Re: ARM setup: How to load from flash?

[Toralf Lund <toralf at procaptura dot com>]

> > > Tell gcc you don't want start files linked in.  IIRC, it's
> > > -nostartfiles.
> > >      
[ snip ]

>  
>
> > > Why are you using COFF instead of ELF?
> > >      
> > Well, I'm assuming that it's simpler than ELF, and we're
> > talking about a very plain setup, so ELF might just introduce
> > more complexity without giving me anything extra that I need.
> >    
>
> Perhaps if you're actually putting COFF files in flash and
> "loading" them on the fly, the simpler format would be handy.
>  
Yes, I've been thinking about doing that. I'm not sure it's worth the 
effort even with COFF, though.

>  
>
> > That's not the real reason, though. Actually, it's not even
> > true that I'm "using" COFF. So far, I've just loaded plain
> > binary files and simply started execution from the start of
> > the image.
> >    
>
> That's generally what we embedded people do.  If you're
> converting to binary or hex in the end, it doesn't matter which
> object file format you use, and ELF seems to be the format with
> the best support these days.
>  
Hmm. Maybe I'll try building a gcc-arm-elf one of these days...

>  
>
> > These files are created using objcopy -b binary with COFF
> > files as input, because as I said, I know I'll get the right
> > code at the beginning for COFF (I'm not saying that I know I
> > won't for ELF, though.)
> >    
>
> With either, you can write your linker script and startup code
> to make sure that there is an entry point at the beginning of
> the binary image.
>  
I wasn't sure at fist how I might do that, but of course, an explicit 
filename match in SECTIONS should do the trick.


- Toralf

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