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Re: *Assembler* Error: unrecognized option `-marm920t'


Michael:


The "T" means "thumb", the ARM 16-bit instruction set.

The arm920 option tells gcc to emit 32-bit arm920 instructions.  If
you want arm920 _thumb_ instructions, you add a -thumb.


b.g.



On Sat, Feb 15, 2003 at 07:32:05PM +0100, Michael Keller wrote:
> I have the most recent releases: binutils 2.13.2.1and gcc 3.2.2.
> I now tried with 'arm920', which is accepted by the assembler.
> Unfortunately I have little idea, of how different each of these
> processors are...
> 
> facit: 'arm920t' is a valid flag to gcc, but doesn't seem to be accepted
> even by the newest assembler, - this leaves one to speculate, how it was
> possible to test this flag in the first place? or am I wrong?
> 
> So, do you think, -mcpu=arm920 -mtune=arm920t would be the best
> combination for an ARM920T?
> 
> Thank you,
> michael
> 
> 
> ----- Original Message -----
> From: "Richard Earnshaw" <rearnsha@arm.com>
> To: "mk" <m.keller@stud.unibas.ch>
> Cc: <crossgcc@sources.redhat.com>; <Richard.Earnshaw@arm.com>
> Sent: Saturday, February 15, 2003 4:43 PM
> Subject: Re: *Assembler* Error: unrecognized option `-marm920t'
> 
> 
> > > I built a cross compiler for arm-elf on a linux host. The build
> worked
> > > without error messages. The only (possibly) fancy configuration was
> for
> > > the final gcc build:
> > >
> > > [michael]$ ../gcc-3.2.2/configure
> > > --with-headers=/home/michael/gp32/cross/install/arm-elf/include
> > > --target=$TARGET --prefix=$PREFIX --with-gnu-as --with-gnu-ld
> > > --enable-languages=c,c++
> > >
> > >
> > > Now when I compile some very straightforward C source code (< 20
> lines),
> > > I get an *Assembler* error message:
> > >
> > > [michael]$ arm-elf-gcc -O2 -fomit-frame-pointer -finline-functions
> >
> > -mcpu=arm920t -fno-exceptions -fno-common -fno-builtin -ffreestanding
> > > -mstructure-size-boundary=32 -mno-thumb-interwork -c -Wall -I$INC
> > > gpmain.c
> > >
> > > Assembler messages:
> > > Error: unrecognized option `-marm920t'
> > >
> > > >> Note, that the -mcpu=arm920t switch for the C compiler is
> recognized!
> > >
> > > Can anybody help? Do I have to compile with different options? Or
> > > rebuild gcc with different options?
> > >
> > > Thanks very much in advance.
> > > Michael
> > >
> > >
> >
> > You don't say what version of binutils you are using.  I suspect that
> it
> > is sufficiently old that it doesn't have support for assembling for
> the
> > 920.  Possible solutions to this are:
> >
> > - Upgrade binutils
> > - Target a different processor (try StrongARM for example).
> > - Use -march=armv4t -tune=arm920t (This will give you the same code as
> > with -mcpu=arm920t, but will pass armv4t to the assembler instead
> (it's
> > far more likely to accept that))
> >
> > R.
> >
> 
> 
> ------
> Want more information?  See the CrossGCC FAQ, http://www.objsw.com/CrossGCC/
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> 
-- 
Bill Gatliff
Do you do embedded GNU?  I do!
http://billgatliff.com

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