CPM2 early console

Kalle Pokki kalle.pokki at iki.fi
Wed Sep 28 06:35:13 EST 2005

Dan Malek wrote:

> On Sep 27, 2005, at 10:11 AM, Kalle Pokki wrote:
>> Any ideas what can set the bootmem memory as cached?
> All of memory is always cached on 82xx.  Which is fine
> since the cache controller keeps the processor core
> and peripherals coherent in hardware.

OK. Then the question really is why isn't the cache controller enforcing 
coherency between the G2_LE core and the CPM. While trying to debug the 
console driver I wrote a really simple SCC driver separated from the 
rest of the kernel in order to have a usable debug printf. And I 
couldn't get any buffers printed through the SCC until I started to use 
buffers in DPRAM. The CPM just didn't see anything I wrote to the 
buffers. The same thing seems to bother at least the console driver and 
the FCC ethernet driver (though they don't work at all for me at the 

I think it is obvious I have misconfigured something, but at this point 
I am not even sure if it is something I should have initialised in the 
boot loader.

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