ACPI DSDT

[ron minnich]

On Tue, 1 Jun 2004, Steve Gehlbach wrote:

> Speaking of ACPI and problems, which are commented on in this article, 
> is this Intel announcement of open sourcing the BIOS something new?
> 
> http://news.com.com/Intel+to+open+code+for+booting+up+PCs%2C+servers/2100-7337_3-5223860.html?tag=nefd.top

You are not going to get the hardware startup code in Tiano. You're going
to get the code that runs on top of the hardware startup code, and gives
you a DOS-like startup system. Don't expect to suddenly see northbridge
code on the intel web site. Part of the goal of Tiano/EFI is to make the 
release of such information unneeded. 

There is a silver lining. Supposedly, the interfaces from the hidden 
hardware code to Tiano will be public. This means you can conceivably 
chuck Tiano and put your own thing in its place, which could be ... a 
Linux kernel! You might need a small shim from the hidden hardware code to 
Linux, which could in turn be ... LinuxBIOS!

This is how Linux NetWorx built the Alpha LinuxBIOS: 
- hidden hardware code (Alpha SROM) [ not changed, left in place]
- LinuxBIOS [with Alpha support, minus memory setup code]
- Linux

Worked fine, should work for Tiano platforms. In other words, the binary 
support code for Tiano could solve some problems for us: 
- if we don't get the specs for the Intel chips (likely), then we can 
  just leave the "hidden hardware code" in place, and flash over
  Tiano, replacing Tiano with LinuxBIOS. I believe Linux Labs 
  did something like this for their ClearWater port 2 years or so ago.
- Makes porting to other Intel mobos easier. 

Why the CPL, not the GPL? So that 3rd party vendors can add
incompatibilities -- err, value -- and charge you for it.

Put another way, Tiano could be a linuxbios payload. I don't have much use
for a Tiano/EFI payload, however. Tiano/EFI is very complex and if I'm
going to put a complex thing like that into flash I'd much rather it be
linux. I don't want something that's most of the work of an OS but not
much of the capability, which pretty much describes Tiano/EFI.

I'm intrigued that they are open sourcing it. I had for years only heard 
that it would be available under a type of NDA. I think LinuxBIOS is part 
of the push for open sourcing this type of software. But I doubt you're 
going to see Phoenix et. al. open source their 'value-added' Tiano, which 
means a source fork is built into the model. That's trouble for us as 
customers -- we already suffer daily with all these BIOS extensions and 
undocumented, hidden gotchas. We already say this once: there was supposed 
to be a standard "hand off" on IA64 for startup. I found out that this 
"standard" handoff was modified by several vendors: it was no longer 
standard. Let's hope the "hidden hardware code" to Tiano interface remains 
standard. 

Also, if this code is anything like the EFI code, it won't build under 
Linux, only builds under Windows. It won't "just work" for us. 

All that said, I think Intel is doing a good thing by open sourcing the
Tiano system, and I congratulate them on doing so.

ron