Am 04.01.2011 um 21:57 schrieb Alexander Graf:
On 27.12.2010, at 01:25, Andreas Färber wrote:
Am 27.12.2010 um 01:11 schrieb Alexander Graf:
Am 27.12.2010 um 00:28 schrieb Andreas Färber <andreas.faer...@web.de
>:
Am 14.12.2010 um 01:49 schrieb Andreas Färber:
Workaround the following error:
qemu: hardware error: register_ioport_read: invalid opaque
I found out that this is a conflict with i8042 registering I/O
port 0x0092 in pckbd.c, too.
Not sure what the proper fix should look like - add some qdev
property to ISAKBDState to disable the port?
Well, why does the PREP board have its own mapping there in the
first place? It should be the same as a PC from a port pov, no?
Why does the i8042 controller have a System Control Port in the
first place rather than the 'pc' machine? :)
The PReP spec v1.1 has a Special Port 0x0092 that includes two bits
of significence - softreset and endian mode. So wherever the port
is registered, the latter behavior is board-specific and does not
match pckbd.c (A20 gate or HDD activity depending on bit numbering).
A similar issue arises between PReP machines: The ioport currently
does not allow using a different opaque for reads and writes to the
same address. So either we need to change ioport or create some
inheritence/override mechanism for port behavior.
Hmm - sounds to me like that register simply doesn't belong there
then, so a split would be the correct solution. The alternative
would be to have the keyboard controller create a bus that those
bits send signals to. An x86 system could then implement its A20
gate in x86 specific code while PREP could do its specific stuff.
Coincidentally there's a recent pckbd patch from Blue that resolves
the conflict. Feel free to review. :)
Any thoughts on the read vs. write port issue? Do we need to register
both ports in the base device and add hooks to the device state?
Sounds problematic VMState-wise, just like some of the qemu_irq
constructs in the ppc devices. (My prep_pci changes are still far from
perfect, UniNorth has similar issues I noticed.)
Andreas
