[SeaBIOS] SeaBIOS recognising USB 3.0 on boot works - partly
kevin at koconnor.net
Sat Dec 19 01:46:10 CET 2015
On Sat, Dec 19, 2015 at 01:11:34AM +0100, Peter Stuge wrote:
> Kevin O'Connor wrote:
> > > > > Would checking the connection status for each device after all
> > > > > devices have been registered be able to filter the USB2 device out?
> > > >
> > > > Yes, but there isn't a way to "unregister" the drive once it's been
> > > > registered.
> > >
> > > Oh - why not?
> > >
> > > If this has to do with e.g. BBS then maybe first register internally
> > > during probing, then filter disconnected devices out, *then* register
> > > "for real" ?
> > Doing that is equivalent (unless I've missed something) to delaying
> > registration until detection completes on all other ports on that
> > controller. That's the delay I'm leery of adding.
> Hm - maybe I'm missing something?
> Doesn't it effectively take the same amount of wall clock time?
Delaying registration vs unregistering would (I believe) take the same
wall clock time.
If you're asking if current state vs unregistering/delaying would take
the same wall time - thinking about that now, it might be true. I
guess the implementaiton and how things like CONFIG_THREADS=n are
handled would determine that.
> Is your worry that by postponing registration some oddities could
> come up e.g. in option ROMs that also parse the boot device list?
> I looked at the code - technically it seems straightforward to
> implement a boot_remove_hd(). Is that disallowed by the BBS?
That's not my concern. I think it would be confusing to add and then
remove. Simpler to only add when we know it's real.
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