Boot Windows XP

[Creeper20428]

Windows XP and OS/2 don't boot because of an unhandled double fault exception.

At the page fault handler, I tried doing this:

if(this.page_fault)
    {
        dbg_trace(LOG_CPU);
        //throw this.debug.unimpl("Double fault");
        this.interrupt(6, false, false); // I also fiddled around with these:
/*
this.interrupt(6, false, true);
this.interrupt(6, true, true);
this.interrupt(6, true, false);
*/
    }

but then there were more #GP exceptions and it would have triple-faulted anyways.

It would be really cool to see Windows or OS/2 booting.

[copy]

Windows XP and OS/2 don't boot because of an unhandled double fault exception.

It's not the double fault exception that causes this. The double fault shouldn't happen in the first place. If you want to see how far Windows XP gets, set ENABLE_ACPI to true here. It's experimental and will cause some other OSes to stop working. After that Windows XP gets stuck on a black screen. The APIC needs some more work.

What version of OS/2 are you testing? If possible, can you upload a disk image?

I have managed to get Windows NT 4.0 to start properly in copy.sh if you want to see a Windows NT-based operating system working in it, you can use NT 4.0. Just letting you know!

That's very cool, I'm also testing a (probably different) version of Windows NT and it doesn't work for me. Did you apply some fixes? Can you upload a disk image somewhere?

[Creeper20428]

I'm guessing that the ACPI interpreter is failing (it's very strict, according to what I heard).
According to osdev.org, the ACPI tables seem to be very complex.
Couldn't we just copy the tables from an emulator like Bochs and insert it into the memory? Something like this:
if(ENABLE_ACPI){ cpu.memory.u8.set([ 1, 2, 3, 4, cpu.something | someValue, ...], 0x1234567]); }
These are tables, after all. How hard could it be to copy tables?

BTW I am using OS/2 Warp 4.52 (I think). I created the disk image in QEMU and I'll try to upload it somewhere. There used to be a 16-bit iret problem but now it's gone, thanks to a recent commit. :)

[Creeper20428]

I think I figured out why some OSes don't work when ACPI is enabled. It's not the emulator's fault (although it might be -- you never know). Early OSes have no support for ACPI at all (see https://en.wikipedia.org/wiki/Advanced_Configuration_and_Power_Interface#Operating_systems). When an OS, such as DOS sees random AML bytecode in spots where x86 code is supposed to be, then things go south....

[copy]

These are tables, after all. How hard could it be to copy tables?

This isn't necessary, the bios sets up ACPI tables: https://github.com/KevinOConnor/seabios/blob/master/src/fw/acpi.c

Early OSes have no support for ACPI at all

That's good to know, this will need to be a runtime option then.

[Creeper20428]

Then what's the problem? Is there an I/O port that's mis-reading/writing?

And BTW, how do you debug things like this?

[copy]

Then what's the problem? Is there an I/O port that's mis-reading/writing?

The APIC implementation is quite incomplete, so there are just many parts missing (or wrong).

And BTW, how do you debug things like this?

Run the emulator in debug.html. You'll see a rather verbose log in the JavaScript console, XP produces this: https://gist.github.com/copy/c4de5225317922d035d3

You can see what is being used. There are some unimplemented IO ports. Then Windows goes to sleep waiting for something to happen, probably an interrupt. Could also be related to that RTC register.

[Creeper20428]

Is it ACPI or APIC?

In the code, I saw "APIC" in acpi.js.

[copy]

Is it ACPI or APIC?

ACPI needs to be enabled for it to work at all. APIC implementation is incomplete.

In the code, I saw "APIC" in acpi.js.

Do you have the latest version?

[Creeper20428]

I have one from a while ago -- it still has traces of the dynamic translator in it.

So, let me get these things straight:
Windows XP doesn't boot because of incomplete ACPI ports and an incomplete APIC implementation.
OS/2 Warp 4.52 doesn't boot because of... I don't know. I'm uploading to Dropbox right now.

[Creeper20428]

https://www.dropbox.com/s/k970phbvyk6erdy/os2.img.vmdk?dl=0

That's the file (I made it in QEMU)

[copy]

Thanks for the disk image. After a bit of fixing small things, I found that OS/2 uses far call gates, which aren't implemented yet.

Windows XP doesn't boot because of incomplete ACPI ports and an incomplete APIC implementation.

Probably the latter, yes.

[Creeper20428]

So Win XP doesn't boot because of APIC problems and OS/2 doesn't boot because of far call gates.

[Creeper20428]

Sounds fun!

[Creeper20428]

I did some research yesterday and I discovered this:
http://lifehacker.com/5827222/jpc-2-lets-your-run-windows-xp-and-ubuntu-in-your-web-browser

I just thought it was interesting.
Unfortunately, it's not up anymore :(