BeRTOS
|
If you are looking for the list of BeRTOS ports or a detailed overview of all modules completeness and stability this is the right place.
BeRTOS is stable and it's used in production environments but it is also a very large project, so all of its parts may not be at the same level.
Table of contents:
BeRTOS features a cooperative kernel with synchronization primitives.
Embedded systems are mostly I/O bound systems. In these systems the microprocessor/microcontroller spends the most part of its computing power doing... absolutely nothing :-)
Since the system simply waits for external events to happen we decided to implement a strong and robust cooperative kernel with very low memory footprint and high modularity. This allows the kernel to be used on a variety of different CPUs, even the smaller ones. Currently the kernel code is very stable.
Kernel features :
The kernel has a port layer (a single assembly function) that needs to be reimplemented each time a new CPU is added. Here is a list of currently available CPU family ports:
CPU Family | Port status |
ARM7TDMI | Atmel AT91SAM7, NXP LPC2XXX |
Cortex-M3 | Luminary Stellaris LM3S, ST Microelectronics STM32 |
Atmel AVR | Most cpu supported (including Arduino) |
PowerPC | emulator |
Intel/AMD x86 | emulator |
Intel/AMD x86-64 | emulator |
BeRTOS is not only a kernel, it aims to supply full operating system services. To achieve this we need at least some core drivers for every CPU port.
These drivers are: system timer , debug system and serial comm driver .
Adding CPU support for an already present CPU family is quite simple since hardware manufacturers share peripherals design between the same CPU cores.
Core drivers are completely supported on all platforms.
Since BeRTOS aims to supply full operating system services, for every CPU port we try to implement as much drivers as possible. This section covers the current development status for MCU Internal peripheral drivers.
Driver / MCU family | ADC | UART | FLASH | I2C | PWM | SPI |
Atmel AVR | Yes | Yes | Yes | Yes | Yes | Yes |
Atmel AT91SAM7 ARM | Yes | Yes | Yes | Yes | Yes | Yes |
Atmel AT91SAM3N ARM | - | Yes | - | - | - | - |
STmicro STM32F103xx ARM | Yes | Yes | Yes | Yes | - | - |
Philips LPC23XX ARM | - | Yes | Yes | Yes | - | - |
Stellaris LM3S ARM | Yes | Yes | Yes | Yes | - | Yes |
BeRTOS supplies a full set of CPU independent generic hardware drivers. To achieve this all drivers are structured to have an hardware abstraction layer (HAL) that isolate CPU specific code and makes porting to new CPU easy. Current driver list:
Driver | Status |
ADC API | stable |
Buzzer | stable |
Atmel Dataflash | stable |
I2C EEPROM | stable |
AT25Fxxx Atmel flash memories | beta |
FT245RL USB to parallel converter | beta |
Keyboard | stable |
I2C with bitbang support | stable |
Displaytech 32122A Graphic LCD | stable |
DC Motor with PID | stable |
Alphanumeric LCD | stable |
LM75 temperature sensor | stable |
MPC41 digital potentiometer | stable |
MPxx6115A pressure sensor | stable |
NTC | stable |
TRIAC phase partialization | stable |
PWM API | beta |
PCF85974 I2C port expander | beta |
Secure Digital card API | stable |
Serial API | stable |
Bitbanged SPI | stable |
TAS5706A digital audio DSP | stable |
TC520 ADC | obsolete |
Thermostat | stable |
System timer API | stable |
TMP123 temperature sensor | stable |
Stepper motor with ramps | stable |
Watchdog | beta |
To get up to date informations look at the drivers source code.
BeRTOS supports two file systems. The first one is the mainstream FAT filesystem, using the FatFs library. The module is highly configurable, for example it can be compiled in read-only mode for some space saving.
The second is BattFs, a file system specifically planned for embedded platforms. The goal is to have a filesystem suitable for little flash and eeprom memories (like dataflash), reliable, robust and capable of wear-levelling the memory pages to increase its life. The code is in beta stage. Currently you can create files, append data to them but file deletion is still not supported. Wear-levelling is achieved by rotating a page every time it is written. Plans are to add even transactions (a whole write can be performed atomically).
File system development takes place in the fs directory.
The FAT file system is the de-facto standard for removable devices such as SD cards or Memory cards. BeRTOS supports read and write operations on all existing FAT file systems, ranging from FAT12 to FAT32, with support to long file names. This file system is light and fast and allows to easily exchange data through external memory devices.
FAT module is highly configurable, for example it can be compiled in read-only mode for some space saving.
BattFS (Batt File System), has been developed to solve problems specific to embedded systems; BattFS is a file system that can be used on any physical media and it's optimized to reduce RAM and ROM usage to meet the strict design guidelines we have used with all the others BeRTOS components.
The goal is to have a filesystem suitable for little flash and eeprom memories (like dataflash), reliable, robust and capable of wear-levelling the memory pages to increase its life.
The code is in beta stage. Currently you can create files, append data to them but file deletion is still not supported. Wear-levelling is achieved by rotating a page every time it is written. Plans are to add even transactions (a whole write can be performed atomically).
BeRTOS also features a complete graphic subsystem, suitable for generating compact yet powerful GUI. This system is composed of several modules ranging from simple graphic primitives to complex menu management functions.
Module | Status |
Bitmaps manipulation | stable |
Lines drawing | stable |
Rectangles drawing | stable |
Simple windowing system | stable |
Proportional and fixed size fonts | stable |
Text rendering | stable |
Simple Charts | stable |
Menus | stable |
To get up to date informations look at the source code in the directories gfx, gui or fonts.
In embedded programming sometimes you have to cope with protocols, security systems and things like that. BeRTOS comes in help with a set of optimized portable algorithms:
Algorithm | Status |
CRC16 | stable |
MD2 | beta |
Cryptographically secure Random Pool | beta |
Rotating hash checksum | stable |
TEA (Tiny Encryption Algorithm) | stable |
Stepper motor ramp generator | stable |
PID Controller | stable |
RLE (Run lenght en/decondig) | stable |
To get up to date informations look at the algorithms source code.
Since BeRTOS can also be used in very tiny systems, some simple communication protocols has been developed.
This is the current status:
Protocol | Status |
PocketBus | stable |
Keytag (for 125KHz transponders) | stable |
XModem protocol | stable |
NMEA GPS protocol parser | stable |
AFSK1200 modem | stable |
AX25 data link layer protocol | beta |
For more information take a look at network directory.
BeRTOS supplies common data structures, implemented and optimized for low memory footprint and speed.
Module | Status |
FIFO | stable |
Hash table | stable |
Embedded-optimized dynamic memory allocator | stable |
Lists | stable |
This section covers all BeRTOS modules that provide general purpose utility functions. Most of them should be moved to Algorithms directory.
In the meanwhile, here is the list:
Module | Status |
Integers to/from host byte-order conversion | stable |
Events | stable |
C++ like exception handling in C | stable |
Embedded-optimized printf | stable |
Command shell with history | stable |
Ini file reader | stable |
As usual, check source code for detailed reference.