[LinuxBIOS] badly initialized (?) pci bridge on the M57SLI (with irq table and mptable)

echelon at free.fr echelon at free.fr
Mon Oct 8 03:27:20 CEST 2007

Hi Ward,

 I don't think that my little "quickie" deserves so much consideration, but I
will post it, hopping that it could be usefull for someone..
 Btw you have to do first a "setpci -s 00:01.1 64.l" to retrieve the base
address of the SYSCTRL register table. Use this value as a parameter for my
program to dump the io configuration (the gpio registers seem to start @ offset
0xc0 into this table..)
 Hope this helps,

Quoting Ward Vandewege <ward at gnu.org>:

> Hey Florentin,
> Fascinating!
> On Fri, Oct 05, 2007 at 03:00:15PM +0200, echelon at free.fr wrote:
> >   - 3) Btw I figured out that registers of the "IO control unit" of mcp55
> can be
> > mapped into the IO space by writting into the SYSCTRL_REG of the 00:01.1
> pci
> > device integrated into the SB. Indeed by using this value as a base (under
> > Linux, this register holds the value 0x1400) one can access the GPIO
> registers
> > of MCP55 (beginning @ the 0xc0 offset? maybe..) These are 8 bit registers
> > apparently..
> >   - 4) After booting with the proprietary Award bios, I dumped this table
> under
> > Linux (with a simple custom utility that I wrote for this purpose..). I
> dumped
> > 256 bytes from 0x1400.
> Would you mind sharing this utility with the list? It could be a very handy
> debugging tool.
> Thanks,
> Ward.
> --
> Ward Vandewege <ward at fsf.org>
> Free Software Foundation - Senior System Administrator

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