Re: [Qemu-devel] os x boot broken by commit 11948748495841bd54721b250d68c7b3cb0475ef

[Paolo Bonzini]

Il 21/11/2013 23:02, Gabriel L. Somlo ha scritto:
> On Thu, Nov 21, 2013 at 07:14:27PM +0100, Paolo Bonzini wrote:
>> > Can you remind us about your DSDT modifications?  It should be possible
>> > to patch the HPET and applesmc bits appropriately from QEMU (or to move
>> > them from the DSDT to an SSDT that is built entirely in QEMU).
>> > 
>> > It actually isn't impossible that Mac OS X would boot just fine with 1.8...
> My current DSDT patch (against QEMU) is enclosed below. The HPET
> basically needs "IRQNoFlags() {2, 8}", which causes XP to bluescreen.

The IRQNoFlags(){2,8} setting makes sense if the general configuration
register of the HPET has bits 0..1=1 (HPET enabled = 1 and HPET legacy
replacement route = 1).

That would be something like

     Field(HPTM, DWordAcc, Lock, Preserve) {
         VEND, 32,
         PRD, 32,
         UNUS, 32
         GCNF, 32
     }

     ...

     Method(_CRS, 0) {
        Store(GCNF, Local0)
        If (LEqual(LAnd(Local0, 3), 3)) {   // Legacy replacement route
             ConcatenateResTemplate(RESP, RESI, Local1)
             Return (Local1)
        } else {
             Return (RESP)
        }
    }

If that doesn't work, there are various choices here...

(1) Does Mac OS work if you add a _PRS with IRQNoFlags and
Memory32Fixed, but leave _CRS as it is?

(2) does it work with -no-hpet?

(3) you could also make that dependent on _OSI("Darwin").  It's unlikely
that Linux and/or Windows expose _OSI("Darwin"), and anyway the BSOD is
only there for Windows XP as I understand it.

> So, I've made it conditional on the SMC STA method returning success
> (0x0B).

That would mean that running Windows XP on "Mac OS X hardware" breaks,
though.

> The SMC node's STA method returns 0x0B unconditionally on real
> hardware. So I was planning on figuring out what's easier in the
> context of the most recent QEMU code base:
> 
>       1. dynamically generating (during qemu runtime initialization)
>        a DSDT entry for SMC with hardcoded 0x0B STA method, whenever
>       "--device isa-applesmc" is present on the qemu command line
> 
> or
> 
>       2. writing a static (compile-time) SMC node but with a slightly
>       smarter _STA method, which returns 0x0B when "--device isa-applesmc"
>       was given on the cmdline, or which returns 0x00 in the absence
>       of "--device isa-applesmc".

Either would work.  See acpi_get_misc_info and patch_ssdt in
hw/i386/acpi-build.c.

I think device-dependent ACPI stuff should become a QOM interface, but
you need not do that.

Paolo