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

[Programmingkid]

On Feb 9, 2016, at 11:16 AM, BALATON Zoltan wrote:

> On Tue, 9 Feb 2016, Programmingkid wrote:
>> I was thinking about this and what Mark told me should definitely be applied. We are building a emulator as opposed to a simulator. A simulator will have almost all variables as close as possible to the real thing. With an emulator we are allowed to make changes as long as these changes work. So we may not need to know what the PowerMac3,1 has in its escc/ch-a node.
> 
> Considering that you are trying to run Mac OS versions written by the same company that produced the hardware with only their hardware in mind, I would not be surprised if the code has some assumptions as it knows what to expect. So to run it you may need to make the emulation sufficiently close to real hardware. You might be able to get away with differences but it may be easier to just follow what's on the real hardware instead which is known to work with the software instead of finding out how Mac OS works without access to source and trying to make it run on some fictious hardware it was never intended to be running on. So I think knowing how the real hardware looks is definitely helpful in this case even if we don't want to make a one to one simulation of it.
> 
> In this case we should probably emulate the serial port close enough with DMA support as the OS seems to exepct that to work but we can probably get away by not emulating the modem connected to that port in the real hardware. But we'll see if the OS is happy if it can't find the modem.

If it does turn out we need modem support in QEMU, emulating enough of a hayes compatible modem to fool Mac OS 9 into thinking it is real might not be too hard to do.