Subject: PCI config cycles from ddb
To: None <,>
From: Steven Grunza <>
List: tech-kern
Date: 03/15/2000 13:46:45
I'm trying to hack the Yamaha YMF724 sound chip hanging off the PCI bus on
my Dell motherboard.  There is supposed to be a SoundBlaster Pro emulation
mode.  What I need to do is hack at the config registers through DDB until
it starts working.  The problem is the access method to get to the PCI
config space on port-i386 looks to require IO instructions (inl and outl). 

It doesn't look like ddb directly supports the inl and outl instructions
but it should be possible to add them by using port-i386 specific additions.  

Before I do this, has someone else done it already?  I didn't see anything
in /sys/arch/i386/i386/db_interface.c that would imply the support is
already there...

The alternative would be the ability to call pci_config_read() and
pci_config_write() directly from the ddb command line.

I'm open to any suggestions for the best way to proceed with this.....

Dell won't give out programming info and Yamaha wouldn't know how Dell
integrated the Yamaha chip onto the Dell motherboard.  I'm beginning to
suspect that whoever said Dell support was great either never used Dell or
never had a technical question for them.

Steven Grunza