gnupic: [gnupic] Differend data segment types
Subject:
Re: [gnupic] Differend data segment types
From:
Iain Dooley ####@####.####
Date:
22 May 2005 00:59:53 +0100
Message-Id: <42905A5B.2070005@iaindooley.com>
Peter Onion wrote:
> I'm a little unsure what the various "udata" segment types mean in
> relocation mode, and the gputils manual isn't particularly helpful.
>
> UDATA I understand but what are UDATA_ACS,UDATA_OVR and UDATA_SHR
> for ?
i don't know what SHR or OVR are, but UDATA_ACS is access bank.
> Also, for preformance reasons I'de like to be able to have a data
> segment that I know is in bank 0, but which I can add variables to from
> differnet modules. I can't work out how to do this.
use UDATA_ACS to specify data that must be put in the access bank. if you want to add variables from another module, you just need to declare them external. so the following might be applicable:
extern variable_on_another_bank
myudata udata_acs
somevariable res 1
main:
movf somevariable,W,A
banksel variable_on_another_bank
movf variable_on_another_bank,W
then just make sure you have a module present that defines variable_on_another_bank at link time.
cheers
iain
