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Re: PCI VGA Card Initilization (SIS6326 / PT80)

To: "MIPS/Linux List \(SGI\)" <>
Subject: Re: PCI VGA Card Initilization (SIS6326 / PT80)
From: "Girish Gulawani" <>
Date: Wed, 20 Mar 2002 23:15:15 +0900
hello again.
with regards to previous replies to my post -- the isa_readb() i am not
using as i am still inside the linux loader program & not inside the linux
kernel. now it seems what Zhang says is right. that some cards cannot be
fired up without their BIOS.
meantime today i could access VGA ROM BIOS at 0xC_0000 for no use as its x86
code. i tried free-bios source code, which has VGA bios code for SiS300. its
able to bring up monitor to normal mode out of powerdown mode. screen even
displays "Out of Scan Range" message. but nothing after that. in order to
compare initialization steps between SiS300 & my target SiS6326, i tried to
get the data sheet from website but the data sheets are not
available. could any body point me where the data sheets for SiS300 and
PT-80 VGA card are available?

btw, i wonder what card you people are using for VGA monitors? and what
about their initialization on the MIPS board? is there ANYBODY who has used
"AOpen's PT80" or ANY VGA card based on SiS6326 chipset on MIPS board & how?
if somebody has done this exercise could you please explain, because i am
sure this will be of general interest.

[to summarize my problem with PCI/VGA card -- currently i am using MILO bios
source code. the card has 3 BARs.
BAR0 = PCI Memory Area. BAR1 = 0xA_0000 (VGA MemIO Buff) BAR2 = 0x0380 (IO).
with these settings the IO access from CPU is ok. but any access to A0000
fails. my PCI is not PCI-to-PCI bridge, hence no question of VGA Enable.
also the PCI bus analyzer does show memory read & memory writes commands
being generated when accessed A0000 address. to add to this - i guess my
options to choose the card are also limited as i have 3.3v PCI slot.]

please help me.
many thanks in advance.

----- Original Message -----
From: "Zhang Fuxin" <>
To: "Girish Gulawani" <>
Sent: Tuesday, March 19, 2002 12:00 AM
Subject: Re: Re: PCI VGA Card Initilization (SIS6326 / PT80)


 could that be the famouse vga bios initialization problem? That is,
without executing the vgabios code,video card often refuse to work.
And unfortunately vgabios code is often for x86.

?ú 2002-03-19 08:46:00 you wrote£o
>> > i have a PCI/VGA card PT80 with SIS6326 chipset. i am using MILO BIOS
>> > code. but i am not able to access the internal buffer which is
>> > 0xA0000. even the BIOS ROM (0xC0000) read fails to show default value
>> > 0xA5A5. the expansion ROM is enabled in PCI by setting D0 bit to 1.
>> > IO seems okay because the monitor actually switches from power down
>> > normal mode. i have tried using both vgaraw1.c and vgaraw2.c files, but
>> > success. could anybody help me to solve this problem.
>> > many thanks.
>> Are you using isa_readb() and friends to access ISA memory space?
>> Did you set up isa_slot_offset correctly with the start address of ISA
>> space on your MIPS box?
>no i am not using isa_readb() etc. infact i am accessing this area 0xA_0000
>as Memory/IO in memory mode. i have seen the pci bus transactions, its
>generating memory read and memory write commands. but due to some reason
>that is still *unknown* to me generates master abort. i always get master
>received master abort. could you tell me what could be the reason?
>Do You Yahoo!?
>Get your free address at

            Zhang Fuxin

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