Yet another architecture

[schwidefsky at de dot ibm dot com]

Hi folks,
last week IBM announced a new mainframe: Freeway, zSeries or simply G7. The
most interesting feature is the 64 bit extension.  We have a prototype of
64 bit Linux for this new machine already running. Before we go any further
or publish code I'd like to ask some more or less important questions.
1) The name of the beast. We use the preliminary name s390x at the moment.
I can't say that I like it but I couldn't think of something better. The
project name of the machine is "Freeway", the architecture extension is
called "esame" and in addition s/390 has been renamed to zSeries. How
should we call the configuration name for the 64 bit backend for S/390?
2) How should we integrate this new backend to the glibc? Currently we have
additional "s390x" directories in sysdeps and sysdeps/unix/sysv/linux. We
started with copies from "s390" and modified them.  That differs in spirit
from e.g. sparc who has two subfolders sparc32 and sparc64 in the main
sparc directory. Any preferred method?
3) We took most of the needed 64 bit modifications from ia64. Is there
anything in ia64 which is known to be suboptimal we could avoid?
4) I defined a EM_S390X for the 64 bit binaries. Is there a way I could use
EM_S390 plus an additional check for 64 bit in elf_machine_matches_host? At
the moment elf_machine_matches_host only takes one parameter, couldn't we
add the bit size?

blue skies,
   Martin

Linux/390 Design & Development, IBM Deutschland Entwicklung GmbH
Schönaicherstr. 220, D-71032 Böblingen, Telefon: 49 - (0)7031 - 16-2247
E-Mail: schwidefsky@de.ibm.com

P.S. by the way, glibc 2.1.95 is running on S/390 but make tests reports
three errors (wordexp-test, test-utime & vismain). I'm investigating.