On 16.06.2008 19:02, Stefan Reinauer wrote:
Carl-Daniel Hailfinger wrote:
On 14.06.2008 21:53, Stefan Reinauer wrote:
I suggest using the same mechanism, wrapping the information in a lar header, making it a single file lar. The lar format can handle this, and we don't have to worry for different versions.
How about a generic bootblock/VPD signature instead? Having a short signature in the top 256 bytes or so will allow recognition of complete and incomplete (only partly mapped) coreboot images easily.
Proposal for signature formats:
4 bytes: "CB20" for v2.0 and "CB30" for v3.0
8 bytes (option 1): "CB203300" for v2.0, rev 3300
8 bytes (option 2): "coreboot"
16 bytes: "coreboot20r3300 " for v2.0, r3300 (note the space at the end for 5-digit svn revisions)
Top 256 bytes will not always work. The current trouble is due to the fact that we have some mainboards that need the information in a different place than others.
Anything in the top 4k would be OK for me, unless there are specific reasons this is impossible with some boards. I'd appreciate a pointer about the "different place" thing.
Other than that, we might indeed put the coreboot version into the firmware signature, too, if there's a reason to do so. Is there?
Not sure about svn revision, but differentiating between v2 and v3 would help. For one, we could keep a pseudo-LAR out of v2.
I miss the actual information in your suggestion, namely the mainboard vendor and type.
Placing vendor and type somewhere else is possible, as long as flashrom knows that it should look there.
Since we already have LAR, using that format instead of yet another signature rule makes a lot of sense in my opinion.
For v3, yes mostly. For v2, someone would have to add a invalid LAR pseudoheader to the final linked image. Definitely not something I'd like to try (my linker script skills are not good enough nor do I consider this to be a particularly compelling idea).
Regards, Carl-Daniel