[9fans] snapshot fails to boot

[9fans] snapshot fails to boot

[David Hoskin]

I tried installing a recent snapshot on my laptop (Acer Travelmate
2450 , from late 2006), which failed with the following message from
the bootloader:

Press almost any key to reset... FLAGS=10202 TRAP=6 ECODE=0 PC=3
AX 800116e1 BX 00000f3e CX 8006407 DX 000003d5
SI 800b8fa0 DI 800b8fa0 BP 0000002e
CS 0010 DS 0008 ES 0008 FS 0008 GS 0008
CR0 80000011 CR2 00000000 CR3 0000c000
panic: exception/interrupt 6

(retyped by hand)  there were several pages of these; this was the last message.
This message was the same between the floppy and the cd.

This occured both from a floppy image (usb floppy drive) and a cd.
I tried downloading and burning the cd twice to make sure it wasn't corruption.

The cd images were from the end of July, and the floppy was from early August.

They both boot fine under QEMU.


I tried a cd from 2008, and it booted and installed fine on this laptop.

Is there any other information on my setup, etc that would be useful?


Thanks,
--
David Hoskin < root@davidrhoskin.com >

Re: [9fans] snapshot fails to boot

[erik quanstrom]

> Press almost any key to reset... FLAGS=10202 TRAP=6 ECODE=0 PC=3
> AX 800116e1 BX 00000f3e CX 8006407 DX 000003d5
> SI 800b8fa0 DI 800b8fa0 BP 0000002e
> CS 0010 DS 0008 ES 0008 FS 0008 GS 0008
> CR0 80000011 CR2 00000000 CR3 0000c000
> panic: exception/interrupt 6

very difficult to say anything useful, since the pc is
nonsense and the error is "invalid opcode".  is
anything printed before the fatail error?

- erik

Re: [9fans] snapshot fails to boot

[David Hoskin]

> Is anything printed before the fatal error?

It printed PBS1... , then dumped 2-3 pages of messages too quickly for
me to read.

The message above the one I quoted was the same, except FLAGS=10206 instead.

After this message, it tried to print another in the same format, but
all numbers were replaced with %u% .

If I can figure out how to build the new bootloader from my 2008
install, I can have a try at seeing where it fails - any pointers to
get started / where to try first?

Thanks,
--
David Hoskin < root@davidrhoskin.com >

Re: [9fans] snapshot fails to boot

[David Hoskin]

> If I can figure out how to build the new bootloader from my 2008
> install, I can have a try at seeing where it fails - any pointers to
> get started / where to try first?


update:  The new cd does boot on another computer, so I can use it for
compiling, rather than working from the 2008 system.

Re: [9fans] snapshot fails to boot

[erik quanstrom]

> It printed PBS1... , then dumped 2-3 pages of messages too quickly for
> me to read.
>
> The message above the one I quoted was the same, except FLAGS=10206 instead.
>
> After this message, it tried to print another in the same format, but
> all numbers were replaced with %u% .
>
> If I can figure out how to build the new bootloader from my 2008
> install, I can have a try at seeing where it fails - any pointers to
> get started / where to try first?

you might try 9atom, which has a slightly different loader.
ftp://ftp.quanstro.net/other/9atom.iso.bz2
you can also just use the loader by itself,
ftp://ftp.quanstro.net/other/9load-e820.mkfs.bz2
(bunzip2 < 9load-e820.mkfs.bz2 | {mkdir 9load-e820 ; mkext -d 9load-e820})

otherwise, i have two tricks for dealing with crashes that
scroll by.

1.  set up a serial console.  force the serial console on
in load.c and hope you get that far.  here's where i put
consinit when i'm doing that sort of debugging:

void
main(void)
{
	Medium *mp;
	int flag, i, mode, tried;
	char def[2*NAMELEN], line[80], *p, *file;
	Type *tp;

	i8042a20();
	memset(m, 0, sizeof(Mach));
//consinit("0", 0);


2. if you don't get as far as consinit() or don't have the equipment
to set up a serial connection, you can take a movie with a digital
camera and then slow-mo through it.  it was a trick that i first used
a few weeks ago when i had a blade machine crashing.  it didn't have
a serial console that i knew how to configure at the time.

the trick seems self-evident now but took a while to think up.  :-)

- erik

Re: [9fans] snapshot fails to boot

[David Hoskin]

Hi Erik,

I tried booting 9atom; it failed with the same error, then printed
random garbage across the screen.

I'll try poking around with it to see where it crashes once I have an
install to build from on my other computer.

If I take the 2008 bootloader, can it boot a modern kernel?

Thanks,
--
David Hoskin < root@davidrhoskin.com >

Re: [9fans] snapshot fails to boot

[erik quanstrom]

> I tried booting 9atom; it failed with the same error, then printed
> random garbage across the screen.
>
> I'll try poking around with it to see where it crashes once I have an
> install to build from on my other computer.
>
> I'll try poking around with it to see where it crashes once I have an
> install to build from on my other computer.

any information you could get would be great.  does it happen
to print out a pc or other identifiable info?

> If I take the 2008 bootloader, can it boot a modern kernel?

yes.

- erik