Club Amiga de Montreal - CAM/CAM_CD_1.iso/files/255.lha/SetCPU_v1.5/SetCPU.txt

Text File | 1989-06-12 | 16.1 KB | 353 lines

              SetCPU V1.5
        Copyright 1989 by Dave Haynie


    SetCPU V1.5 is my third program designed for identification and
modification of system parameters roughly related to different versions of
the Motorola 68000 family processors.  The program will identify the
various types of processors and coprocessors in any 680x0 system up to
68030/68882 systems.  It also makes an attempt to correctly identify an
incorrectly designed but still functional 68020 system, several of which
are known to exist as Amiga coprocessor boards.  It contains MMU code to
locate kernel ROM in write protected 32 bit ROM, with several optional
patches to that ROM.

    In any case, the syntax of the program is given as follows:

    SetCPU [INST|DATA] [[NO]CACHE|[NO]BURST] [CONFIG n]
           [KICKROM path|dfN:] [VERBOSE] [CARDROM path]
               [[NO]FASTROM [KEYPATCH n] [NOPATCH]] [TRAP n]
               [HEAD] [CHECK 680x0|68851|6888x|MMU|FPU]

where "[]" indicates an optional parameter, "|" indicates a choice of
parameters.  Typing "SetCPU ?" will retrieve this same syntax diagram.
Typing SetCPU alone will result in the SYSTEM configuration being
send to the console, my current system returns this:

    SYSTEM: 68030 68882 FASTROM (INST: CACHE NOBURST) (DATA: NOCACHE NOBURST)

This indicates I have a 68030/68882 system, I've previously installed the
FASTROM translation, and my instruction cache is turned on (done by AmigaOS
V1.2 or V1.3).  Note that any parameters that don't make sense to the real
system configuration, such as asking to modify the data cache on a 68020
system or install the FASTROM translation on a 68000 system are just ignored.

[0] DISTRIBUTION

    This program may be distributed by any means as long as there are
no charges specifically for the program.  Charges for downloading from
electronic BBS systems, or charges for copying and media for freely
redistributable software libraries are certainly permissible.  Permission
for any commercial distributions are negotiable; please contact me
(eg, the author) if you're interested.

[1] CPU IDENTIFICATION

    There are two basic types of functions performed by SetCPU.  The
first of these is CPU system identification and cache control.  SetCPU will
tell about the type of CPU setup in your machine, which consists of the CPU
itself and sometimes FPU or MMU coprocessors.  If the CPU supports caches,
SetCPU will let you switch these caches, and associated cache line burst mode,
on and off.  Finally, SetCPU can be used in a Startup-Sequence or other script
to make decisions based on the system that's running.  This is quite useful
with accelerator cards like the Commodore A2620 that let you boot the machine
with either 68020 or 68000 in charge.  The individual CPU group commands are
given below in detail:

[NO]CACHE
    This command will switch on or off 68020 and 68030 caches.  If not
    qualified, it'll act on both instruction and data caches of the 68030.

[NO]BURST
    This command will switch on or off the burst cache line fill request
    of the 68030.  If not qualified, it'll act on both instruction and
    data caches.

INST
    This qualifies a CACHE or BURST operation to restrict it's application
    to the instruction cache only.

DATA
    This qualifies a CACHE or BURST operation to restrict it's application
    to the data cache only.

CHECK
    This option lets you check for the existence of a particular CPU
    system component in a script.  It works like this:

        SetCPU CHECK 68020
        If WARN
            echo "No 68020 here!"
        Else
            echo "Sho nuff got a 68020 here!"
        Endif

    The arguments to CHECK can be any of:

        68000    Matches the obvious
        68010    "
        68020    "
        68030    "
        68851    "
        68881    "
        68882    "
        FPU    Matches 68881 or 68882
        MMU    Matches 68851 or 68030

If any cache parameter doesn't apply to the system in use, it'll just be
ignored.  Use the data cache and all burst modes with caution.  Some
68030 systems aren't designed to correctly support the data cache, so
switching it on may cause an instant system crash.  Even on systems that
correctly support the 68030 data cache, some device drivers, especially
those for DMA devices, may not work properly with the data cache enabled.
You may wish to check with your system vendors to make sure before using
the data cache in your standard system setup.

    SetCPU may report a "FPU Logic Error" on certain 68020 systems.
This is indicating a hardware problem with that board's floating point
coprocessor decoding, which results in the FPU responding to the MMU
addresses as well as it's own.  SetCPU knows how to handle such a board,
but future software using the MMU may not, so it's a good idea to report
this problem to the board vendor for repair.


[2] ROM TRANSLATIONS

    The second thing that SetCPU V1.5 manages are ROM translations.
Using the MMU on systems so equipped, it can locate the Kernel ROM in the
much faster 32 bit wide memory provided on many 32 bit systems.  It can
also boot a ROM based system with an alternate version of KickStart.
Most of the options here relate to MMU translation setup and various
modifications of the basic translation premise.

    As of this release, SetCPU's MMU configurations will support
memory outside of the 68000's 24 bit address space, when it's present.
In order for such memory to be recognized by SetCPU, it must be linked
into the system free memory pool via AddMem (or any equivalent program)
before SetCPU has been run.  SetCPU will only build MMU tables large
enough to handle the amount of RAM at the time the MMU table is built,
so running AddMem after an MMU translation is in effect can cause a
problem.  Since the KICKROM table is built before rebooting, use of
AddMem won't be a problem after rebooting on the new OS, providing the
same memory is added that was around when the KICKROM operation was
started.

[NO]FASTROM
    This activates the FASTROM translation on or off an MMU equipped
    system.  When switching on, it first allocates 256K of memory for
    the ROM image, then at least 512 bytes of memory for the MMU table.
    It copies the ROM into the image area, then applies the translation
    by pointing the MMU at the table and activating it.  The NOFASTROM
    option will switch off the MMU and reclaim the memory used for the
    ROM image and MMU table.  If any other program set up the MMU
    for something, this could be a very bad thing to do.  In general,
    until there's some level of OS support for the MMU in Amiga systems,
    you're really safe using only one MMU tool at a time.  If you have
    an A2620 system, this option will always get 32 bit memory for you,
    if not, you'll have to make sure that your 32 bit memory is the
    first MEMF_FAST memory in the memory list for it to be used for the
    ROM image.  Also, that ROM image will be allocated as far back on
    that memory list as possible unless the "HEAD" option is specified.
    The SetCPU "SYSTEM" line will report this setup as a "FASTROM" setup.

Suboptions are:

    KEYPATCH n
        This will patch the keyboard scanning routine for machines
        that have Cherry keyboards (small function keys).  The "n"
        parameter allows a variable delay between 1 and 100 to be
        specified; the delay depends on the keyboard, but should
        be pretty independent of CPU speed.

    NOPATCH
        This prevents the normal ROM patches from being applied.
        Normally the Workbench screen message is patched to say
        "FastBench", as a visual indication that the FastROM
        routines are installed.  These patches are currently only
        available under the release 1.3 Kernel.

CARDROM path

    When used in conjunction with the FASTROM option, this allows ROMs
    from expansion cards to be located in fast memory as well.  The
    path should reference a file containing lists of expansion cards
    that should be translated if found.  It's necessary to read this
    from a user-defined file, rather than from the expansion environment
    itself, since an expansion device's ROM could be located close to
    that device's registers; there's no way for SetCPU to know it's
    safe to translate a card ROM image unless you tell it.  On my system
    I read a file called CardROMList, which currently contains the single
    line:

        0x202 0x01 0x10000 0x8000 0x4000 CBM_2090A_Disk_Controller

    All the numbers given are in C language hex format.  The parameters
    are, in order, the device's manufacturer code, product code, the
    device's size (in bytes), the ROM's offset from the configured board's
    base address (in bytes), and the size of the ROM area to be
    translated (in bytes).  The final item is text string to identify
    the device; this'll be displayed by the VERBOSE option if the ROM
    translation does in fact take place.  The "_" characters in the
    name will be translated to " " characters.

HEAD
    This option causes the SetCPU memory allocator to attempt memory
    allocation for it's translated objects from the start of 32 bit
    memory instead from the end, as it usually does.  Allocation from
    the end usually results in less fragmentation than from the start
    (due to the alignment restrictions of MMU objects), though this
    option is useful when dealing with merged memory lists.  It is
    ignored when the ROM image and tables are in chip/$00C00000 memory.

KICKROM path|dfN:

    The KickROM option allows the system to be restarted with an
    alternate ROM image.  This can be from a KickStart disk in a
    specified floppy drive, or from a given file name.  If the
    ROM image is accessible, this command will cause the system to
    be immediately rebooted into the new OS.  Note that pre-1.3
    versions of the Amiga operating system will probably have some
    trouble with expansion cards, especially autoboot cards.  For
    that reason there's the CONFIG 0 option, which is explained
    later.

    The KICKROM command will reboot the machine with the new OS, but
    that ROM image will be physically located in either memory at
    $00C00000, if it's available, or chip memory, otherwise.  Once the
    new OS has started up, issuing either "SetCPU FASTROM ..." or
    "SetCPU KICKROM..." will cause that image to be moved into fast
    memory, and the slow memory will be given back to the system.  The
    SetCPU "SYSTEM" line will report a 16 bit KickROM image as a
    "SLOWKICK", and a 32 bit KickROM image as a "FASTKICK".  A machine
    running from a SLOWKICK kernel can't be re-KICKROMed, but can be
    from a FASTKICK kernel.

CONFIG n
    This option controls if and how expansion devices are recognized on
    a KICKROM boot.  At the default configuration level, level 2, the
    expansion cards are left alone, allowing the new Kernel to try and
    configure them.  Since some older operating system will choke on
    autoboot devices, this option will allow suppression of them for the
    rebooting process.  When requesting a KICKROM boot, a CONFIG level
    of 0 or 1 will prevent the devices from being recoginzed.

    Once rebooted in the new OS, moving from a SLOW    to a FAST Kick image,
    as described above, the CONFIG status will be honored.  If the
    devices weren't suppressed, nothing special happens.  If they were,
    they'll stay suppressed, and you very likely won't have the memory
    to support a FAST Kick image.  Specifying a CONFIG level of 2 at
    this point will attempt to configure the devices without autobooting.
    At level 1, the devices will be made visable to the system again,
    but nothing will be done with them.

    As of the SetCPU V1.5 Gamma 6 release, CONFIG 0 appears to be
    required with the 1.2 operating system, at least if there's any
    autoboot device, even if you're attempting to move from a slow to
    fast kick image.  The next release will attempt to allow 1.2 to
    configure non-autobooting devices at this point.

TRAP n
    This option controls the level of error trapping handled for
    you by the SetCPU system.  The numeric parameter is actually
    optional for compatibility with SetCPU V1.4.  If no TRAP is
    specified, the default level 2 is enacted.  If the TRAP command is
    given without a parameter, trap level 0 will be setup.

    Trap level 0 causes the MMU to look at all 32 bits of address;
    access to any memory outside of the 24 bit space will result
    in an exception, which if unhandled, results in a GURU 2.  Trap
    level 1 will set up the MMU to only look at 24 bits of address space.
    Trap level 2 works like level 1, but additionally sets up a trap
    handler for the Bus Error exception (which usually surfaces as a
    GURU #2).  For normal operation (eg, running other people's code),
    Trap level 2 is probably what you want.  For final testing of your
    own code, levels 0 or 1 can catch things which would go unnoticed
    on a 68000 machine, such as writing to ROM space or out of the 24
    bit address space.

    The exception handler used for level 2 trapping catches things like
    writes to protected areas of memory.  It just tells the bus machine
    not to complete the write, and signals no error.  There's a slight
    chance that this won't be enough repair for a program doing something
    really outlandish -- at that point, running at level 1 will let the
    GURU happen, which might help if you're debugging your own code.
    Other that that, there's probably nothing you can do to get such a
    program working with the MMU turned on, other than having it fixed.
    The other thing to consider is that this exception handler could
    conflict with another system-level handler installed by a GOMF-like
    program.  That shouldn't cause a big problem, since you'll the one
    that was installed later, both of which presumably trap the error,
    but it's something to be aware of.

    Under V1.3 and earlier releases, a DOS bug can cause invalid accesses,
    which cause the exception, when running the EndCLI or NewCLI/NewShell
    programs; running at level 1 or 2 will avoid gurus with these commands.

VERBOSE
    This option more fully describes the system translations.


[3] CREDITS

    While this program is an entirely original work, nothing happens in
vaccuum, this one included.  I'd like to mention folks who, directly or
indirectly, helped make this thing happen:

    - Neil Katin, for writing some original MMU code while still working
      at Commodore-Amiga.  His example got me started with SetCPU V1.4,
      and while I never tried the version that supposedly worked a bit
      like my KICKROM option, that nevertheless gave me confidence that
      it could be done.

    - Jez San, for his "KeyHack" program.  First of all, KeyHack served
      to take some of the heat off of SetCPU 1.4 for those folks with
      the older German keyboards.  Secondly, with KeyHack installed on
      my system, I knew where to look for the patch location.

    - Bryce Nesbitt, Andy Finkel, and the other Commodore-Amiga software
      folks, for giving me both the initial and final push toward making
      the KICKROM stuff work.  For about 24 hour I got to be the gating
      factor for both hardware and software efforts.  Fortunately, it
      didn't last longer than that.  Bryce also gave me the secret to
      reasonably CPU-speed independent software timing loops that don't
      count on a living OS.  I shoulda figured that one out myself.

    - The rather numerous lot of beta testers, who during the rather
      long testing period of SetCPU V1.5, found all kinds of horrible
      and stupid screwups.  It should be pretty sound at this point,
      if not absolutely perfect.  Undoubtedly worth the money.

[4] A FINAL NOTE

    I should point out here that much of what SetCPU does may be wrong in
a future release of the OS.  Things like identifying the MMU, CPU, or FPU that
aren't fully done in 1.3 may still work in a future OS release, but if that OS
is correctly identifying the MMU, CPU (eg, 68020 vs. 68030), or FPU (eg, 68881
vs. 68882), SetCPU should be using the OS's opinion of these items, not
testing them itself.  On a more drastic tack, if an OS ever starts using the
MMU, the FASTROM and other MMU code will almost certainly break.  It's the job
of the OS to arbitrate the MMU, and if the OS is doing that, no legal program
would be able to come along and muck with the MMU registers without reeking
havoc on the operating system.

    Finally, if you wish to contact me regarding bug reports, new
releases, contributions of cash or macadamia nuts, or pretty much anything
else, I can be reached at the below addresses.  I expect to at the very
least maintain the



            -Dave Haynie

        Logical Address:
             PLINK:        D-Dave H
             bix:        hazy
             usenet:    {uunet,rutgers}!cbmvax!daveh

        Physical Address (after June 26):

             284 Memorial Drive
             Gibbstown, NJ
             08027