Now that WASM_TABLE_SIZE may be capped, we set it slightly below the limit under which chromium crashes: https://bugs.chromium.org/p/v8/issues/detail?id=8427 JIT_THRESHOLD is also reduced due to two reasons: - With the lower WASM_TABLE_SIZE, we want to avoid compiling too many modules - It has occasionally been observed that under node, the engine's wasm compiler can't catch up with the number of modules we produce, thus resulting in 100s of pending compiled modules. This most likely happens only under node as we don't render the screen and the main loop (based on setImmediate) is faster. The new value doesn't seem to exhibit this problem, but we may want to increase the threshold further if the problem appears again |
||
---|---|---|
.cargo | ||
bios | ||
docker | ||
docs | ||
examples | ||
gen | ||
lib | ||
src | ||
tests | ||
tools | ||
.gitignore | ||
.jshint.json | ||
.rustfmt.toml | ||
Cargo.toml | ||
debug.html | ||
index.html | ||
LICENSE | ||
loader.js | ||
Makefile | ||
package.json | ||
Readme.md | ||
v86.css |
Building
See docker/test-image/Dockerfile
for a full setup on Debian.
You need:
- java
- gcc, make, libc-i386
- nasm, gdb and qemu (for running tests)
- rust-nightly with the wasm32-unknown-unknown target
- nodejs (a latest version is required, 10.11.0 is known to be working)
Run make all-debug
to build the debug build (at debug.html
).
Run make all
to build the optimized build (at index.html
).
Testing
Run all tests: make jshint rustfmt kvm-unit-test nasmtests nasmtests-force-jit expect-tests jitpagingtests qemutests rust-test tests
Creating a Linux image for use in v86
See docker/debian-full/Readme.md
.
Below is the readme of the open-source version of v86 (not everything applies)
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.
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 usemake 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
andX
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
- CPU test cases via QEMU, http://wiki.qemu.org/Main_Page
- More tests via kvm-unit-tests
- Disk Images
- The jor1k project for 9p, filesystem and uart drivers
- WinWorld sources of some old operating systems
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
)