HEADS UP: Toolchain changes coming soon. (Octeon, n32, n64)

[Juli Mallett]

Over the next day or two I am planning to merge changes to GCC and
binutils adding support for Octeon and the n32 and n64 ABIs, as well
as fixing a couple of bugs in our GCC spec.  Note that the
Octeon-related patches are necessary to support the Cavium Octeon
Simple Executive, which I am planning to import after these changes
have been committed, which will be terribly helpful for the Octeon
port, in particular a new network driver and hopefully soon crypto and
PCI support.

If you have any questions or comments please get in touch with me.
The contents of the patch may shift some before commit as I do testing
on a wider variety of platforms.

The full patch to GCC and binutils is at this URL, and I have
reproduced the description below:

http://people.freebsd.org/~jmallett/mips-toolchain.diff

o) Add TARGET_ABI to the MIPS toolchain build process.  This sets the
default ABI to one of o32, n32 or n64.  If it is not set, o32 is
assumed as that is the current default.
o) Set the default GCC cpu type to any specified TARGET_CPUTYPE.  This
is necessary to have a working "cc" if e.g. mips64 is specified, as
binutils will refuse to link objects using different ISAs in some
cases.
o) Add support for n32 and n64 ABIs to binutils and GCC.
o) Add additional required libgcc2 stubs for n32 and n64.
o) Add support for the "mips64r2" architecture to GCC.  Add the "octeon"
o) When static linking, wrap default libraries in --start-group and
--end-group.  This is required for static linking to work on n64 with
the interdependencies between libraries there.  This is what other
OSes that support n64 seem to do, as well.
o) Fix our GCC spec to define __mips64 for 64-bit targets, not
__mips64__, the former being what libgcc, etc., check and the latter
seemingly being a misspelling of a hand merge from a Linux spec.
o) When no TARGET_CPUTYPE is specified at build time, make GCC take
the default ISA from the ABI.  Our old defaults were too liberal and
assumed that 64-bit ABIs should default to the MIPS64 ISA and that
32-bit ABIs should default to the MIPS32 ISA, when we are supporting
or will support some systems based on earlier 32-bit and 64-bit ISAs,
most notably MIPS-III.
o) Merge a new opcode file (and support code) from a later version of
binutils and add flags and code necessary to support Octeon-specific
instructions.  This should also make merging opcodes for other modern
architectures easier.

Thanks,
Juli.