Re: [9fans] The details on the kernel panic!

Re: [9fans] The details on the kernel panic!

[Dave Eckhardt]

> This needs a rewrite of the MMU code on the x86, which needs to
> be done for other reasons, but I've had on my list for >5 years.
> It's not going to happen soon.  Sorry.

Are the goals for such a rewrite written down somewhere?  I just
looked in mmu.c and didn't see a todo list there... if there isn't
a "wish list" repository, the source itself might be a good place.

Dave Eckhardt

Re: [9fans] The details on the kernel panic!

[jmk]

On Wed Mar 10 13:13:43 EST 2004, davide+p9@ux1.sp.cs.cmu.edu wrote:
> > This needs a rewrite of the MMU code on the x86, which needs to
> > be done for other reasons, but I've had on my list for >5 years.
> > It's not going to happen soon.  Sorry.
> 
> Are the goals for such a rewrite written down somewhere?  I just
> looked in mmu.c and didn't see a todo list there... if there isn't
> a "wish list" repository, the source itself might be a good place.
> 
> Dave Eckhardt

There is nothing written down in any single public place.

Re: [9fans] The details on the kernel panic!

[Charles Forsyth]

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i did that for a time, and sometimes still do, but i found
it typically caused trouble because no matter how
esoteric the `left to do' list became, some people
concluded ``oh, it's not yet finished'', which was
strictly speaking true (but a bit silly).  i later decided
that if someone was capable of finishing the things
on the `to do' list they were capable of working out
the list themselves once they'd looked at the code;
either that, or the list didn't really matter.

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From: Dave Eckhardt <davide+p9@ux1.sp.cs.cmu.edu>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] The details on the kernel panic!
Date: Wed, 10 Mar 2004 13:11:31 -0500
Message-ID: <25627.1078942291@piper.nectar.cs.cmu.edu>

> This needs a rewrite of the MMU code on the x86, which needs to
> be done for other reasons, but I've had on my list for >5 years.
> It's not going to happen soon.  Sorry.

Are the goals for such a rewrite written down somewhere?  I just
looked in mmu.c and didn't see a todo list there... if there isn't
a "wish list" repository, the source itself might be a good place.

Dave Eckhardt

[9fans] The details on the kernel panic!

[w0rd 2 th3]

Ok, I tried Plan9 on my Thinkpad R31 laptop.. Specs are:
Intel Ethernet card
Intel i810/830M video card
Pentium 3 1.15Ghz (around that much)
512MB Ram
30GB HDD

Now, I tried to choose 'Install Plan9 from this CD' and I got prompted about 
the mouse and video resolution, though before that, I got..
init: starting /bin/rc
echo: write error: bad process or channel control request
Now, after setting it up, both default and when I customized it, I get the 
panic...
panic: mmukmap1: p
panic: mmukmap1: pa 90100000 entry 10000183
I get the same thing when trying to boot from CD rather than install though 
/bin/rc started properly..
Can anyone tell me what I'm doing wrong or how to fix this?
I hope someone can help..
Thanks alot.

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Re: [9fans] The details on the kernel panic!

[gdiaz]

Hello,

you can try to install p9 with vmware demo version (downloadable from 
www.vmare.com) from other OS. Give vmware access to real disk on your thinkpad 
and install plan9 on it. 
Then you can try to compile your kernel with your requirements.
 
If you have another computer you can modify plan9.ini to send kernel events to 
serial ports, that would help you to write all debug messages produced by 
kernel on panic.

In step by step way you can do:

1. download and install vmware demo (valid for 30days i think)
2. install plan9 on you real harddisk in a p9 partition using last compiled CD 
and vmware
3. modify plan9.ini (booted from vmware)to send events to serial
4. connect your serial to another computer
5. boot your laptop and save error messages recorded from serial port
6. modify your kernel as needed (hehehehe)
7. compile it from vmware
8. add a boot menu to plan9.ini , and test the new kernel you just compiled
9. report your experiences here or to 9trouble mail list

BTW,I tested P9 with i815 video card and it worked fine (on VAIO PCG-FX)

I hope that you have luck

gabi.

Quoting w0rd 2 th3 <zbxhfhxha@hotmail.com>:

> Ok, I tried Plan9 on my Thinkpad R31 laptop.. Specs are:
> Intel Ethernet card
> Intel i810/830M video card
> Pentium 3 1.15Ghz (around that much)
> 512MB Ram
> 30GB HDD
> 
> Now, I tried to choose 'Install Plan9 from this CD' and I got prompted about
> 
> the mouse and video resolution, though before that, I got..
> init: starting /bin/rc
> echo: write error: bad process or channel control request
> Now, after setting it up, both default and when I customized it, I get the 
> panic...
> panic: mmukmap1: p
> panic: mmukmap1: pa 90100000 entry 10000183
> I get the same thing when trying to boot from CD rather than install though 
> /bin/rc started properly..
> Can anyone tell me what I'm doing wrong or how to fix this?
> I hope someone can help..
> Thanks alot.
> 
> _________________________________________________________________
> Add photos to your e-mail with MSN 8. Get 2 months FREE*. 
> http://join.msn.com/?page=features/featuredemail
> 
> 

Re: [9fans] The details on the kernel panic!

[jmk]

You would find the answer to this if you looked back far enough in the
archives. The BIOS has placed the framebuffer physical address at a place
where, when converted to a virtual address by the kernel using a one-to-one
mapping stating at 0x80000000, it clashes with allocated physical memory.
E.g.
	physical memory goes from 0 to 0x20000000 (512MB);
	kernel maps this to virtual by or'ing with 0x80000000, thus kernel
		virtual memory goes from 0x80000000 to 0xA0000000;
	the framebuffer physical address is 0x90100000;
	the kernel tries to map that to a virtual address
		(0x80000000|0x90100000 == 0x90100000) and finds it already has
		a mapping for that virtual address;
	boom.

Sometimes, depending on the model of graphics chip, you can bypass this by
deleting the 'linear=1' option in the vgadb entry for the controller, but
I don't think that's possible with this controller.

It's possible the base address of the framebuffer could be changed with this
chip, but I'm not familiar with it and don't have one to try.

This needs a rewrite of the MMU code on the x86, which needs to be done for
other reasons, but I've had on my list for >5 years. It's not going to happen
soon. Sorry.

--jim


On Wed Mar 10 10:50:51 EST 2004, zbxhfhxha@hotmail.com wrote:
> Ok, I tried Plan9 on my Thinkpad R31 laptop.. Specs are:
> Intel Ethernet card
> Intel i810/830M video card
> Pentium 3 1.15Ghz (around that much)
> 512MB Ram
> 30GB HDD
> 
> Now, I tried to choose 'Install Plan9 from this CD' and I got prompted about 
> the mouse and video resolution, though before that, I got..
> init: starting /bin/rc
> echo: write error: bad process or channel control request
> Now, after setting it up, both default and when I customized it, I get the 
> panic...
> panic: mmukmap1: p
> panic: mmukmap1: pa 90100000 entry 10000183
> I get the same thing when trying to boot from CD rather than install though 
> /bin/rc started properly..
> Can anyone tell me what I'm doing wrong or how to fix this?
> I hope someone can help..
> Thanks alot.
> 
> _________________________________________________________________
> Add photos to your e-mail with MSN 8. Get 2 months FREE*. 
> http://join.msn.com/?page=features/featuredemail