Re: GAS port to PDP-10

[Nick Clifton <nickc at redhat dot com>]

Hi Lars,

: > : I have signed a one-year contract to port GAS (among other things) to
: > : the PDP-10 architecture running the TOPS-20 operating system.  The
: > : PDP-10 is a 36-bit word-addressed machine.  If there's anything I
: > : should have in mind to make this work usable to the developers and
: > : users of GNU binutils, please let me know.
: 
: Do you think supporting a machine here the char/short/int types are
: 9/18/36 bits, and doing binary I/O on files consisting of 9-bit bytes
: will pose a problem?

Yes :-)

You will probably have to treat everything as 64 bits and shift and
mask as necessary.

Which file format will this system be using ?  If it is ELF or COFF
then you will probably not have too much trouble, since it will only
be the contents of the sections that you have to worry about, not the
structure of the files themselves.

If it the file format is something TOPS-20 specific then you will be
in for a lot more work.  BFD does have the concept of an internal
representation of an external file format, and code has to be provided
to convert between the two.  So, provided that it is possible to do
these conversions, without loosing vital information, then it should
be possible to port binutils to the TOPS-20 file format.

Cheers
	Nick