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ChibiOS Embeddedware Official Logo.jpg
Written inC, Assembly language
OS familyReal-time operating systems
Working stateStable
Source modelOpen source
Latest release19.1.3 / July 14, 2019; 4 months ago (2019-07-14)
Repository Edit this at Wikidata
PlatformsIntel 80386, ARM7, ARM9, ARM Cortex-M0, ARM Cortex-M3, ARM Cortex-M4, PowerPC, e200z, Atmel AVR, TI MSP430, STM8, Freescale Coldfire, Renesas H8S
Kernel typeMicrokernel
LicenseGPL3 or proprietary

ChibiOS/RT is a compact and fast[1] real-time operating system supporting multiple architectures and released under the GPL3 license. It is developed by Giovanni Di Sirio.


ChibiOS/RT is designed for embedded applications on 8, 16 and 32 bit microcontrollers; size and execution efficiency are the main project goals.[2] As reference, the kernel size can range from a minimum of 1.2 Kib up to a maximum of 5.5 KiB with all the subsystems activated on a STM32 Cortex-M3 processor. The kernel is capable of over 220,000 created/terminated threads per second and is able to perform a context switch in 1.2 microseconds on an STM32 @ 72 MHz. Similar metrics for all the supported platforms are included in the source distribution as test reports.


The ChibiOS/RT microkernel supports:

All system objects, such as threads, semaphores, timers, etc., can be created and deleted at runtime. There is no upper limit except for the available memory. In order to increase system reliability, the kernel architecture is entirely static, a memory allocator is not required (but is available as an option), and there are no data structures with upper size limits like tables or arrays. The system APIs are designed to not have error conditions such as error codes or exceptions.

The RTOS is designed for applications on embedded devices and includes demo applications for various microcontrollers:

Contributed ports are also available for the Coldfire and H8S families.[4]

ChibiOS/RT has also been ported to the Raspberry Pi[5] and the following device drivers have been implemented: Port (GPIO), Serial, GPT (General-Purpose Timer), I2C, SPI and PWM.

It is also possible to run the kernel in a Win32 process in a software I/O emulation mode, allowing easy application development without the need for physical hardware. An example is included for MinGW compiler.

ChibiOS/RT is supported by popular embedded TLS/SSL libraries such as wolfSSL.


ChibiOS/RT is fully supported by the GUI toolkit µGFX. µGFX was formerly known as ChibiOS/GFX.

See also[edit]


  1. ^ RTOS performance data on Archived 2013-01-11 at
  2. ^ ChibiOS/RT statistics on
  3. ^ A detailed explanation of multithreading in ChibiOS/RT
  4. ^ Additional supported architectures on Archived 2013-01-11 at
  5. ^ "ChibiOS/RT on the Raspberry Pi".

External links[edit]