MIPS Creator CI20 patches (again)

[Paul Boddie]

On Wednesday 10. January 2018 00.48.03 Adam Lackorzynski wrote:
> 
> Adding the .global to the asm block makes thread2 a global symbol which
> I'd like not to have here (contrary to L4UTIL_THREAD_FUNC). Just doing
> "static void thread2()" gives warnings because there is no
> implementation. Looks to me that having a function is much better here.
> I'll have a look into this.
> 
> Thanks for investigating this. And also thanks to James for the nice
> explanation of the issue.

I added a patch that works around this problem (l4util-mips-thread.diff) to my 
collection:

http://www.boddie.org.uk/paul/L4Re-Fiasco.OC.html

(Yes, it's the easiest/laziest approach!)

I have also been trying to extend the CI20 (JZ4780) support to the Ben 
NanoNote (JZ4740), but success is still out of my reach in this regard. 
Currently, the NanoNote is refusing to use the serial pins, having done so 
before from Linux (but not currently, which is worrying), but it has made me 
wonder about a few aspects of the UART configuration.

There seems to be a "kernel" UART, but the userspace seems to have the 
configuration details in l4/pkg/bootstrap/server/src/platform for each board. 
Does the kernel somehow delegate the configuration to the bootstrap component 
or is there somewhere in the kernel that needs to be changed for the "kernel" 
UART? It also makes me wonder about how the jdb communications are configured.

Maybe I missed all of this in the documentation, although if I can't get the 
pins to work then it does remain somewhat hypothetical for my circumstances, 
admittedly.

Paul