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From: qwx <qwx@sciops.net>
To: 9front@9front.org
Subject: Re: [9front] trident cyber 9525 graphics glitches
Date: Mon, 06 Sep 2021 00:52:37 +0200	[thread overview]
Message-ID: <C60B2B7426E5DBDAA014F48E2F4DB362@wopr.sciops.net> (raw)
In-Reply-To: <1630860700604.2131728698.1474874245@vivaldi.net>

Hi lyndsay,

> first of all, the vanilla /lib/vgadb does not have an entry with the right 
> BIOS identifier for this device, so it wasn't giving me any graphical 
> output regardless of the settings i chose at first. i was able to revise 
> the cyber938x entry in /lib/vgadb to add the appropriate line (diff) and 
> inject that into the install ISO, and it now does produce some output with 
> `aux/vga -m xga -l 1024x768x16`. (it does not work with -m vesa.) this gpu 
> technically supports 24-bit color modes, but vga dies telling me there's 
> not enough memory if i try to use one, which is also a known problem on 
> solaris that they say to fix by using a 16-bit mode.  

The device's pci did may be missing from /lib/vgadb simply because no one
has tested that particular device, but since you can at least get a picture,
it can be added, especially if modesetting with vesa doesn't work.


> the issue now is that although i can get the display to load, the screen 
> output is garbled. it properly renders the cursor, including its movement, 
> and responds to my keyboard too, but everything else is totally broken. it 
> IS clear where the things displayed on the screen are coming from, so it's 
> not like it's just dumping nonsense from memory. i'll link two pictures 
> showing what this looks like - the first is the initial screen the 
> installer drops to where it asks for mouse type, the second is the default 
> rio layout after hitting enter on that screen:

I think this is a bug either in vga(8) or elsewhere and it's not limited to
this driver.  My 380d with a neomagic gpu behaves similarly (sysinfo: [1]).
24bit modes cannot be enabled, though you could try the same command 2-3
times in a row, this sometimes works on these drivers despite the memory
errors, though probably without useful results.  I also had a garbled
picture, but only on the bottom of the screen, again indicating similar
memory issues.  Using a *lower resolution* works.  An even lower resolution
with 24bit color may have worked too, I don't remember.  The cursor is ok
probably because it's the hardware cursor, which is handled elsewhere
(someone please correct me if I'm wrong).

Hardware issue or bugs, there are no two ways of fixing it.  These drivers
are very old and no one has touched them since forever, mostly because no
one has really used 9front on hardware this old, and those who have haven't
arsed to fix them (sorry).  I could try to look at my 380d at some point if
it still even boots and the stupid pcmcia dongle works, but these are empty
promises.  If you'd like to try debugging this, we'll help however we can.

Hope this clears it up somewhat,

qwx

[1] http://plan9.stanleylieber.com/hardware/thinkpad/380d/2635-3au/sysinfo

  reply	other threads:[~2021-09-05 23:05 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-05 17:30 lyndsay lastname
2021-09-05 22:52 ` qwx [this message]
2021-09-05 23:18   ` lyndsay
2021-09-06  0:08     ` qwx
2021-09-06  0:53       ` lyndsay
2021-09-06 21:29         ` qwx
2021-09-21  4:11       ` lyndsay
2021-09-21  5:06         ` unobe
2021-09-21  9:17         ` qwx
2021-09-21 14:45           ` lyndsay

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