Embedded & IoT Operating Systems

Overview and resources for various real-time and embedded operating systems.

General Information

• Wikipedia - Real-time Operating System (RTOS)
• Wikipedia - Comparison of RTOS
• Top IoT Operating Systems and Microsoft (Medium)
• Open Source IoT Operating Systems (HackerEarth)

Major Embedded OS/RTOS

• FreeRTOS (MIT)
  • Active support for ARM, AVR, AVR32, ColdFire, IA-32, Cortex-M, MSP430, PIC, STM32, etc.
  • Official Site
• RIOT OS (LGPL)
  • Supports ARM, MSP430, AVR, x86.
  • Official Site
• Apache Mynewt (Apache 2.0)
  • Supports ARM Cortex-M, MIPS32, PIC32, RISC-V.
  • Official Site
• Zephyr Project (Apache 2.0)
  • Supports x86, ARM, ARC, NIOS2, XTensa, RISC-V.
  • Official Site

Android Things (Brillo)

• Official Android Things Page
• Things Console
• Android Things Internals (PDF)

Internals & Daemons

• /system/bin/peripheralman: C++ System Service for peripheral I/O.
• dumpsys com.google.android.things.pio.IPeripheralManager
• Peripheral Manager Source
• peripheral_io.h: The header for the new HAL.
• HAL Path: /system/lib/hw/peripheral_io.<board_name>.so

Device Classes & Protocols

• Classes: Vibrator, Battery, Audio, Modem, Bluetooth, Camera, IR, Display, GPS, Lights, NFC, Sensors, Wifi.
• Greybus Device Classes: standardizing communication.
• Protocols: USB, GPIO, SPI, UART, PWM, I2C, SDIO.