avrtos v2.1.0: Polling API

Main Features

• Polling API:
  Introduced polling API allowing threads to wait on multiple kernel objects simultaneously:
  • New k_poll() function to wait for events on semaphores, mutexes, FIFOs, and message queues
  • CONFIG_POLLING configuration option to enable/disable polling support
  • Add an example (poll) demonstrating polling with multiple kernel objects: https://github.com/lucasdietrich/AVRTOS/blob/main/examples/poll/main.c

Minor Changes

• Added pointer coloring macros for AVR architectures to embed color values in unused pointer bits:
• Exposed z_ker and z_main_thread as external symbols for advanced use cases
• Improved Dining Philosophers example for Arduino framework

Full Changelog: v2.0.0...v2.1.0

avrtos v2.0.0: Rust Experimental Support, Memory Allocators, and More

Main Features

• Rust Support (Experimental):
  Introduced experimental support for Rust, including:

  • Automatic bindings generation via build.rs
  • Basic thread API wrappers and kernel integration
  • Examples for thread creation, stdio, and memory allocation:
    build rust hello world with cargo run --example hello_world --release

• Memory Allocation API (Experimental):

  • Introduced a slab allocator and helper functions
  • Added bump allocator and optional malloc-like interface (CONFIG_USE_STDLIB_HEAP_MALLOC_MAIN)
  • Added allocator-related samples and integration with Rust global allocator

• Thread Join Support:

  • Added support for k_thread_join() and corresponding example

• Signal Handling (Draft):

  • Initial support for synchronization primitives and signals in both C and Rust

• Standard I/O Improvements:

  • Added support for stdin with example
  • Updated stdio configuration:
    • CONFIG_STDIO_USART (default: USART0)
    • Deprecated: CONFIG_STDIO_PRINTF_TO_USART

Bug Fixes

• Fixed kernel panic in mem_slab caused by improper wake-up handling
• Fixed thread creation to ensure address stability throughout thread lifetime
• Fixed warnings in slab allocator (slist_count)
• Fixed k_mem_slab_init() return value and removed outdated functions
• Fixed compilation issues due to LLVM/Rust struct handling bug (k_timeout_t)
• Corrected warnings for Arduino IDE compatibility
• Resolved issue with z_pend_current_on() leaving expired threads in queues

Improvements

• Improved project structure and documentation
• Updated developer.md, reformatted README with Rust details
• Added debug configuration improvements and enforced formatting
• Updated parse_size_txt.py to support Berkeley format (GCC 14.2.0)
• Adapted avr-size flags based on detected avr-gcc version
• Updated code metrics script
• Updated PlatformIO configuration and targets

Minor Changes

• Removed "cc" build dependency for Rust examples
• Changed tabs to spaces across codebase
• Removed forced default of CONFIG_KERNEL_ASSERT = 0
• Renamed k_thread_stop() and k_stop() to k_thread_abort() and k_abort()
• Added sleep, yeet, and critical section APIs
• Added CONFIG_KERNEL_TIME_API_MS_PRECISION and improved timer functions
• Deprecated public k_work_submittable API
• Added internal macros like Z_THREAD_MAIN_PRIORITY and Z_THREAD_MAIN_STACK_END_ADDR
• Cleaned up dead code and removed unused file descriptor implementation

Full Changelog: v1.3.1...v2.0.0

avrtos v2.0.0: Major Update with Rust Support, Memory Allocators, and More

Main Features

• Rust Support (Experimental):
  Introduced experimental support for Rust, including:

  • Automatic bindings generation via build.rs
  • Basic thread API wrappers and kernel integration
  • Examples for thread creation, stdio, and memory allocation

• Memory Allocation API (Experimental):

  • Introduced a slab allocator and helper functions
  • Added bump allocator and optional malloc-like interface (CONFIG_USE_STDLIB_HEAP_MALLOC_MAIN)
  • Added allocator-related samples and integration with Rust global allocator

• Thread Join Support:

  • Added support for k_thread_join() and corresponding example

• Signal Handling (Draft):

  • Initial support for synchronization primitives and signals in both C and Rust

• Standard I/O Improvements:

  • Added support for stdin with example
  • Updated stdio configuration:
    • CONFIG_STDIO_USART (default: USART0)
    • Deprecated: CONFIG_STDIO_PRINTF_TO_USART

Bug Fixes

• Fixed kernel panic in mem_slab caused by improper wake-up handling
• Fixed thread creation to ensure address stability throughout thread lifetime
• Fixed warnings in slab allocator (slist_count)
• Fixed k_mem_slab_init() return value and removed outdated functions
• Fixed compilation issues due to LLVM/Rust struct handling bug (k_timeout_t)
• Corrected warnings for Arduino IDE compatibility
• Resolved issue with z_pend_current_on() leaving expired threads in queues

Improvements

• Improved project structure and documentation
• Updated developer.md, reformatted README with Rust details
• Added debug configuration improvements and enforced formatting
• Updated parse_size_txt.py to support Berkeley format (GCC 14.2.0)
• Adapted avr-size flags based on detected avr-gcc version
• Updated code metrics script
• Updated PlatformIO configuration and targets

Minor Changes

• Removed "cc" build dependency for Rust examples
• Changed tabs to spaces across codebase
• Removed forced default of CONFIG_KERNEL_ASSERT = 0
• Renamed k_thread_stop() and k_stop() to k_thread_abort() and k_abort()
• Added sleep, yeet, and critical section APIs
• Added CONFIG_KERNEL_TIME_API_MS_PRECISION and improved timer functions
• Deprecated public k_work_submittable API
• Added internal macros like Z_THREAD_MAIN_PRIORITY and Z_THREAD_MAIN_STACK_END_ADDR
• Cleaned up dead code and removed unused file descriptor implementation

Full Changelog: v1.3.1...v2.0.0-pre

avrtos v1.3.1 (fix arduino samples build)

Key features:

• Fix Arduino samples build

Initial release v1.3.0

Full Changelog: v1.3.0...v1.3.1

avrtos v1.3.0

Key Features:

• (experimental feature) New MCP2515 CAN driver: Introduced a new CAN driver for
  the MCP2515 controller,
  enabling CAN bus communication over SPI. Introduce CONFIG_DEVICE_MCP2515
  configuration option to enable or disable the MCP2515 driver.
• Documentation Overhaul: Improved documentation across multiple modules, including
  mutexes, semaphores, signals, FIFOs, flags, standard I/O, system time, timers,
  events, atomic operations, idle thread, and various kernel headers.
• Kernel State Structure: Introduced the z_kernel structure to centralize all
  kernel state variables.
• Thread Sleep Improvement: Reworked the z_pend_current() function and modified
  k_sleep() to utilize it.
• Semaphore Enhancement: Added k_sem_cancel_wait() function to allow cancellation
  of threads waiting on a semaphore.
• Renamed macros:
  • Configuration Options Renaming
    • Renamed several configuration macros for better consistency and clarity:
      • CONFIG_KERNEL_DEBUG to CONFIG_KERNEL_SYSCLOCK_DEBUG=0
      • CONFIG_KERNEL_TIME_SLICE_TICKS to CONFIG_KERNEL_TIME_SLICE_US
      • K_EVENTS_PERIOD_TICKS to Z_EVENTS_PERIOD_TICKS
      • K_TIMERS_PERIOD_TICKS to Z_TIMERS_PERIOD_TICKS
  • SPI Driver Update: Renamed spi_mode_t to spi_role_t and introduced a new
    spi_mode_t for better clarity in the SPI driver.

Minor changes:

• New Sample: Introduced a hello-world sample to help new users
  get started quickly.
• Function Relocation: Moved uptime functions to the systime.c file.
• UART Configuration: Changed the default UART baud rate to 115200 bps for
  consistency across the platform.
• QEMU Configuration: Defined icount auto in QEMU settings.
• Makefile Upload Behavior: Adjusted the Makefile to flash the most recently
  built sample when uploading

Bug fixes:

• I2C Driver Frequency Calculation Fix: Corrected the FREQ_CALC macro to ensure
  accurate frequency settings in the I2C driver.
• Timer Driver Function Correction: Fixed ll_timer16_start() and introduced
  ll_timer16_get_tcnt().
• Workqueue Module Macro Fix: Fixed the K_WORK_DELAYABLE_INIT macro and
  reintroduced z_delayable_work_trigger() to restore delayable workqueue functionality.
• Kernel Synchronization:
  • Scheduler Lock Improvement: Modified the kernel to lock the scheduler only
    if it is not already locked, preventing potential deadlocks.

Full Changelog: v1.2.1...v1.3.0

avrtos v1.2.1

Key features:

• I2C:
  • Introduce function i2c_master_write_read() enabling to write and
    read data in a single transaction.
  • Rename i2c_master_transmit()) to i2c_master_write().
  • Rename i2c_master_receive() to i2c_master_read().
  • Add option to configure the speed of the I2C bus on initialization.

Minor changes:

• Introduce CONFIG_KERNEL_REENTRANCY configuration option to enable/disable
  reentrancy support for kernel objects, such as mutexes and sched lock/unlock.
• Change code style, update .clang-format and format the codebase.
• Improve stack sentinel verification by introducing a thread monitoring mecanism.
• Introduce CONFIG_THREAD_MONITOR and CONFIG_THREAD_MAIN_MONITOR configuration
  options to enable/disable thread monitoring.
• Introduce CONFIG_THREAD_STACK_SENTINEL_AUTO_VERIFY configuration option to
  enable/disable automatic stack sentinel verification.
• Improve timers subsystem.

Bug fixes:

• Fix returned error code in i2c_master_write() and i2c_master_read().
• Fix K_MSEC macro with big values of CONFIG_KERNEL_SYSCLOCK_PERIOD_US.
• Fix K_WORK_DELAYABLE_INIT macro.

Full Changelog: v1.2.0...v1.2.1

avrtos v1.2.0

Key Features:

• I2C: Introduced a comprehensive I2C driver, and a minimal TCN75 device driver.
• SPI Driver Refactor: Enhanced the SPI driver by introducing the spi_regs intermediate structure, which holds SPI registers.
• Work Queue: Added support for delayable work queue items, with a sample demonstrating this feature.

Minor Changes:

• Stored MCUSR at startup using the CONFIG_KERNEL_MINICORE_SAVE_RESET_CAUSE option.
• Introduced new configuration options:
  • Management of reset cause with CONFIG_KERNEL_MINICORE_SAVE_RESET_CAUSE and CONFIG_KERNEL_CLEAR_WDT_ON_INIT.
  • Addition of an idle hook through CONFIG_IDLE_HOOK.
  • Enabling of the delayable work feature with CONFIG_WORKQUEUE_DELAYABLE.
  • CONFIG_SERIAL_AUTO_INIT.
  • Banner configuration options CONFIG_AVRTOS_BANNER_ENABLE and CONFIG_AVRTOS_BANNER.
  • Various options for the I2C driver.
• Updated samples and documentation.
• Removed unused USART functions and eradicated obsolete code.
• Moved assembly files to src/arch.
• Improved overall error code returns and extended support for CONFIG_KERNEL_ARGS_CHECK.

Bug Fixes:

• Fixed CONFIG_KERNEL_AUTO_INIT with the Arduino framework by utilizing the initVariant() function.

Documentation and Samples:

• Enhanced documentation.
• Added new samples demonstrating various features:
  • MCP3008 and TCN75 driver samples.
  • Arduino sample MinimalExample.

Full Changelog: v1.1.0...v1.2.0

avrtos v1.1.0

Main features:

• SPI: Added SPI drivers for master and slave with full support for atmega328p
  and atmega2560.
• SPI: Added two samples to demonstrate communication between master and slave
  (with data rate and error measurement).
• DevOps: Added Dockerfile and Jenkinsfile for CI/CD.

Bug Fixes:

• Corrected bad characters in a preprocessor #error message.
• Resolved anomalies in the implementation of k_flags_notify() consequently,
  refined the flags sample.
• IRQ are now always enabled when exiting k_thread_stop(), this adjustment
  ensures threads can be safely resumed using k_thread_start().
• Fixed a bug in QEMU preventing to use all timers (patch submitted and attached
  here).

Improvements:

• Improved time functions: introduced k_wait allowing to wait for a specific
  time in a particular mode. Added support for millisecond precision in time API
  through CONFIG_KERNEL_TIME_API_MS_PRECISION.
• Updated and improved documentation.
• Optimized headers inclusions.

Minor changes:

• Introduced K_TICKS to declare timeouts in ticks.
• Introduced macros: FEATURE_TIMER_COUNT and FEATURE_USART_COUNT to ascertain if
  an example can be built for a certain toolchain.
• Enhanced disassembly script for PlatformIO.
• k_work_submittable removed from public API, but k_workqueue_create was added
  to the Arduino keywords list.
• Added sample for testing a single timer.
• Enhanced cmake targets with better ninja support, making ninja the default
  generator.
• Introduced a script for computing code metrics.
• Dead code was purged.
• Help added for thread-ev-spawn example.
• Defined internal macros: Z_THREAD_MAIN_PRIORITY and
  Z_THREAD_MAIN_STACK_END_ADDR.
• Eradicated unused/unfished file descriptor features (fd.c/fd.h).
• Eliminated /______/ code boundaries.

Full Changelog: v1.0.0...v1.1.0

avrtos v1.0.0

AVRTOS is a real-time operating system (RTOS) designed specifically for 8-bit AVR microcontrollers. The project aims to provide an efficient and highly configurable RTOS solution for AVR-based systems. Fully C/C++ compliant, AVRTOS is compatible with the AVR-GCC toolchain, Arduino and PlatformIO frameworks.

Key Features:

• Cooperative and preemptive threads
• Round-robin scheduling without priority support
• Configurable system clock
• Synchronization objects (mutexes, semaphores, workqueues, etc.)
• Drivers for UART, timers, GPIO, and external interrupts
• Thread sleep and scheduler lock/unlock
• Runtime object creation
• Thread canaries and sentinel stack protection
• Events and timers
• Atomic API, logging subsystem, and Uptime API
• Various data structures
• Thread naming, pseudo random number generator, and debug/utils functions

Supported AVR Architectures:

• AVR5: Tested on ATmega328p (Arduino PRO)
• AVR6: Tested on ATmega2560 (Arduino Mega2560)

Full Changelog: https://github.com/lucasdietrich/AVRTOS/commits/v1.0.0

Full Changelog: https://github.com/lucasdietrich/AVRTOS/commits/v1.0.0