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prerequisite scions for lepton operating system construction (python 3, windows 7 or more recent). STILL UNDER CONSTRUCTION

  1. Install scion tool: pip install git+

  2. Open windows console with administrator rigths.

  3. Create lepton rootstock: scion rootstock-install c:/lepton/scion-install

  4. Plant the seed of the lepton graft seeds: scion seed-add

  5. Grow the lepton source tree with the grafts: scion graft


Initial version of lepton scion

Lepton is an open source POSIX "compliant" Operating System for deeply embedded devices. It tries to bring PSE-53 POSIX capabilities to embedded world (including multiprocess, filesystems, IP stacks, BSD socket, messages queues, ...). The system implementation follows an UNIX approach. Unix « philosophy". Everything is file. Everything is a stream of bytes.

The aim of this project, it's not to develop another operating system like GNU/Linux, but an human understandable operating system that provides more services than a realtime kernel, while keeping a reasonable footprint for deeply embedded system.

We hope Lepton will be able to help anybody to develop their personal, school or professional projects easily and quickly.

We are ready to accommodate contributions to improve Lepton and support new features.

Supported platforms: -. ARM Cortex-M7: Atmel SMART SAM V71 Xplained Ultra (Atmel) -. ARM Cortex-M4: STM32F4 Discovery (ST stm32F407) -. ARM Cortex-M4: STM32F4 nuodio project (ST stm32F429) -. ARM Cortex-M4: Olimex P407 (ST stm32F407) -. ARM Cortex-M0+: ATSAMD20 Xplained Pro (Atmel) -. ARM Cortex-M4: TWR-K60N512 (Freescale) -. ARM7: AT91M55800A (Atmel) -. ARM9: AT91SAM9261-EK (Atmel) -. ARM9: AT91SAM9260-EK (Atmel) -. PC (32bits simulation for GNU/Linux and MS Windows)

Lepton provides more than 150 POSIX functions over a real-time operating system that can be: -. Open source FreeRTOS 9.0. -. Proprietary embOS from Segger. -. Open source eCos community (Deprecated).

Lepton offers the ability to use other real-time operating system (closed or open source) like FreeRTOS by using a simple abstraction layer.

Lepton uses some parts of underlying real-time operating system: -. board startup (HAL) -. basic synchronization functions (semaphore, mutex, ...) -. task sheduler -. ISR mechanisms -. some libraries (math.h, stdlib.h, ...)

In addition Lepton/Tauon offers: -. Unix « philosophy". Everything is file. Everything is a stream of bytes. -. more than 150 functions from POSIX standard (IEEE Std 1003.1a: open(), read(), write(), close(), ioctl(), select() …), BSD Socket… realtime extension (1003.1b) and threads extension (1003.1c) -. simple model for device drivers -. UNIX stream to improve "reuse" -. support lwip stack (2.0) -. support uip stack (3.0 extracted from Contiki project ) -. support rootfs, ufs, fat16 (msdos and vfat), fatfs filesystem -. VFS layer to brings new and custom file systems -. USB devices stack and profils CDC-ACM, MSD and Ethernet-ECM (tested only on AT91SAM9261-EK). Full duplex audio class 1 profile and MSD with stm32f4. -. NanoX and FLTK support (FLNX exactly) -. Mongoose WEB server, FTP server (from trollFTPD) and mini shell -. simulation process under GNU/Linux (Tauon) and Windows (Lepton)

Thanks to:

Philippe Le Boulanger (original author of Lepton and maintainer)

Jean-Jacques Pitrolle (maintainer)


prerequisite scions for lepton operating system construction.



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