About {#about}

MKernel is embedded RTOS, based on microkernel architecture. It's designed for ARM microprocessors, however, can be easily ported to any 32bit MCU.

Features

• BSD License, royalty free, open source.
• Tickless. For system scheduling used 1 HPET timer and RTC. If RTC is unavailable, another HPET timer can be used for RTC emulation (with full RTC functionality)
• Hardware abstraction.RTOS is providing common interface for drivers.
• Standart microkernel syncronization: mutexes, events, semaphores, queues.
• Nested mutex priority inheritance
• Embedded dynamic memory manager, with ability of nested memory pools for threads, dedicated system pool. Aligned malloc calls inside of any pools
• Safe and MPU ready. All supervisor-specific calls are wrapped around swi/svc calls for context rising.
• Embedded libraries:
  • printf/sprintf. Around 1k of code.
  • time routines. POSIX-light
  • single-linked list, double linked list, ring buffer, block ring buffer
  • random number generation: hardware (if supported) or software
• Error handling:
  • kill thread on system error, print error, if configured
  • restart system on critical error, memory dump if configured
  • handle error exceptions, decode address (if supported) and exception code
• Lot of debug features:
  • memory dumps
  • object marks
  • thread profiling: name, uptime, stack allocated/current/used
  • memory profiling: red-markings, pool free/allocated size, objects fragmentation
  • stack profiling: supervisor allocated/current/used. Plus for arm7 - irq, fiq, abt
  • configurable debug console
• Supported hardware:
  • ARM7
  • cortex-m3, drivers for:STM32 F2 (gpio, uart, rcc, timer, dma, rand)

Cortex-M3 features:

• Native SVC and pendSV support

ARM7 features:

• Nested interrupts
• FIQ support
• pendSV emulation, when returning to user/system context

History

0.1.5

• sd card module (STM32F2)
• usb core module (STM32F2)
• usb device module (STM32F2)
• SCSI block module
• USB mass storage class

0.1.4

• new module: software timers, running in independent thread
• keyboard module new functions: keyboard_wait_for_key, keyboard_has_messages ! exception handling improved:
  • detection of caller context (SYS/thread), instruction address, caused problem
  • if thread context, thread will be terminated, if SYS, system will be restarted
  • SVC call while interrupts are disabled error decoded and processed, instead of general hard fault
  • configurable option to halt system on fatal error, instead of rebooting

0.1.3

• pin keyboard module with debounce logic ! sys_alloc, sys_alloc_aligned, sys_free now supported in SYS context
• push method for debug console

0.1.2

• added examples for STM32 F2
• optimized software rand
• renamed all .s to .S

0.1.1

• added support of software random number generation
• added support for STM32 F2 HW RNG
• srand() by default in startup

Contacts

Author: Alexey Kramarenko, alexeyk13@yandex.ru