Am 23.06.2011 01:04 schrieb David Hendricks:
I'm still not sure what the best course of action is for dealing with the D16 versus Q16 evil twin scenario. Let's see if Carl-Daniel has further comments.
Signed-off-by: David Hendricks dhendrix@google.com
As we discussed on IRC, this particular chip supports "Serial Flash Discoverable Parameters" (SFDP). I tried to add support using the values listed in Table 9 of their datasheet, and left a TODO to update the probe routine later on.
Ah yes, SFDP. Stefan has implemented a patch to support that in the meantime.
On Wed, Jun 22, 2011 at 9:15 AM, Stefan Tauner wrote:
somewhere below... +#define EON_EN25QH16 0x7015
Done. I rearranged the EN25Q* #defines a bit so they're in alphabetical order with respect to the other EN25* chips.
Index: flashchips.c
--- flashchips.c (revision 1285) +++ flashchips.c (working copy) @@ -2807,6 +2807,8 @@ },
{
/* Note: EN25Q16 is an evil twin which shares the model IDbut has different write protection capabilities */ .vendor = "Eon", .name = "EN25D16",change according to the macro name chosen (if applicable see above)
The EN25D16 was there first... I'm not sure if we should change it. I imagine the D16 is out of production, but I assume *somebody* is using it.
WWCDD? (What Would Carl-Daniel Do?)
Evil twins... I have a patch for that: http://patchwork.coreboot.org/patch/1861/
The rules are simple: If two chips are identical from a flashrom POV (same command set and write/erase characteristics), combine them into one entry. If those chips differ, give them two entries and mark them as evil twins. Differing write protection is a corner case... we don't really have a good write protection handling in flashrom (yet), and until one of the four suggested/implemented designs is chosen, this is difficult to handle. Is there a way to probe for the write protection capabilities?
Side note: Probing could be a bit more intelligent for the case of almost-identical chips. It could calculate the greatest common command set and offer to use that merging result. Other tricks are possible as well.
Regards, Carl-Daniel