elix is a hobby-grade "operating system"-sh thing designed to be portable and explore various ideas out of curiousity. It is not intended to be used in production of any sort.
elix initially started as MiSPOS, a relatively high-level "framework" with hardware drivers, intended for the rapid development of MSP430 software. elix has deviated from this quite a bit, and now has the following aims:
- Cross-platform source compatibility for software written to run under elix.
- Ability to be ported (relatively) easily to new platforms.
- A layer of "drivers" that sit between the common elix core and hardware.
- For these reasons, a core written in entirely in C.
The elix virtual machine is stack-based, and provides a limited number of opcodes. These can be executed continuously in a cross-platform, multitasking environment. The opcodes are continually streamed from the disk layer.
This approach provides the following benefits, pursuant to elix's purpose:
- Flexibility: Streaming from disk allows functioning in extremely RAM-limited environments.
- Portability: This approach can be binary-compatible, as well as source-compatible.
- Security: With proper setup, the VM can isolate tasks from each other.
- Multitasking: This avoids setjmp/longjmp, for which extremely low-resource environments lack available memory.
the primary drawbacks at the moment are:
- Code Size: The opcodes take up space in the core.
- Speed: Streaming from the disk severely limits performance.
- Hardware: Low-resource environments may require hardware they would not ordinarily need (extra RAM, a disk interface).
This project uses cmake to generate its build files.
MSP430:
mkdir build && cd build && cmake -DCMAKE_TOOLCHAIN_FILE=path-to-msp430-gcc/generic-msp430-gcc.cmake -DMSP430_MCU=msp430g2553 ..
Code inspector static analysis results available at: https://www.code-inspector.com/project/dashboard/579
Current documentation is available at: https://indigoparadox.github.io/elix/
| Definition | Type | Notes |
|---|---|---|
| QD_CONSOLE_IN | String | Device to input from (uart/keyboard) |
| QD_CONSOLE_OUT | String | Device to output on (uart/display) |
| QD_SPI | On/Off | SPI enabled (where supported) |
| QD_CPU_MHZ | Integer | CPU clock speed (where supported) |
| QD_UART_SW | On/Off | Enable software UART |
| QD_UART_HW | On/Off | Enable hardware UART |
While this project is intended to be cross-platform, there will be differences between platfornms. Those differences should be noted here.
Serial ports may be enabled or disabled, but if they are enabled, then certain ports will always have the same ID.
| UART Index | Type | Pins |------------|----------| | 0 | Software | | 1 | Hardware | | 2 | Hardware | | 3 | N/A |