[OpenBIOS] [PATCH] drivers/escc.c: Add slot-names property ch-a node under escc

[Mark Cave-Ayland]

On 09/02/16 15:05, Alyssa Milburn wrote:

> On Tue, Feb 09, 2016 at 09:47:57AM -0500, Programmingkid wrote:
>>> You can assign addresses for serial DMA and even OS 9 will try poking at the
>>> dbdma controller, so this is just a question of hooking up the qemu side. I
>>> can try doing this later today if it's useful..
>>
>> It is definitely useful. The ability to run Mac OS 9 in QEMU depends on it.
> 
> After a few days spent poking through the startup process in MacsBug, I'm
> not sure this is true. But I'll hook it up later (if someone else doesn't do
> it first).
> 
>>> Which version of OS X are you using for testing this?
>>
>> Mac OS 10.2.8 is running as the guest. 
> 
> Thanks, I'll see if I can go install 10.2 myself later too..
> 
>> I don't know if your string would work, but you are right that the first four bytes are just skipped. So it doesn't really matter what they are. 
> 
> The first four bytes are the slot bitmask (as a 32-bit BE integer), followed
> by one string per slot (so, one string for each set bit). I don't know
> whether any OS cares about this or not, another thing to look into..

Is the bitmask used to indicate the port presence? If so, could we get
away with just setting it to zero, i.e. there are no ports here so don't
try and access them? Other than that, do OSs check for specific values
of the name string?

>> Is there an issue with strlen()? I thought it was a good idea because it makes the code more self-documenting, meaning you understand what the last argument expects. 
> 
> It fails if you have null bytes in your string (as you would if you encoded
> the integer in it). Otherwise, yes, it's much clearer than using a constant.
> 
>> I don't know. But I do know my G3 iMac's value for this property is this:
>>
>> 00000001
>> Modem
>>
>> The PowerMac3,1 probably has the same value.
> 
> In any case, it makes sense as a value. (Does anyone have an OF dump from a
> PowerMac3,1?)
> 
>> Thank you very much for reviewing my patch. 
> 
> Thank you for the work!
> 
> - Alyssa

ATB,

Mark.