Re: [Qemu-devel] [Qemu-block] How to generate custom fw paths for IDE devices?

[Mark Cave-Ayland]

On 25/07/18 14:03, Paolo Bonzini wrote:

> It's possible as long as you don't add any members.  You can add a new
> const char* argument to ide_bus_new, and call it from cmd646.
>
> However, another possibility is to implement the FWPathProvider
> interface in the sun4u machine type.  See hw/ppc/spapr.c for an example.

The FWPathProvider approach seems to be working much better, however I'm 
still a bit stuck trying to set the bootindex for the in-built IDE 
interface. Normally I would use -hda for the internal IDE hd and -cdrom 
for the CDROM, but to support bootindex then I need to use -drive.

On PPC macio has 2 IDE interfaces at 0x20000 and 0x21000 and from 
reading the manual I can see that the following works as expected for 
index between 0 and 2:

$ ./qemu-system-ppc -drive 
id=cd,file=MacOS921-macsbug.iso,if=ide,index=0 -nographic -prom-env 
'auto-boot?=false'

Setting index=3 does something a little more strange compared to using 
plain -cdrom:

$ ./qemu-system-ppc -drive 
id=cd,file=MacOS921-macsbug.iso,if=ide,media=cdrom,index=3 -nographic 
-prom-env 'auto-boot?=false'

0 > show-devs

fff8990c /address@hidden/address@hidden/address@hidden (ata)
fff89c98 /address@hidden/address@hidden/address@hidden (ata)
fff8a024 /address@hidden/address@hidden/address@hidden/address@hidden (block)
fff8a4fc 
/address@hidden/address@hidden/address@hidden/address@hidden/address@hidden 
(block)

The issue here seems to be that according to "info qtree" there is 
*always* an ide-cd device plugged into the location equivalent to that 
of -cdrom, and so with the above command QEMU ends up adding a second 
ide-cd device to the ide.1 bus which confuses OpenBIOS. Is this 
deliberate behaviour?

Finally it seems I can't set bootindex with if=ide:

$ ./qemu-system-ppc -drive 
id=cd,file=MacOS921-macsbug.iso,if=ide,index=0  -device 
ide-cd,drive=cd,bootindex=0 -nographic -prom-env 'auto-boot?=false'

qemu-system-ppc: -device ide-cd,drive=cd,bootindex=0: Drive 'cd' is 
already in use because it has been automatically connected to another 
device (did you need 'if=none' in the drive options?)

And if I try if=none as suggested then according to "info qtree" the 
drive never gets attached to the in-built ide.0 bus in the first place:

$ ./qemu-system-ppc -drive 
id=cd,file=MacOS921-macsbug.iso,if=none,index=0  -device 
ide-cd,drive=cd,bootindex=0 -nographic -prom-env 'auto-boot?=false'

I'm sure that I'm missing something really obvious here related to 
in-built devices but I can't quite see it at the moment...


ATB,

Mark.