the allocation function, the caller waits if there
    is not an object available in the pool.
  - Improved mailboxes, now it is possible to set a mailbox in a persistent
    reset state.
- FatFS 0.12b has been integrated.
- Rationalized source tree to reduce code duplication.
- New unit test library.
- Test suites have been rewritten using an unique code generation system
  starting from XML descriptions.
- Startup files have been separated from ports and licensed under Apache 2.0
  license, now it is possible to use ChibiOS startups and ld files in projects
  without RT, NIL, HAL or EX.
- Improved GCC ld scatter files with multi RAM/Flash regions capability.
- GCC makefiles system improvements.
- Support for all new Nucleo and Discovery boards from ST.
- CMSIS updated to version 4.50.
- Enhanced shell with history and quoted parameters. Common commands have
  beed included in a shared module in order to avoid duplication in the
  various demos.

*** What's new in RT/NIL ports ***

- Common ports architecture. Now RTOS ports work for both RT and NIL, no
  more code duplication. Ports are now also licensed for both NIL and RT.
- MPU use for hardware stack checking in ARMCMx port.

*** What's new in RT 4.0.0 ***

- Now uses the common ports architecture.
- Now uses the new shared RTOS components.
- New threading API, now creating static threads is even faster.
- Extended priority range from 1..127 to 1..255.
- Enhanced dynamic threading, safer and easier to use.
- Enhanced Registry, it is now possible to find threads by name, by pointer
  or by working area.
- Enhanced trace buffer, it is able to store events regarding not just threads
  but also IRQs, halts and user events. The trace record now stores both the
  "slow" system time and a RT stamp for increased accuracy.
- New kernel hooks for a more flexible code instrumentation.
- Removed I/O queues, now the HAL has an improved equivalent.
- Experimental NASA OSAL implementation.
- Posix simulator added.

*** What's new in NIL 2.0.0 ***

- Now uses the common ports architecture.
- Now uses the new shared RTOS components.
- Added implementation of thread queues directly in the kernel, removed it
  from NIL OSAL.
- All new features are optional so there is no code size increase.
- Enhanced source-level compatibility with RT.
- Enhanced debug features.
  - State checker like in RT.
  - Parameters checks like in RT.

*** What's new in HAL 5.0.0 ***

- Improved serial driver.
  - It is possible to set a different buffer size for each port.
  - SW overruns and HW overruns now have a separate event flag.
- Events handling in the PAL driver. Now it is able to support interrupts
  handling and callbacks.
- EXT driver is still supported but marked as deprecated.
- New interface for flash devices (used by EX).
- New interfaces for accelerometer, barometer, compass, gyroscope,
  hygrometer and thermometer devices (used by EX).
- Added an I2C bit banged driver as fall-back for faulty hardwares.
- Improved OSAL architecture with shared sub-modules.
- All file names have been prefixed by "hal_" in order to prevent collisions
  with 3rd parties files. This should make integration of external libraries
  much easier.
- Improved behavior of HAL queues, now the timeout is absolute not just an
  inter-byte timeout.
