Il 05/03/2013 20:12, Laszlo Ersek ha scritto:
On 03/05/13 17:59, David Woodhouse wrote:> On Tue, 2013-03-05 at 17:03 +0100, Paolo Bonzini wrote:
Resuming from suspend-to-RAM should not reset all devices. Only the CPU should get a reset signal.
Hm... on reflection, I don't actually know if this is true.
Perhaps we *should* reset all devices. After all, in a real machine they'll all have been turned off and the RAM will have been in self-refresh. Surely they have to be reset?
So maybe we should *let* the i440FX PAM registers get reset to point to ROM. And fix the firmware to *cope* with that, check to see if the shadow RAM already holds an image of a started-up firmware with the correct checksum, and jump back to it.
That is: perhaps it's a *SeaBIOS* bug that suspend/resume doesn't work if the PAM configuration is reset?
I think it is indeed a problem with SeaBIOS. Open romlayout.S: [...]
It checks the CMOS only after looking at HaveRunPost. The value of HaveRunPost depends on the PAM settings. It's always 0 in ROM, in which case we continue at handle_post() [src/post.c].
Actually, Peter explained that it is okay. S3 doesn't clear the PAM configuration, but S4 does. The PAM registers are attached to the same power line as the RAM.
Paolo