Register Usage

[Richard Earnshaw]

On Wed, 2009-04-29 at 05:14 -0700, John Farmer wrote:
> Hi Richard,
> 
> Applogies if this sounds silly but I am new to the GCC toolchain.
> 
> Are you saying that arm-none-eab is a type of compiler and not a command
> line option? 

Yes, when you build GCC from the sources you get to determine both what
machine you want to target (ARM, MIPS, Sparc, etc) and what sort of
platform will be running on your machine (Linux, Solaris, bare-metal (ie
no OS).  You can find out what configuration was used for your
particular compiler if you invoke GCC with just the -v option.  For
example, a compiler I have here says:

[RWE]$ arm-eabi-gcc -v
Target: arm-eabi
Configured with: /home/rearnsha/gnusrc/gcc-cross/trunk/configure
--prefix=/work/rearnsha/gnu/trunk/testinstall --enable-checking=release
--disable-werror --enable-languages=c,c++ --target=arm-eabi
--with-headers=/home/rearnsha/gnusrc/gcc-cross/trunk/newlib/libc/include
--with-newlib --disable-libmudflap
--with-gmp=/home/rearnsha/gnu/install/x86
Thread model: single
gcc version 4.4.0 20081112 (experimental) (GCC) 

> 
> The GCC tools "as" and "cc1" that I have are part of the development IDE
> (CrossWorks for ARM) that I am using and are based on GCC V4.1.1. 
> 

If your target isn't for the EABI (see above), then I think you'll need
to talk to the CrossWorks people to find out how to get one.

> Would I be correct in thinking that "as" and "cc1" would have been built
> specifically for the ARM CPU? Looking at the --help for these the only CPU
> options shown are for the ARM which presumably suggests that many (non-ARM)
> options have been removed.

Indeed (see above).

R.