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Subject:  Re: [9front] core-i3 and vesa mode
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X-Glyph: ➈
X-Bullshit: immutable GPU solution 

I don't understand it well.
Then, I added print() commands in gmsize() of
/sys/src/9/pc/vgaigfx.c:
static uintptr
gmsize(Pcidev *pci, void *mmio)
{
	u32int x, i, npg, *gtt;


print("stolen index = %d\n", (pcicfgr16(pci, 0x50)>>3) & 0x1f);
print("stolenmb = %d\n", (u32int)stolenmb(pci));


	npg = stolenmb(pci)<<(20-12);


print("npg = %ux\n", npg);

	if(npg == 0)
		return 0;
	gtt = (u32int*)((uchar*)mmio + pci->mem[0].size/2);


print("gtt = 0x%ux\n", *gtt);

	if((gtt[0]&1) == 0)
		return 0;
	x = (gtt[0]>>12)+1;


print("x = 0x%ux\n", x);

	for(i=1; i<npg; i++){
		if((gtt[i]&1) == 0 || (gtt[i]>>12) != x)
			break;
		x++;
	}

print("i = %ud\n", i);

	if(1) print("igfx: graphics memory at %p-%p (%ud MB)\n", 
		(uintptr)(x-i)<<12, (uintptr)x<<12, (i>>(20-12)));
	return (uintptr)i<<12;
}

I boote up the system with BIOS menu of:
Aperture size = 256MB, GTT size= 2MB, DVMT Pre-Allocated = 64 MB,
DVMT Total Gfx Mem = MAX
and got the results like:

stolen index = 2, stolenMB = 62, npg = 3e00, gtt = 0xdba00001
x = 0xdba01, i=15872
igfx: graphics memory at dba00000-df800000 (62MB)
storage = 0x3dfc000
I think those values are reasonable.

However, in this case pci commands reports for the video device:
02.0: vid 03.00.00 8086/0152 11 0:f7800004 4194304 2:e000000c 268435456
4:0000f0001 64.

As seen from the result, our graphics memory is out of the range of 
e000000c - (e000000c + 268435456).

Of course, the system stalls after the print() command.

How do you think?

Kenji