Perhaps i2c/smbus.
Clay Jones senior software engineer | [EMAIL PROTECTED] | www.f5.com P. 509 343 3500 | F. 509 343 3501 | D. 509 343 3519 F5 Networks | 1322 North Whitman Lane | Liberty Lake, Washington 99019 The Leader in Application Traffic Management Ensuring secure and optimized application delivery for global enterprises -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Carl-Daniel Hailfinger Sent: Thursday, November 30, 2006 9:07 AM To: [email protected] Subject: Re: [LinuxBIOS] Support for recent chipset and powerful desktop CPU Peter Stuge wrote: > On Wed, Nov 29, 2006 at 05:17:01PM -0700, ron minnich wrote: >> we are going to have to learn USB debug port. This problem is not >> going away. > > Maybe we can find some other solution that is even easier to use. > > > On Thu, Nov 30, 2006 at 04:19:26AM +0100, Segher Boessenkool wrote: >> But yes, it's very unfortunate "modern" systems are >> so unfriendly to low-level bringup. At the very least >> it makes it really really hard to have some uniform >> ("generic") working early setup code. > > What other buses are usually available, that we could abuse to get > output with little hardware effort required? > > While I would love to see an affordable PLCC thing that implements a > reads-make-a-write protocol it's not ready today nor tomorrow, while > the KN9 Ultra is getting older already. > > What signals can be twiddled at, or soon after, power on? > > Ideally we want a channel that is not required at all for bringup. > > Ideally it would be able to run at both kHz and MHz to test/provoke > timing issues, but if single speed I guess kHz is easier to handle. > > > LPC > Pro: Available immediately after power on > Con: Logic needed to decode > Con: Mechanical issue, hard to hook up > > DRAM > Pro: Easy to make/get/order PCBs that fit > Con: Not easily accessible without setting up DRAM controller > (Is this the case?) > Con: Need fast logic to decode. > (Is this the case? Can modern DRAM controllers be set to run slowly?) > > IDE > Pro: Simple 8-bit PIO, easy to interface with > Con: Needs SuperIO running, at least a little, like the serial port. > > > What other candidates are there? What can code do that is easy to > measure? Power? Voltage? One bit is enough. Am I insane? :) SPI When all vendors move to SPI, hopefully most boards will have a debugging header or another method to hook into SPI. Pro: Fast, soon to be the standard Con: No idea what support we need for writing to SPI Regards, Carl-Daniel -- http://www.hailfinger.org/ -- linuxbios mailing list [email protected] http://www.openbios.org/mailman/listinfo/linuxbios -- linuxbios mailing list [email protected] http://www.openbios.org/mailman/listinfo/linuxbios
