GTMOS

A hobby operating system based of duckOS

A hobby UNIX-like OS with a graphical window manager for x86 computers.

What's working

• Booting off of the primary master IDE (PATA) hard drive on both emulators and real hardware (tested on a Dell Optiplex 320 with a Pentium D)
• PATA DMA or PIO access (force PIO by using the use_pio grub kernel argument)
• A virtual filesystem with device files (/dev/hda, /dev/zero, /dev/random, /dev/fb, /dev/tty, etc)
  • The root filesystem is ext2, and is writeable
• Disk caching
• Dynamic linking with shared libraries
• A Bochs/Qemu/VirtualBox/Multiboot video driver (640x480x32bpp)
• A window manager / compositor called pond
• Various GUI applications
• More!

Services

The code for these can be found in services.

• init (/bin/init): The init system for duckOS.
• pond (/bin/pond): The (very-WIP) window manager / compositor for duckOS.

GUI Programs

The code for these can be found in programs

• Calculator (/apps/calculator.app): A basic calculator.
• Terminal (/apps/terminal.app): A libui-based terminal application.
• System Monitor (/apps/monitor.app): A basic system monitor showing memory and CPU utilization.
• 4 In a Row (/apps/4inarow.app): A basic four-in-a-row game. Play with two players or against the computer.
• Sandbar (/bin/sandbar): A basic "taskbar" that displays a row of buttons at the bottom of the screen to launch applications.
• Files (/apps/files.app): A rudimentary file explorer application.

CLI Programs

The code for these can be found in programs.

• ls (/bin/ls): Lists the entries in the current or given directory.
• cat (/bin/cat): Writes the contents of a file to stdout.
• cp (/bin/cp): Copies a file.
• mv (/bin/mv): Moves a file.
• pwd (/bin/pwd): Prints the current working directory.
• mkdir (/bin/mkdir): Creates a new directory.
• echo (/bin/echo): Prints the arguments given to it separated by spaces to stdout.
• rm (/bin/rm): Removes a file.
• ln (/bin/ln): Creates a hard or symbolic link to a file or directory.
• rmdir (/bin/rmdir): Removes a directory.
• touch (/bin/touch): Updates the access/modification times of a file or creates it if it doesn't exist.
• truncate (/bin/truncate): Resizes a file.
• chmod (/bin/chmod): Changes the mode of a file.
• chown (/bin/chown): Changes the owner of a file.
• free (/bin/free): Shows the amount of total, used, and free memory (use the -h flag for human-readable numbers).
• ps (/bin/ps): Shows the currently running processes.
• dsh (/bin/dsh): A basic userspace shell with support for pipes (|) and redirections (>/>>).
  • There is only support for one redirection at a time right now.
• apprun (/bin/apprun): A utility to run applications from the command line.

Programs that take arguments will provide you with the correct usage when you run them without arguments.

Libraries

• libc: The standard C library.
• libm: The math portion of the standard C library.
• libpond: The library used for interfacing with the pond window manager / compositor.
• libgraphics: A library which provides a few utilities for working with graphics such as image format loading.
• libui: A UI framework for applications.
• libterm: A framework for handling terminals.
• libduck: A library containing commonly used classes and utilities, such as argument and configuration file parsing.
• libriver: An IPC library not dissimilar to D-Bus, which provides a framework for remote function calls and data passing.
• libapp: A library providing methods to retrieve information about installed and running applications.
• libsys: Provides higher-level C++ abstractions for retrieving system information, namely from procFS.

Ports

Ports will only compile if their corresponding submodule is downloaded with git submodule init and git submodule update.

• DOOM: A little buggy at the moment, but playable. With the current multitasking and window manager implementation, it can be a little slow.

Known Issues / Limitations

• Framebuffer scrolling is slow on real hardware. I'm not focusing on fixing this right now until I start working on a window manager.
• Must be booted off of the master drive on the primary PATA controller as of now.
• Ext2 triply indirect block pointers cannot be read/written, so there may be issues writing and reading large files
• A buffer overflow attack on the kernel may be possible, because only pointers passed to syscalls are checked for validity (and not the length of the data to be read/written)
• Dynamic linking does not currently use CoW to share memory between processes, so each process has its own copy of the library in memory
• It's pretty unstable

Future Goals

• Cut down on memory usage by sharing memory for various commonly used items (libraries, icons, configuration, etc)
• Better support for real hardware
• Network support
• Sound support
• More s t a b i l i t y and s p e e d
• Multiprocessor (multicore) support
• An in-house heap implementation
• More POSIX compatibility
• Better looking UI with animations and effects such as shadows and blur/transparency
• Slowly transition various functions from the kernel to userspace (ie microkernel)
• A better filesystem cache implementation that can free memory when needed and periodically flushes writes

Building / Running

• See INSTRUCTIONS.md for instructions.

Credits

• blanham's mirror of liballoc 1.1 for the kernel heap allocation implementation (it's open domain, so if you want to use it, I highly recommend it)
• SRombaut's implementation of shared_ptr
• SerenityOS for a lot of inspiration
• Gohufont for the font (licensed under WTFPL)

License

• See LICENSE.TXT.