Re: Is OpenPIC mandatory for an ofppc-machine?

On Sat, Sep 6, 2014 at 11:40 AM, Frank Wille <[email protected]> wrote:
> Artyom Tarasenko wrote:
>
>> experimenting with Open Firmware for QEMU PReP target.
>> [...]
>> And here it hangs. Saw in some boot logs openpic initialization here.
>> QEMU uses an i8259, can this be the reason?
>
> Does QEMU PReP really emulate OpenFirmware correctly? There must be an
> OFW-tree entry with a name or device_type of "interrupt-controller".
> NetBSD/ofppc works with the Pegasos 2, which is an OpenFirmware machine
> with i8259 PIC. So theoretically it should work.

That's a good news, thank you. Here is my device tree:

ok  show-devs
/dropin-fs
/flash@fff00000
/cpus
/pci
/mmu
/memory@0
/aliases
/options
/openprom
/chosen
/packages
/cpus/PowerPC,603@0
/pci/vga@2
/pci/ide@b,1
/pci/isa@b
/pci/ide@b,1/disk
/pci/isa@b/nvram@i74
/pci/isa@b/rtc@i74
/pci/isa@b/gpio@i3e0
/pci/isa@b/power@i380
/pci/isa@b/8042@i60
/pci/isa@b/fdc@i3f0
/pci/isa@b/parallel@i378
/pci/isa@b/serial@i2f8
/pci/isa@b/serial@i3f8
/pci/isa@b/configuration@i15c
/pci/isa@b/timer@i40
/pci/isa@b/interrupt-controller@i20

ok dev /pci/isa@b/interrupt-controller@i20
ok .properties
built-in
model                    WINB,83C553
reg                      00000001 00000020 00000002
                         00000001 000000a0 00000002
                         00000001 000004d0 00000002
compatible               chrp,iic
                         pci10ad,105-interrupt-controller
                         pci8086,484-interrupt-controller
                         pnpPNP,0
device_type              interrupt-controller
name                     interrupt-controller
#address-cells           00000000
#interrupt-cells         00000002
interrupts               00000000
                         00000000
interrupt-controller
ok

Do you see anything suspicious?

> OFW PIC detection is in src/sys/arch/powerpc/pci/pci_machdep_ofw.c
> genofw_find_ofpics().

Looks like the code (
http://fxr.watson.org/fxr/source/arch/powerpc/pci/pci_machdep_ofw.c?v=NETBSD#L142
)
is expecting just one "compatible" propery. Or do I read it wrong?

Otoh the i8259 is the default. It seems that it should work without
the "interrupt-controller" node at all. I tried removing this node
from the device tree, but I see no visible change in the behavior.

Btw, the boot process seems to be much slower than for NetBSD/prep on
the same machine: writting output looks like an original 300 bod
terminal. Is it normal?

Btw2, we are not emulating OpenFirmware. It is the original
OpenFirmware from FirmWorks which I slightly adjusted for qemu -M
prep.


-- 
Regards,
Artyom Tarasenko

SPARC and PPC PReP under qemu blog: http://tyom.blogspot.com/search/label/qemu