Re: [Qemu-devel] How to make USB work with Mac OS X

[Programmingkid]

On Sep 18, 2015, at 2:33 PM, Alexander Graf wrote:

> 
> 
>> Am 18.09.2015 um 15:55 schrieb Programmingkid <address@hidden>:
>> 
>> 
>>> On Sep 18, 2015, at 2:14 AM, Alexander Graf wrote:
>>> 
>>> 
>>> 
>>>> Am 17.09.2015 um 14:42 schrieb Programmingkid <address@hidden>:
>>>> 
>>>> Is there a way to make USB work with Mac OS X on qemu-system-ppc? I used 
>>>> the -usb option, but mounting a flash drive didn't work. Would you know 
>>>> anything that could help?
>>> 
>>> Nothing of the top of my head. It did work on x86, so maybe the ohci 
>>> emulation is broken? OS9 doesn't boot because of USB breakage in ohci...
>> 
>> Just looked at Cormac's GSOC page. He said Mac OS 9 is attempting to write 
>> to the OHCI's HcDoneHead register. Is there anything stopping us from 
>> changing the HcDoneHead register so that it can be written to? 
> 
> Iirc the problem is deeper...

I think you may be right. 

Do you have any more information on this problem?

> 
>> 
>> My other idea is that the operating system thinks the root hub is made by 
>> Apple. If we changed the device descriptor so that the software thinks it is 
>> made by someone else, then the operating system might use the register 
>> correctly. I'm thinking that Apple made their own root hub that can do 
>> things a standard OHCI USB controller can't do. What are your thoughts?
> 
> I doubt that this is the reason.

I did make a patch that makes the hcDoneHead register writable. I can't say I 
noticed a difference in Mac OS 9 or Mac OS X in QEMU with it.