Hi again Brendan,
On Mon, Jan 28, 2008 at 08:04:28PM +0000, Brendan Trotter wrote:
On 1/27/08, Peter Stuge peter@stuge.se wrote:
What, specifically, do you need?
For long-term viability, I need something (e.g. a formal specification) that gives guarantees on the (past, present and future) behaviour that a payload can expect from Coreboot, which includes considerations for both forward and backward compatability.
This is not very specific, quite the contrary this is completely generic. I asked so you can tell us what you would like.
Yes, and the structure used by entries in the coreboot table is a good start (e.g. "type + length + data", where unrecognised entries defined in later versions of coreboot can easily be skipped by older payloads that don't recognise these entries). But this alone isn't enough,
Very true.
Payloads are 32-bit (and maybe 64-bit, and possibly compressed?) elf binaries, but does coreboot support relocations? If the payload is linked to be loaded at the fixed address 0x40000000 will it work if the computer only has 128 MB of RAM?
Is this functionality that you need?
What happens if the payload's main function returns to coreboot? Which arguments are passed to the payload's main function?
The payload can not return. Coreboot does not leave a return address on the stack. When the payload is started, Coreboot is history.
On 1/27/08, Peter Stuge peter@stuge.se also wrote:
It would be great if you would help create this.
I wouldn't consider it appropriate for a relative stranger who has no intention of becoming a project member/developer (ie. me) to create a specification
I disagree. This is one great thing about open source.
Specifically because noone else has created what you need, it is not only appropriate but also encouraged if you, however strange you are, would contribute on the matter. With that contribution (and actually with this discussion) I already consider you a member of the project. All is not code.
that all future versions of coreboot must comply with.
I think this is a separate discussion. I realize it is crucial to you, but perhaps the discussion can lead to new innovations which can loosen requirements.
This sort of specification is something the project leader should write (or IMHO, should have written).
That's not really a community development model, is it? That sounds like a very hiearchichal model, which is not too common in small projects like our own.
Open source for me is all about anyone and everyone contributing whatever they can when they can and want to.
There is a compromise here though: I'm willing to write a *draft* specification (in HTML format), that coreboot project members could use as a reference or as the basis for their own specification.
As you may have noticed from following the list, this is exactly how we work - someone makes a suggestion, people iterate on it and discuss, eventually arriving at code, or the trashcan. :)
The draft specification would be mostly a work of fiction - something that specifies how I would do things if I was doing things, rather than something that specifies how coreboot members will do things or how coreboot members have done things...
I think it would be awesome if you could do that! No need to make it fancy, a plain text email to the list is perfectly fine. (And may actually be prefered over HTML for some project members.)
//Peter