Thomas Renninger wrote:
On Thu, 2007-08-09 at 15:16 +0000, Pavel Machek wrote:
Hi!
firmwarekit-discuss <firmwarekit-discuss@xxxxxxxxxxx> (added to CC list)
see: http://linuxfirmwarekit.org/
But if I understand this problem right, this won't be easy.
The ACPI tables are just parsed with system ("iasl ...") and syntactical
errors/warnings are printed out.
I also thought about a test, interpreting the DSDT and read out values
of cpufreq tables and sanity check them. AFAIK the linuxfirmwarekit is
not designed for that atm. You need to compile in most parts of the
acpica code and parse and interpret DSDT/SSDT code yourself in the
firmwarekit core or inside a plugin, then do a walk_namespace call or
whatever to find the functions/parts you like to examine. This is a lot
work and needs a proper design (providing an interface to plugins to let
them easily check specific AML/ASL code).
Furthermore, we don't really know what we're looking for. How can you
tell a given write to an ioport is issuing STANDBYNOW to an ATA disk or
trying to power the machine off? Adding to the fun, many modern ATA
controller have more than one way to issue a command. Maybe we can
match accesses inside regions specified by PCI BARs.... :-(
Hmmm... perhaps we should do it the other way. ACPI is allowed to
touch the embedded controller, what else? Maybe we should warn as soon
as API touches non-EC I/O port?
This is not working...
ACPI can and does access all kind of other I/O ports and other
resources.
Hmm, are the disk accesses done by ACPI via OperationRegion/Field
declared variables?
I try to get a check for those clashing with native drivers (hopefully
this approach is successful for 2.6.24, can't say for sure yet), I
wonder whether this one would give a warning like "Libata driver is
using the same SystemIO/SystemMem resources than ACPI OperationRegion
declaration XY".
This would not solve the problem, but at least show the need of such a
test. Such ACPI vs native driver interference problems are very hard
nuts (in identifying and solving).
Can someone post an ASL code snippet how ACPI actually access the disk
and in which parts/functions, pls.
Again, it's not believed that this is being done via AML, but via a BIOS
SMM trap on the ACPI sleep state hardware IO port. We have no real
ability to find out what the BIOS is doing or prevent it in this case.
--
Robert Hancock Saskatoon, SK, Canada
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Home Page: http://www.roberthancock.com/
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