Re: pci_mapreg_map and BAR from `Bus space tutorial'

[Rocky Hotas <rockyhotas%firemail.cc@localhost>]

Hello Radoslaw,

On giu 11  1:02, Radoslaw Kujawa wrote:

> It seems that in 2018 cobalt port was switched to common MIPS bus space
> implementation. As a part of this implementation, it started to be more
> strict about verification of addresses used by device during bus_space_map.
[...] 
> Please try the attached gxemul patch.

Thank you so much for this message and the previous ones. Even if I do not
have the necessary knowledge, your comments gave several clarifications.

Also, thanks to Martin for mentioning you and for all his help.

Yes, the 2012 version of gxemul apparently can't compile due to those
warnings treated as errors. So, I tried to figure out what modifications
you made to it (not as many; they can be found through a simple recursive
grep) and applied them to the current gxemul version. This way, I could
use it.

I applied your patch and it works for me the same way. Thanks!

As a sidenote: I found your bus_space_tutorial very useful, the only one
available about this topic. For this problem, I suspended it at slide
47 of your pdf.
My intention is to follow it entirely, and then to elaborate and expend
it (adding comments, citations from the manpages), in order to keep a
useful and up-to-date introduction for a newbie. Would you agree?

I hope to be able to follow the remainder of the tutorial by my own. But
if some other problem could arise, can I contact you in future?
Obviously only if and when strictly necessary. 

In the meanwhile, thanks a lot for your time.

Bye!

Rocky


P.S.
I don't know if it's relevant, but something weird instead happens if I
try to write 0xFFFFFFFF in the faa BAR.
Before your patch, after the write, the BAR provided the value
0x0000FFF0: I was expecting 0xFFFFFFF0.
After your patch, and after writing 0xFFFFFFFF, BAR showed an even weirder
value: 0x000FFFFF. I used pcictl(8) for these operations. However, it all
seems to work from the dmesg, so maybe they are due to the fact that
this PCI device is not real.