Bitflow

A hobby 32-bit x86 kernel written in C and assembly.

Features

• Protected mode with ring 0/3 separation
• Preemptive multitasking with round-robin scheduling
• Keyboard input via PS/2 interrupt handler
• ATA disk driver for loading tasks at runtime
• Simple shell with command execution
• VGA text mode console

Tutorial

A step-by-step guide to building this kernel from scratch is available in the tutorial folder.

Building

Requires an i686-elf cross-compiler toolchain (GCC, LD) and NASM.

make

Running

make run # curses mode (in terminal)
make run-window # graphical window

Disk Layout

Sector 0 Boot sector
Sector 1 File table (generated at build time)
Sector 2+ Kernel
... Tasks, fonts

The file table maps task names to their disk sectors, so the loader can find them at runtime without hardcoded offsets.

Shell Commands

• help - list commands
• about - version info
• tasks - show running tasks
• task_a, task_b - load sample tasks from disk
• quit - shutdown

License

MIT