Impressions of IBMs Linux/390

[Florian Lohoff]

Hi,
ein paar nette impressions von IBMs Linux/390 ...

Wir bauen uns einen Compiler und das dazugehoerige OS

-------------
IBM's S/390 architecture
CONFIG_ARCH_S390
  Select this option, if you want to run the Kernel on one of IBM's
  mainframes of the S/390 generation. You should have installed the
  s390-compiler released by IBM (based on gcc-2.95.1) before.
----------------


--------------
In order to not introduce a new I/O concept to the common Linux code,
Linux/390 preserves the IRQ concept and semantically maps the ESA/390
subchannels to Linux as IRQs. This allows Linux/390 to support up to 64k
different IRQs, uniquely representig a single device each.
---------------

cat /proc/interrupts | wc -l
46088

:)

Math emulator
------------------
/*
 *  arch/s390/kernel/mathemu.c
 *
 *  S390 version
 *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
 *    Author(s): Martin Schwidefsky (schwidefsky at de.ibm.com),
 *
 * 'mathemu.c' handles IEEE instructions on a S390 processor
 * that does not have the IEEE fpu
 */
------------------



SMP Support
--------------------------------------------------
/*
 *  arch/s390/kernel/smp.c
 *
 *  S390 version
 *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
 *    Author(s): Denis Joseph Barrow (djbarrow at de.ibm.com,barrow_dj at yahoo.com),
 *               Martin Schwidefsky (schwidefsky at de.ibm.com)
 *
 *  based on other smp stuff by 
 *    (c) 1995 Alan Cox, CymruNET Ltd  <alan at cymru.net>
 *    (c) 1998 Ingo Molnar
 *
 * We work with logical cpu numbering everywhere we can. The only
 * functions using the real cpu address (got from STAP) are the sigp
 * functions. For all other functions we use the identity mapping.
 * That means that cpu_number_map[i] == i for every cpu. cpu_number_map is
 * used e.g. to find the idle task belonging to a logical cpu. Every array
 * in the kernel is sorted by the logical cpu number and not by the physical
 * one which is causing all the confusion with __cpu_logical_map and
 * cpu_number_map in other architectures.
 */
--------------------------------------------------


Weiss jemand was CTC und IUCV Network interfaces sind ?

----------------------------
if [ "$CONFIG_NET" = "y" ]; then
  mainmenu_option next_comment
  comment 'S/390 Network device support'

  bool 'Network device support' CONFIG_NETDEVICES
  if [ "$CONFIG_NETDEVICES" = "y" ]; then
    menu_option next_comment
    comment 'S390 Network devices'
    bool 'CTC device support' CONFIG_CTC
    bool 'IUCV device support (VM only)' CONFIG_IUCV
    tristate 'Dummy net driver support' CONFIG_DUMMY
    bool 'Ethernet (10 or 100Mbit)' CONFIG_NET_ETHERNET
    bool 'Token Ring driver support' CONFIG_TR
  fi
  endmenu
fi
----------------------------

Is da wohl was rausgekrochen was nicht haette kriechen duerfen ?

linux/drivers/s391/block/dasd_types.h

----------------
 * IBM CONFIDENTIAL
 * File...........: linux/drivers/s390/block/dasd_types.h
 * Author.........: Holger Smolinski <Holger.Smolinski at de.ibm.com>
 * Created........: 08/31/1999
 * Last Modified..: 09/29/1999
 * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999
----------------

EBCDIC convertierung im Kernel *Evil Grin*

--------------------
/*
 *  arch/s390/kernel/ebcdic.c
 *    ECBDIC -> ASCII, ASCII -> ECBDIC conversion tables.
 *
 *  S390 version
 *    Copyright (C) 1998 IBM Corporation
 *    Author(s): Martin Schwidefsky <schwidefsky at de.ibm.com>
 */
-------------------


Das dingen sieht verdammt sauber und komplett aus - Selbst sachen
wie strace und gdb etc scheinen auf der Schuessel zu laufen - Das sieht
nach einem kompletten userspace aus der irgendwo existiert ...

Flo
-- 
Florian.Lohoff at mediaWays.net                     +49-5241-80-7085
        "Apathy is not the problem, it's the solution"