Subject: Re: Broadband adapter again...
To: None <port-dreamcast@netbsd.org>
From: Christos Zoulas <christos@zoulas.com>
List: port-dreamcast
Date: 01/29/2001 03:09:29
In article <200101290237.DAA26357@megalon.idonex.se>,
Marcus Comstedt <marcus@idonex.se> wrote:

Well, you probably need your own bus_space implementation for the
dreamcast...

christos

>Ok, I'm starting to have serious doubts about the splendour of
>bus_space_*.  In the RTK device driver, the chip registers are
>accessed through
>
>   bus_space_read_2(sc->rtk_btag, sc->rtk_bhandle, reg)
>
>This function is defined in <machine/bus.h> as
>
>   u_int16_t
>   bus_space_read_2(tag, bsh, offset)
>   	   bus_space_tag_t tag;
>   	   bus_space_handle_t bsh;
>   	   bus_size_t offset;
>   {
>   	   return bswap16(*(volatile u_int16_t *)(bsh + offset));
>   }
>
>Now, this is not appropriate for the BB adapter.  The byte swapping
>should _not_ be there, and there should also be some additional
>raindancing around the read.  There doesn't seem to be any way to add
>that in a way that is local to the G2 bus though, as the bus_space_tag
>is not used.  (Also, this is in the general sh3 code, where G2 bus
>peculiarities do not belong...)
>
>
>  // Marcus
>
>