Demos

• Linux
• Linux 3
• KolibriOS
• FreeDOS
• Windows 1.01
• Archlinux (possibly unstable)

API examples

• Basic
• Programatically using the serial terminal
• A LUA interpreter
• Two instances in one window
• Saving and restoring emulator state

Using v86 for your own purposes is as easy as:

var emulator = new V86Starter({
    screen_container: document.getElementById("screen_container"),
    bios: {
        url: "../../bios/seabios.bin",
    },
    vga_bios: {
        url: "../../bios/vgabios.bin",
    },
    cdrom: {
        url: "../../images/linux.iso",
    },
    autostart: true,
});

See API.

How does it work?

v86 emulates an x86-compatible CPU and hardware. Here's a list of emulated hardware:

• An x86 compatible CPU. The instruction set is around Pentium 1 level. Some features are missing, more specifically:
  • Task gates, far calls in protected mode
  • 16 bit protected mode features
  • Single stepping
  • MMX, SSE
  • A bunch of FPU instructions
  • Some exceptions
• A floating point unit (FPU). Calculations are done with JavaScript's double precision numbers (64 bit), so they are not as precise as calculations on a real FPU (80 bit).
• A floppy disk controller (8272A).
• An 8042 Keyboard Controller, PS2. With mouse support.
• An 8254 Programmable Interval Timer (PIT).
• An 8259 Programmable Interrupt Controller (PIC).
• A CMOS Real Time Clock (RTC).
• A VGA controller with SVGA support and Bochs VBE Extensions.
• A PCI bus. This one is partly incomplete and not used by every device.
• An IDE disk controller.
• An NE2000 (8390) PCI network card.
• A virtio filesystem.

How to build, run and embed?

• In order to build the cpu.js file, you need make and cpp (the C preprocessor). Run: make build/cpu.js.
• If you want a compressed and fast (i.e. with debug code removed) version, you need Closure Compiler. Download it as shown below and run make build/v86_all.js.
• ROM and disk images are loaded via XHR, so if you want to try out index.html locally, make sure to serve it from a local webserver. You can use make run to serve the files using Python's SimpleHTTPServer.
• If you want only want to embed v86 on website you can use libv86.js. For usage, check out the API and examples.
• A couple of disk images are provided for testing. You can check them out using wget -P images/ http://copy.sh/v86/images/{linux.iso,linux3.iso,kolibri.img,windows101.img,os8.dsk,freedos722.img,openbsd.img}.

Summary:

# grab the main repo
git clone https://github.com/copy/v86.git

cd v86

# grab the disk images
wget -P images/ http://copy.sh/v86/images/{linux.iso,linux3.iso,kolibri.img,windows101.img,os8.dsk,freedos722.img,openbsd.img}

# grab closure compiler
wget -P closure-compiler http://dl.google.com/closure-compiler/compiler-latest.zip
unzip -d closure-compiler closure-compiler/compiler-latest.zip compiler.jar

Rebuild compiled version:

make

Rebuild only debug version (only necessary after changing .macro.js files):

make build/cpu.js

Why?

Similiar projects have been done before, but I decided to work on this as a fun project and learn something about the x86 architecture. It has grown pretty advanced and I got Linux and KolibriOS working, so there might be some actual uses.

If you build something interesting, let me know.

Compatibility

Here's an overview of the operating systems supported in v86:

• Linux works pretty well. Graphical boot fails in many versions, but you mostly get a shell. The mouse is often not detected automatically.
  • Damn Small Linux (2.4 Kernel): Run with lowram and choose PS2 mouse in xsetup. Takes circa 10 minutes to boot.
  • Tinycore (3.0 kernel): udev and X fail, but you get a terminal.
  • Nanolinux works.
  • Archlinux works. Add atkbd to MODULES in /etc/mkinitcpio.conf.
• FreeDOS and Windows 1.01 run very well.
• KolibriOS works. A few applications need SSE.
• Haiku boots, but takes very long (around 30 minutes). Set the memory size to 128MB.
• ReactOS doesn't work.
• No Android version seems to work, you still get a shell.

You can get some infos on the disk images here: https://github.com/copy/images.

How can I contribute?

• Add new features (hardware devices, fill holes in the CPU), fix bugs. Check out the issues section and contact me if you need help.
• Report bugs.
• If you want to donate, let me know.

License

Simplified BSD License, see LICENSE, unless otherwise noted.

Credits

• Test cases via QEMU, http://wiki.qemu.org/Main_Page
• Disk Images
• The jor1k project for 9p and filesystem drivers

More questions?

Shoot me an email to copy@copy.sh. Please don't tell about bugs via mail, create a bug report on GitHub instead.

Author

Fabian Hemmer (http://copy.sh/, copy@copy.sh)