[OpenBIOS] [PATCH] drivers/escc.c: Add slot-names property ch-a node under escc
Programmingkid
programmingkidx at gmail.com
Tue Feb 9 15:47:57 CET 2016
On Feb 9, 2016, at 3:24 AM, Alyssa Milburn wrote:
> On Mon, Feb 08, 2016 at 10:45:42PM -0500, Programmingkid wrote:
>> Mac OS X's AppleSCCSerial kernel extension requires the slot-names property in order to use any serial ports. This patch adds the property.
>>
>> After this patch is applied, the next thing that stops Mac OS X from using the serial port is something having to do with DMA.
>
> Great!
>
> 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.
> Which version of OS X are you using for testing this?
Mac OS 10.2.8 is running as the guest.
>
>> http://www.opensource.apple.com/source/AppleSCCSerial/AppleSCCSerial-126.4.0/PPCSerialPort.cpp
>> In this file the setPortName() function is what does the searching for slot-names.
>>
>> Index: drivers/escc.c
>> ===================================================================
>> --- drivers/escc.c (revision 1378)
>> +++ drivers/escc.c (working copy)
>> @@ -456,6 +456,11 @@
>> NEWWORLD(set_property(dnode, "interrupts",
>> (char *)&props, 3 * sizeof(cell)));
>>
>> + /* The four numbers in front of Modem are needed for AppleSCCSerial
>> + kernel extension compatibility. */
>> + char *names = "0001Modem";
>
> Weird. Is this meant to be \x00\x00\x00\x01Modem? (I see that the OS X code
> you linked is just skipping the first four bytes. And it hardcodes the
> PowerMac1,1 case I switched to for my own testing, heh..!)
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.
>
>> + NEWWORLD(set_property(dnode, "slot-names", names, strlen(names) + 1));
>
> If so, I guess you have to replace the strlen with a hard-coded length.
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.
> (Shouldn't the slot-name only be set to a string for one channel? Maybe it
> doesn't matter?)
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.
> - Alyssa
Thank you very much for reviewing my patch.
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