dummyOS

dummyOS is a hobby UNIX-like operating system written in C and assembly. It runs on x86 and armv7 (Raspberry Pi 2).

The system provides a basic list of system calls and a port of the newlib C library for easy userspace programmming.

https://github.com/CheezeCake/dummyOS

Kernel

• 31 system calls
• POSIX signals
• CoW fork()

x86

• VGA console
• Keyboard

Raspberry Pi 2 (BCM2836)

• Serial console (UART0 or UART1)
• GPIO driver

System calls

• exit
• fork
• getpid
• getppid
• signal
• sigaction
• sigreturn
• kill
• wait
• waitpid
• execve
• open
• close
• lseek
• read
• write
• setsid
• setpgid
• getpgid
• setpgrp
• getpgrp
• ioctl
• sbrk
• getdents
• sigprocmask
• pipe
• dup
• dup2
• stat
• fstat
• nanosleep

Userspace

• Simple shell with pipe support
• Some standard Unix utilities from NetBSD or OpenBSD

C library

Full port of the newlib C library (https://github.com/CheezeCake/newlib-dummyOS)