Re: [9fans] Parallels Vesa driver question

[Daniel Lyons <fusion@storytotell.org>]

Erik,

Thanks for your speedy assistance! I think the two things are closely  
interrrelated via the global variable hardscreen. Reverting this file  
solved the problem. I wouldn't be surprised if there were something  
weird about Parallels' MTRR support, and since this isn't the current  
version it's not likely to get any better. If anyone's using Parallels  
4 and not running into this issue, I'd love to know.

Also, are the old sources available online somewhere so I can do this  
kind of diff in the future on my own?

Thanks again,

On Aug 2, 2009, at 11:06 AM, erik quanstrom wrote:

> On Sun Aug  2 05:39:10 EDT 2009, fusion@storytotell.org wrote:
>> Hi,
>>
>> I installed Plan 9 under Parallels 3 back in November of last year  
>> and
>> it worked without a hitch. I tried to install another copy tonight  
>> and
>> the bitmapped display isn't working in the new one, I just get a pure
>> black screen after any aux/vga command that it thinks will succeed. I
>> found I can reproduce that behavior by building and running a new
>> kernel in the old install. Any ideas what has happened since November
>> in the kernel with respect to Vesa and Parallels? I'd be more than
>> happy to debug this issue if I could get a little guidance. I didn't
>> see anything in the archives about this problem. Alternatively, does
>> anyone know if Parallels 4 works with a current kernel? If so I'll
>> probably just upgrade to that; I've been holding off for a good  
>> reason
>> to.
>
> two things: mtrr and adding a vesaflush command.  it doesn't quite  
> make
> sense to me that this would break parallels, unless there is something
> funky about
> - mtrr ranges with parallels.
> - parallels vesa
> - plan 9 vesa support
>
> the easiest thing to do would be to comment out vesaflush and
> see what happens.  without pawing through the standard, it may
> be that vesaflush is optionally supported and parallels doesn't  
> support it.
>
> - erik
>
> ; diff -c vgavesa.c /n/sourcesdump/2008/1101/plan9/sys/src/9/pc/ 
> vgavesa.c
> vgavesa.c:13,21 - /n/sourcesdump/2008/1101/plan9/sys/src/9/pc/ 
> vgavesa.c:13,18
>  #include <cursor.h>
>  #include "screen.h"
>
> -
> - static void *hardscreen;
> -
>  #define WORD(p) ((p)[0] | ((p)[1]<<8))
>  #define LONG(p) ((p)[0] | ((p)[1]<<8) | ((p)[2]<<16) | ((p)[3]<<24))
>  #define PWORD(p, v) (p)[0] = (v); (p)[1] = (v)>>8
> vgavesa.c:83,89 - /n/sourcesdump/2008/1101/plan9/sys/src/9/pc/ 
> vgavesa.c:80,86
>  }
>
>  static void
> - vesalinear(VGAscr *, int, int)
> + vesalinear(VGAscr* scr, int, int)
>  {
>  	int i, mode, size;
>  	uchar *p;
> vgavesa.c:130,169 - /n/sourcesdump/2008/1101/plan9/sys/src/9/pc/ 
> vgavesa.c:127,135
>  		size = ROUND(size, 1024*1024);
>
>  havesize:
> - 	if(size > 16*1024*1024)		/* probably arbitrary; could increase */
> - 		size = 16*1024*1024;
> - 	hardscreen = vmap(paddr, size);
> - 	mtrr(paddr, size, "wc");
> - //	vgalinearaddr(scr, paddr, size);
> + 	vgalinearaddr(scr, paddr, size);
>  }
>
> - static void
> - vesaflush(VGAscr *scr, Rectangle r)
> - {
> - 	int t, w, wid, off;
> - 	ulong *hp, *sp, *esp;
> -
> - 	if(rectclip(&r, scr->gscreen->r) == 0)
> - 		return;
> -
> - 	hp = hardscreen;
> - 	sp = (ulong*)(scr->gscreendata->bdata + scr->gscreen->zero);
> - 	t = (r.max.x * scr->gscreen->depth + 2*BI2WD-1) / BI2WD;
> - 	w = (r.min.x * scr->gscreen->depth) / BI2WD;
> - 	w = (t - w) * BY2WD;
> - 	wid = scr->gscreen->width;
> - 	off = r.min.y * wid + (r.min.x * scr->gscreen->depth) / BI2WD;
> -
> - 	hp += off;
> - 	sp += off;
> - 	esp = sp + Dy(r) * wid;
> - 	while(sp < esp){
> - 		memmove(hp, sp, w);
> - 		hp += wid;
> - 		sp += wid;
> - 	}
> - }
> -
>  VGAdev vgavesadev = {
>  	"vesa",
>  	0,
> vgavesa.c:174,178 - /n/sourcesdump/2008/1101/plan9/sys/src/9/pc/ 
> vgavesa.c:140,145
>  	0,
>  	0,
>  	0,
> - 	vesaflush,
> + 	0,
>  };
>

—
Daniel Lyons