New subject: vga not working

21 Aug 2009


      As an additional information, I've seen that :
1)
coreboot was running at 0x4000. I've changed  Options.lb in 
mainboard\intel\truxton :
-- default CONFIG_RAMBASE=0x00004000
++ default CONFIG_RAMBASE=0x00100000
This did not compile so I've had to add :
++ uses CONFIG_LB_MEM_TOPK
++ default CONFG_LB_MEM_TOPK = 2 * 1024 * 1024
This did not change anything to the VGA problem, I think I will keep 
this that way, what
you guys are thinking about this?
2)
My auto.c patch is not consistent as this is called prior the 
enable_resource function in
fact. The function enable_resource is using logical or operations. In 
this case I still gets
some unwanted bits obviously. Actually yesterday I was very tired I 
guess. The value
0xb means 0b1011 :
2PERRE = 1, 2SERRE = 1 and VGAEN = 1.
I am not sure 2PERRE or 2SERRE would be any relevant around my problem. 
But the
legacy BIOS do not set these to 1, this is a fact.
Actually what is the best way to get pciexp_porta.c to be included and 
replace the
default PCI functions in src\devices ?
As an additional question:
1)
Can these memory holes be cached or not. I guess these ranges should not 
correspond to a
cacheable RAM section. Does coreboot cache the complete  0x0 to 
CONFIG_LB_MEM_TOPK area.
The chipset configuration provide the complete memory range as coherent 
memory.
Thank you
Arnaud
Arnaud Maye wrote:
...
Myles Watson wrote:
...
...
The ep80579 has two x4 lanes peripherals (00:02.0 and 00:03.0) both of
You mean the i3100 here, right?
Yeah the EP80579 is a SOC ( System on chip ). It includes a IA32 core, 
a North Bridge and a
South Bridge all on the same chip. In this respect talking about i3100 
is not very correct I believe.
It is clear they have a i3100 core there inside. it is just not named 
in fact. The ep80579 has an
IMCH and a IICH.
The northbridge and southbridge are connected by a NSI ( North-South 
Interface ). This is in
fact a custom transparent PCIe implementation. So finally most of the 
devices are on bus 0.
...
...
them having a register 0x3E. If you set
ISAEN on 00:02.00 you have to set ISAEN on 00:03.00 as well. This is a
requirement provided by Intel in fact.
It makes sense as the address decoding is different as soon ISAEN is
set. All th bridges should be set correctly.
These two peripherals can be coupled together providing x8 lanes.
Note that ISAEN is not set by the legacy BIOS, and the VGA output is
working flawlessly. So in fact I just want
to write 0x8 instead 0xb in register 0x3E. But this I can already do,
just not at the correct place.
So where have you tried?  File and function?
It looks like if that's the bit you want to set you need to have your 
own
enable_resources function in pciexp_porta.c.  Right now you're using the
default.
In auto.c ( mainboard\intel\truxton ) I've created a enable_vga() 
function which only
pci_write_config(dev, 0x3e, 8).
This function is called at the end of auto.c's main() after the 
ram_fill/ram_verify.
I agree, I need my own enable_resources function. This is the patch 
I've tried to do. I've attached
the patch. In fact it is not called because I did not include it. I 
did expect this file to be
correctly included as it is part of the initial port.
As you can see I have added a printk in pcie_init and I do not see 
that on the log.
...
...
With the GFX card connected to SLOT0, the PCIe is operating in coupled
mode and actually configured as x8.
This is because the current coreboot port does not set PEACAPA.SIMP 
to 1
in both bridge. As soon both 00:02.0
and  00:03.0 get PEACAPA.SIMP is set to 1, the two port are configured
in x4. We can see that in
PEALNKCAP.MLW. Checking legacy BIOS settings confirm PEACAPA.SIMP 
should
be 1 in both PCIe
ports.
So this should probably be done even earlier.  That's not something 
that is
fixed, right?  Or do you want it coupled (or not) depending on what card
gets plugged in?
Actually for a very generic port we should come up with some config 
options. About the truxton board,
We have an architecture like the following :
PCIe PEA0 (4x) -> SLOT0
PCIe PEA1 (4x) -> PCIe SWITCH -> SLOT1 (1x), SLOT2 (1x), SLOT3 (1x), 
SLOT4 (1x)
For a truxton BSP we should not have both ports coupled as a (8x), 
Just imagine if you decide to have
a GFX card on slot 0 and a ethernet card on SLOT2, this is not going 
to go very well.
I think having some CONFIG option for this would be great. And I think 
this should indeed happen
in pcie_init().
Actually, there a are a few other things like that which are not 
important to describe so far I believe.
Verifying all the registers value takes time. lspci legacy vs coreboot 
shows a lot of differences and
in this respect I am checking them one by one using the datasheet. So 
it is likely some other things
will pop up.
...
...
I guess the only thing left is that coreboot does not allocate a hole
for the VGA, two holes are required I guess,
MEM and IO. how can I check if a hole is actually reserved or not?
Look through the last resource tree in the boot log.  It should be 
there.
You can always add them in read_resources.
I have attached my last log. I believe we have the correct hole :
PCI_DOMAIN: 0000 resource base 0 size a0000 align 0 gran 0 limit 0 
flags e0004200 index 3
PCI_DOMAIN: 0000 resource base c0000 size 1ff40000 align 0 gran 0 
limit 0 flags e0004200 index 4
We do not have anything between 0xa0000 and 0xc0000. These areas are 
in fact VGAA, MDA and
VGAB.
Anything else I should verify?
Thank you,
Arnaud
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Re: [coreboot] vga not working