From: hoffman@xdelta.zko.dec.nospam
Sent: Friday, March 17, 2000 2:07 PM
To: Info-VAX@Mvb.Saic.Com
Subject: Re: Callable SDA


In article <4.3.0.20000317115536.01cd2c00@24.8.96.48>, Dan Sugalski <dan@sidhe.org> writes:
:I'd request some, but digging into the docs more makes me think that it 
:wouldn't be that easy, though it would be cool. It'd beat having to write 
:kernel-mode code to spelunk around for stuff. (Like process logical tables 
:and DECThreads info and such) Having a SYS$Evil_Things service with a fixed 
:interface to the mutable internals would be nice...

  We do have tools we euphemistically refer to as sys$peek and sys$poke
  as well as a tool known as BFH (um, "big hammer"), and a remote version
  of SDA (not as interesting now, what with the recent addition of the
  system code debugger capabilities) though this stuff is not part of 
  the standard OpenVMS distribution kit.  (I might see if I can clear
  remote SDA for inclusion onto the freeware or latent into the kit. :-)

:Not a happening thing, I 
:expect, given that all of ten people outside of the Q's VMS labs would 
:*use* it, but still... :)

  What sort of specific things do you want access to?  (Without
  intending to open up the flood gates. :-)

  Here are some relatively recent undocumented and unsupported and
  subject-to-change-without-notice additions made to OpenVMS Alpha:

    SYS$LOADABLE_IMAGES:[SYS$LDR]SYSVER.EXE  

    status = sys$fault_page(address, length, pfc)

    a=f$getsyi("MAIN_MEMORY")  (sys$getsyi, too.)
      (four longwords: total, free, used, and modified memory)

    cpu=F$GETSYI("POTENTIALCPU_CNT")  (sys$getsyi, too.)

  I leave it up to the reader to figure out what these are, and 
  how to use these...

  A supported (and cleaned up) version of the existing exe$getspi 
  call has also made it into the contents of an upcoming OpenVMS 
  release...  Most anything MONITOR can see, this API can get...

 --------------------------- pure personal opinion ---------------------------
   Hoff (Stephen) Hoffman   OpenVMS Engineering   hoffman#xdelta.zko.dec.com