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Re: [Qemu-devel] RFC: ACPI, HPET._CRS, MacOSX vs. WinXP
From: |
Gabriel L. Somlo |
Subject: |
Re: [Qemu-devel] RFC: ACPI, HPET._CRS, MacOSX vs. WinXP |
Date: |
Mon, 20 Jan 2014 13:54:15 -0500 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Mon, Jan 20, 2014 at 01:16:02PM +0100, Paolo Bonzini wrote:
> Il 20/01/2014 13:08, Michael S. Tsirkin ha scritto:
> >>> > > I think the hack looking for the SMC device is safer than _OSI: OSPMs
> >>> > > are known to do crazy things when they see _OSI, such as assuming they
> >>> > > need to try and emulate the OS probed.
>
> Source for "OSPMs do crazy things when they see _OSI".
After a bit more digging, I believe this has to do with the fact that
OSPM is responsible for define _OSI, and referencing it from e.g. the
HPET._CRS method when it's NOT defined (e.g. by a misbehaving OSPM)
results in all sorts of unpleasantness.
In fact, looking on the MacBookPro, we see the following:
DefinitionBlock ("dsdt.aml", "DSDT", 1, "APPLE ", "MacBookP", 0x00090001)
{
...
Field (GNVS, AnyAcc, Lock, Preserve) {
OSYS, 16,
...
}
...
Scope (\_SB) {
Method (_INI, 0, NotSerialized) {
Store (0x07DC, OSYS)
If (CondRefOf (\_OSI, Local0)) {
If (_OSI ("Darwin")) {
Store (0x2710, OSYS)
}
If (\_OSI ("Linux")) {
Store (0x03E8, OSYS)
}
If (\_OSI ("Windows 2009")) {
Store (0x07D9, OSYS)
}
If (\_OSI ("Windows 2012")) {
Store (0x07DC, OSYS)
}
}
}
...
}
...
So, basically, they give OSYS a default value, then *if* _OSI is
defined by a well-behaved OSPM, they use it to give OSYS a more
useful, specific value. CondRefOf is used to avoid a fatal error
in case _OSI does not exist.
And later:
Device (HPET) {
Name (_HID, EisaId ("PNP0103"))
Name (_CID, EisaId ("PNP0C01"))
Name (BUF0, ResourceTemplate () {
IRQNoFlags () {0}
IRQNoFlags () {8}
Memory32Fixed (ReadWrite,
0xFED00000, // Address Base
0x00000400, // Address Length
_Y16)
})
Method (_STA, 0, NotSerialized) {
If (LGreaterEqual (OSYS, 0x07D1)) {
If (HPAE) {
Return (0x0F)
}
} Else {
If (HPAE) {
Return (0x0B)
}
}
Return (0x00)
}
...
}
Which begins to explain why, on the MBP2,2 I didn't see the HPET show
up in the XP device tree at all ! :)
I.e., I wonder if XP actually defines _OSI (my inner gambling addict
says it probably does not).
Long story short, we could use CondRefOf as an intermediary wrapper
around _OSI to avoid referencing SMC._STA from within HPET.CRS...
Not sure we want to "complicate" the rest of the HPET (e.g. return
different values for bit2, "show device in acpi u/i" depending on
_OSI, the way Apple machines do).
Thanks,
--Gabriel
- Re: [Qemu-devel] [PATCH] Add option to disable FDC from ISA bus and ACPI on i386, (continued)
- Re: [Qemu-devel] [PATCH] Add option to disable FDC from ISA bus and ACPI on i386, Gabriel L. Somlo, 2014/01/09
- Re: [Qemu-devel] [PATCH] Add option to disable FDC from ISA bus and ACPI on i386, Gabriel L. Somlo, 2014/01/09
- Re: [Qemu-devel] [PATCH] Add option to disable FDC from ISA bus and ACPI on i386, Paolo Bonzini, 2014/01/10
- Re: [Qemu-devel] [PATCH] Add option to disable FDC from ISA bus and ACPI on i386, Gabriel L. Somlo, 2014/01/10
- Re: [Qemu-devel] [PATCH] Add option to disable FDC from ISA bus and ACPI on i386, Igor Mammedov, 2014/01/10
- [Qemu-devel] RFC: ACPI, HPET._CRS, MacOSX vs. WinXP, Gabriel L. Somlo, 2014/01/17
- Re: [Qemu-devel] RFC: ACPI, HPET._CRS, MacOSX vs. WinXP, Michael S. Tsirkin, 2014/01/20
- Re: [Qemu-devel] RFC: ACPI, HPET._CRS, MacOSX vs. WinXP, Paolo Bonzini, 2014/01/20
- Re: [Qemu-devel] RFC: ACPI, HPET._CRS, MacOSX vs. WinXP, Michael S. Tsirkin, 2014/01/20
- Re: [Qemu-devel] RFC: ACPI, HPET._CRS, MacOSX vs. WinXP, Paolo Bonzini, 2014/01/20
- Re: [Qemu-devel] RFC: ACPI, HPET._CRS, MacOSX vs. WinXP,
Gabriel L. Somlo <=
- Re: [Qemu-devel] RFC: ACPI, HPET._CRS, MacOSX vs. WinXP, Michael S. Tsirkin, 2014/01/20
- Re: [Qemu-devel] RFC: ACPI, HPET._CRS, MacOSX vs. WinXP, Gabriel L. Somlo, 2014/01/20
- Re: [Qemu-devel] RFC: ACPI, HPET._CRS, MacOSX vs. WinXP, Paolo Bonzini, 2014/01/21
- Re: [Qemu-devel] RFC: ACPI, HPET._CRS, MacOSX vs. WinXP, Michael S. Tsirkin, 2014/01/21
- Re: [Qemu-devel] RFC: ACPI, HPET._CRS, MacOSX vs. WinXP, Paolo Bonzini, 2014/01/21
- Re: [Qemu-devel] RFC: ACPI, HPET._CRS, MacOSX vs. WinXP, Michael S. Tsirkin, 2014/01/21
- [Qemu-devel] [PATCH] ACPI: Add IRQ resource to HPET._CRS on Mac OS X, Gabriel L. Somlo, 2014/01/21
- Re: [Qemu-devel] [PATCH] ACPI: Add IRQ resource to HPET._CRS on Mac OS X, Michael S. Tsirkin, 2014/01/21
- Re: [Qemu-devel] [PATCH] ACPI: Add IRQ resource to HPET._CRS on Mac OS X, Gabriel L. Somlo, 2014/01/24
- Re: [Qemu-devel] [PATCH] ACPI: Add IRQ resource to HPET._CRS on Mac OS X, Alexander Graf, 2014/01/24