Re: [Fx2lib-devel] Setupdata at 0xe000

[Daniel O'C. <doc...@gs...>]

On 16/09/2011, at 22:43, Chris McClelland wrote:
> OK I see now. Sorry, I was unaware of the 512 bytes of RAM at 0xe000.
> 
> Your patch jumps through hoops to ensure that unless you set
> DSCR_ADDRSPACE, everything remains exactly as it is today. Is that
> really necessary?

Yes.

> If we just go ahead and change the storage class of the string
> descriptors from "code" to "xdata" in setupdat.c[1] (i.e no preprocessor
> guards), will it conceivably break anything? It looks to me like
> changing it to "xdata" merely gives apps the option of relocating
> DSCR_AREA to 0xe000 (which may be used for "xdata" only, not "code"),
> but with NO downside.
> 
> Or am I missing something?

Hmm I'm not sure, I can't try it declared as __xdata at 0x3e00 because my code is too big :)

> FWIW, I just tried the code->xdata + DSCR_AREA=e000 change on the
> firmware in FPGALink[2] and it works fine.

OK. can you try declaring it as __xdata but still at 0x3e00?

> Also, was your diff from a branch or something? The trunk has string
> descriptors declared like this[1] in setupdat.c:
> 
> extern code WORD dev_dscr;
> extern code WORD dev_qual_dscr;
> extern code WORD highspd_dscr;
> extern code WORD fullspd_dscr;
> extern code WORD dev_strings;
> 
> i.e, s/__code/code/g

Yes, I changed them because my version of sdcc complains that code/xdata/etc is deprecated and you should use __code/__xdata/etc.

See this github pull request..
https://github.com/mulicheng/fx2lib/pull/2/files


> [2] http://www.makestuff.eu/wordpress/?page_id=1400

Nice project :)

--
Daniel O'Connor software and network engineer
for Genesis Software - http://www.gsoft.com.au
"The nice thing about standards is that there
are so many of them to choose from."
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