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src.rivoreo.one / emulators / v86 / 818a6c211fab73b85b287fef910e6efb8d75ec1c
commit818a6c211fab73b85b287fef910e6efb8d75ec1c[log] [download]
authorErnest Wong <ewon521@gmail.com>Wed Nov 15 08:57:03 2017 +1300
committerFabian <copy@copy.sh>Sat Dec 16 22:51:40 2017 -0600
tree08579946e8553400456551f7428ddaf740c3b961
parent5c0e87b3e96b58eeb790a96053f860260f3e1ad0 [diff]
Wrap PIT counter value - always

After restore_state, the pit.counter_start_time can be larger
than the current timestamp, leading to negative diff values, and
as a result, when get_counter_value is called, it can return
values larger than 16 bit integers. Thus, when ISA ports 0x40, 0x41, or
0x42 are read, the high-byte that counter_write returns can be larger
than 8-bit. Ultimately, this error is caught by the asserts in io.js. By
always applying a positive modulo to the counter value, it is always
ensured that the counter value is between zero and the reload value.
1 file changed
tree: 08579946e8553400456551f7428ddaf740c3b961
  1. .gitignore
  2. .travis-run-integration.sh
  3. .travis-run-nasm.sh
  4. .travis-run-unit-qemu.sh
  5. .travis-run-unit.sh
  6. .travis.yml
  7. LICENSE
  8. Makefile
  9. Readme.md
  10. bios/
  11. debug.html
  12. docs/
  13. examples/
  14. index.html
  15. lib/
  16. loader.js
  17. package.json
  18. src/
  19. tests/
  20. v86.css
Readme.md

Join the chat at https://gitter.im/copy/v86

Demos

API examples

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.

Testing

The disk images are not included in this repository. You can download them directly from the website using:

wget -P images/ https://copy.sh/v86/images/{linux.iso,linux3.iso,kolibri.img,windows101.img,os8.dsk,freedos722.img,openbsd.img}.

A testsuite is available in tests/full/. Run it using node tests/full/run.js.

How to build, run and embed?

  • Building is only necessary for releases, open debug.html and everything should load out of the box
  • 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 only want to embed v86 in a webpage 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/ https://copy.sh/v86/images/{linux.iso,linux3.iso,kolibri.img,windows101.img,os8.dsk,freedos722.img,openbsd.img}.

Short summary:

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

# grab the disk images
wget -P images/ https://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 https://dl.google.com/closure-compiler/compiler-latest.zip
unzip -d closure-compiler closure-compiler/compiler-latest.zip *.jar

# build the library
make build/libv86.js

# run the tests
./tests/full/run.js

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): Works, takes circa 10 minutes to boot.
    • Tinycore (3.0 kernel): udev and X fail, but you get a terminal.
    • Nanolinux works.
    • Archlinux works with some caveats. See archlinux.md.
  • ReactOS works
  • FreeDOS, Windows 1.01 and MS-DOS run very well.
  • KolibriOS works. A few applications need SSE.
  • Haiku boots, but takes very long (around 30 minutes).
  • No Android version seems to work, you still get a shell.
  • Windows 1, 95 and 98 work. Other versions currently don't.
  • Many hobby operating systems work.
  • FreeBSD works

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

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)