[OpenBIOS] [PATCH] Use exception vectors from ROM instead of copying them to page zero

[Alexander Graf]

On 28.05.14 22:28, BALATON Zoltan wrote:
> On Wed, 28 May 2014, Mark Cave-Ayland wrote:
>> Just download the latest FreeBSD/NetBSD PPC ISO releases from their 
>> respective websites and try and boot them under QEMU with -M mac99 :) 
>> For one
>
> OK, I've tried FreeBSD and it paniced because it has found an ide 
> controller in the device tree with interrupts set but no interrupt 
> parent. Since QEMU only emulates 2 ata ports of the three the third 
> one should not be there in the device tree. With just this patch:
>
> diff --git a/openbios-devel/drivers/macio.c 
> b/openbios-devel/drivers/macio.c
> index 00d7149..fc08c30 100644
> --- a/openbios-devel/drivers/macio.c
> +++ b/openbios-devel/drivers/macio.c
> @@ -311,7 +312,7 @@ ob_macio_keylargo_init(const char *path, 
> phys_addr_t addr)
>          /* The NewWorld NVRAM is not located in the MacIO device */
>          macio_nvram_init("", 0);
>          escc_init(path, addr);
> -        macio_ide_init(path, addr, 3);
> +        macio_ide_init(path, addr, 2);

If real hardware emulates 3 ports, QEMU should do so as well. If it 
emulates 2, then this patch is correct. Do you have any reference dts 
that can show which one it is?

>          openpic_init(path, addr);
>         ob_unin_init();
>  }
>
> it probably goes further (I have some more ide patches in my tree too 
> that I'll submit later some of which may also be needed) but then 
> crashed when starting to use the VGA card. With -vga none -nographic 
> it goes up to finding its CD but not very useful without a display. 
> (Also QEMU segfaulted with -vga none but without -nographic but I did 
> not investigate that either.) This image seems to break wherever I 
> touch it so using it as a test case would cause more problems than it 
> would help so I gave up on it. I think I'm better off fixing the 
> keyboard under Finnix and use that as that seems to work better on 
> QEMU already.
>
>> You may find the following thread helpful here: 
>> http://comments.gmane.org/gmane.comp.bios.openbios/4992. But again, 
>> you should be able to cross-check with the *BSD sources exactly how 
>> the interrupts are being routed to the CPU in QEMU based upon these 
>> properties which will make life much easier.
>
> I've hoped someone already understands these and can explain it so I 
> don't have to dig up sources.
>
>> And don't forget to make yourself familiar with the IEEE1275 PCI 
>> bindings too: http://www.openfirmware.org/1275/bindings/pci/pci2_1.pdf.
>
> I've already read that document but probably not enough times so I 
> still don't get all of this.

Maybe these references are of some help:

http://git.qemu.org/?p=qemu.git;a=blob;f=hw/ppc/e500.c;h=223bab9eea18dad799041040291b7ad5be7f5e3e;hb=HEAD#l73

http://www.devicetree.org/Device_Tree_Usage#Advanced_Interrupt_Mapping


Alex