Fixed do file line numbers in messages to properly track after nested do command files.
Generalized do file command echoing to always include the do file line number
Fixed SET ON which was broken when SET ON INHERIT and SET ON NOINHERIT was added.
Fixed ON INHERIT behaviors for global ini files.
Added SET QUIET and SET NOQUIET commands
Added -Q flag to DO command file processing which sets quiet mode while that command file executes
Changed generic include file name to simh.ini from simh.rc to be consistent with other include files
Changed generic include file to come from the user HOME or HOMEPATH directory and if not found, the current default directory
Fixed format string used to provide quotes around arguments containing spaces while producing %* expansion.
Fixed return from do_cmd to return the status from the last command executed
It also modifies the HP 2100 and PDP11 multiplexers to add serial support as demonstrations of the capability that, one day, might be extended to all simulators. I have tested the HP support, but I relied on Holger Veit to test the DEC stuff, so I can't guarantee that it works. I also relied on Holger to test under Linux, so the same caveat applies.
The changes needed in the device simulators are relatively small. For example, if you look at the patches for "hp2100_baci.c", you'll note that most of them are documentation changes. The only things of note are:
- an expansion of the TMXR initializer
- additional code in the "attach" routine to try attaching a serial port
if attaching a socket fails
- additional code in the "detach" routine for the same reasons
The HP MPX device (hp2100_mpx.c) needs a tiny bit of additional support from the ATTACH and DETACH commands. Specifically, SCP was modified to set a flag ("sim_unit_ref") to indicate whether ATTACH MPX or ATTACH MPX0 was done, i.e., to differentiate between a device and a unit attach (recall that SCP treats these as both referring to unit 0). This is needed because the socket attaches (logically) to the device, whereas a serial port attaches to a line. Without this flag, the attach routine cannot differentiate between ATTACH MPX and ATTACH MPX0, as the distinction is lost by the time the VM's attach routine is called. This support isn't needed for the HP MUX device because the socket attaches to a different device than the lines do.
MPX also requires a bit more work due to the capability to mix serial and Telnet lines on the same multiplexer (BACI is a single-line terminal device).
The attached PDF contains revisions to the "Writing a Simulator for the SIMH System" publication that documents the additions and changes to the multiplexer library for serial port support. User documentation for serial port support currently exists only in the initial comments in "sim_tmxr.c"; I will add the appropriate text to the "SIMH User's Guide" if we decide to add this to the release version.
Added Message Suppression flag for status values, including providing a -Q option to the RETURN command to return with a message suppressed status
Added Do command file default extension of .sim (from Dave Bryan)
Added -O option to DO command file invocation which causes the caller's ON state and actions to be inherited in the newly called DO command file
Added Command Line expansion to include a %* which expands to the whole set of arguments (%1 ... %9)
Relaxed Command Line argument substitution (delimited by %'s) which cause environment variable lookups to first lookup the literal name provided and if that fails, lookup the name upcased.
Added a SIM_VERIFY special Command Line expansion variable which expands to "-V" when command echoing is active
Added a SIM_MESSAGE special Command Line expansion variable which expands to "-Q" when error message display is suppressed
Added Command Aliasing, which causes the initial token on a command line to be looked up in the environment variable table, and if it exists to substitute the expansion for the initial token.
Changed environment variable defining (with SET ENV variable=value) to always upcase the variable name.
Added SHIFT command which shifts the numbered argument variables %1 ... %9 to the left by one (%1 becomes what was %2, etc.)
Added CALL command which will call a routine (label) in the currently executing command file
Added SET VERIFY and SET NOVERIFY commands which enable or disable DO command echoing
Added SET MESSAGE and SET NOMESSAGE commands which globally enable or disable the display of status messages when commands (or Do Commands) return with unsuccessful status
Added SET ON INHERIT and SET ON NOINHERIT to globally enable inheritance of ON state and actions when DO commands are invoked
Added PROCEED and IGNORE commands which are do nothing but return success. These can be used in specific ON actions to possibly ignore particular return status values
Added DO command file line number to error messages which are displayed while processing DO command files
Expanded the DO command nesting level to 20 to potentially allow for more nesting due to the extensive use of CALL commands are used
- Removed flawed logic which assumed that sim_interval was meaningful when referenced by an asynchronous thread.
- Adjust the event_time of events removed from the asynch queue to account for the average time spent on the queue before the event was noticed by the instruction execution thread.
- Added a sim_activate_notbefore function which specifies an rtime which is the earliest time the event should fire.
- Changed the 'wakeup from idle' logic to force an immediate asynch queue check if the wakeup was not due to a timeout (i.e. it was due to an asynch queue insertion).
- Fixed the descrip.mms to build asynchronous support on AXP and IA64 VMS with kernel threads enabled
The logic here is based on the idea that a restore image contains the memory content for a running simulator, while the attached files contain the disk contents for that simulator. If the disk contents have changed since the memory image was created then the two data sets are likely out of sync and disk details cached in memory (i.e. file system information, storage allocation, etc.) will likely result in corrupted disk structures if they are used.
The default behavior is to fail the restore operation if these inconsistencies are noticed. This sanity check can be overridden if the restore command is invoked with the '-F' switch: sim> restore -F simulator-state.file
Also added logging of all erro messages produced during a restore operation to both stdout and a simulator log file if it is being used.
- Sleep for the observed clock tick size while throttling
- Recompute the throttling wait once every 10 seconds
to account for varying instruction mixes during
different phases of a simulator execution or to
accommodate the presence of other load on the host
system.
- Each of the pre-existing throttling modes (Kcps,
Mcps, and %) all compute the appropriate throttling
interval dynamically. These dynamic computations
assume that 100% of the host CPU is dedicated to
the current simulator during this computation.
This assumption may not always be true and under
certain conditions may never provide a way to
correctly determine the appropriate throttling
wait. An additional throttling mode has been added
which allows the simulator operator to explicitly
state the desired throttling wait parameters.
These are specified by:
SET THROT insts/delay
where 'insts' is the number of instructions to
execute before sleeping for 'delay' milliseconds.
Note: Since NetBSD and OpenBSD are still actively developed operating systems, new versions of
these OSes are moving targets with regard to providing idle detection. At this time, recent versions
of OpenBSD have veered from the traditional OS idle approach taken in the other BSD derived OSes.
Determining a reasonable idle detection pattern does not seem possible for these versions.
I’ve always wanted to have the option to have simulated devices behave
more naturally with respect to I/O operations. By more naturally I
mean that the current simulator model I/O is either polled (for asynchronous
things link Muxes and Network), or it is performed in the middle of some
instruction execution taking possibly many milliseconds (disk and/or tapes).
The existing model creates quite deterministic behavior which helps to debug
and understand issues, but it trades off potential instruction execution
while performing these I/O operations in between instruction execution.
To address this concept (while still retaining the potential advantages of
the original model), I’ve designed an Asynch I/O model extension for simh.
In order to flesh-out and debug this design, I’ve also refactored several
devices to utilize this capability. Please read the attached
0readmeAsynchIO.txt file for concept details about the approach.
In order to make disk devices easy to implement (within or without the
AsynchIO framework), I’ve created a sim_disk.c library which is modeled
on the sim_tape.c library to generalize disk I/O like tape I/O is
generalized in sim_tape.c. This sim_disk.c library now provides that
natural place to implement support for various disk implementation formats
(just like sim_tape support several formats, and one day will be the place
to add direct physical tape access). The current sim_disk library provides
the framework for direct support of 3 different disk formats:
1) standard simh disk format
2) platform specific physical disk access
and 3) platform independent Virtual Disk format.
The Virtual Disk format is an implementation of the format described in
the ”Microsoft Virtual Hard Disk (VHD) Image Format Specification”. The
VHD specification is available for anyone to implement under the "Microsoft
Open Specification Promise" described at
http://www.microsoft.com/interop/osp/default.mspx.
The VHD implementation includes support for:
1) Fixed sized disks
2) Dynamically expanding disks
and 3) Differencing Disks.
Dynamically expanding disks don’t change their “Virtual Size”, but they
don’t consume disk space on the containing storage until the virtual
sectors in the disk are actually written to (i.e. an RA81 or RA92 VHD
with a VMS installed on it may initially only contain 30+ MB of files,
and the resulting VHD will be 30+ MB). The VHD format contains meta data
which describes the virtual device. Amongst this meta data is the simh
device type which the VHD was originally created as. This metadata is
therefore available whenever that VHD is attached to an emulated disk
device in the future so the device type & size can be automatically be
configured.
Sim_disk_attach is used by device emulations to attach a simh/vhd/raw
device to a simulated device. The following simh command switches
are used by the sim_disk_attach API:
-R Attach Read Only.
-E Must Exist (if not specified an attempt to create the
indicated virtual disk will be attempted).
-F Open the indicated disk container in a specific format
(default is to autodetect VHD defaulting to simh if the
indicated container is not a VHD).
-X When creating a VHD, create a fixed sized VHD (vs a
Dynamically expanding one).
-C Create a VHD and copy its contents from another disk
(simh, VHD, or RAW format).
-D Create a Differencing VHD (relative to an already
existing VHD disk)
Examples:
sim> show rq
RQ, address=20001468-2000146B*, no vector, 4 units
RQ0, 159MB, not attached, write enabled, RD54, autosize, SIMH format
RQ1, 159MB, not attached, write enabled, RD54, autosize, SIMH format
RQ2, 159MB, not attached, write enabled, RD54, autosize, SIMH format
RQ3, 409KB, not attached, write enabled, RX50, autosize, SIMH format
sim> atta rq0 RA81.vhd
sim> show rq0
RQ0, 456MB, attached to RA81.vhd, write enabled, RA81, autosize, VHD format
sim> set rq2 ra92
sim> att rq2 -f vhd RA92.vhd
RQ2: creating new file
sim> sho rq2
RQ2, 1505MB, attached to RA92.vhd, write enabled, RA92, autosize, VHD format
sim> ! dir RA92.vhd
Volume in drive H is New Volume
Volume Serial Number is F8DE-510C
Directory of H:\Data
04/14/2011 12:57 PM 5,120 RA92.vhd
1 File(s) 5,120 bytes
0 Dir(s) 3,074,412,544 bytes free
sim> atta rq3 -c RA92-1.vhd RA92.vhd
sim> atta rq3 -c RA92-1.vhd RA92.vhd
RQ3: creating new virtual disk 'RA92-1.vhd'
RQ3: Copied 1505MB. 99% complete.
RQ3: Copied 1505MB. Done.
sim> sh rq3
RQ3, 1505MB, attached to RA92-1.vhd, write enabled, RA92, autosize, VHD format
sim> ! dir RA92*
Volume in drive H is New Volume
Volume Serial Number is F8DE-510C
Directory of H:\Data
04/14/2011 01:12 PM 5,120 RA92-1.vhd
04/14/2011 12:58 PM 5,120 RA92.vhd
2 File(s) 10,240 bytes
0 Dir(s) 3,074,404,352 bytes free
sim> sho rq2
RQ2, 1505MB, not attached, write enabled, RA92, autosize, VHD format
sim> set rq2 ra81
sim> set rq2 noauto
sim> sho rq2
RQ2, 456MB, not attached, write enabled, RA81, noautosize, VHD format
sim> set rq2 format=simh
sim> sho rq2
RQ2, 456MB, not attached, write enabled, RA81, noautosize, SIMH format
sim> atta rq2 -c RA81-Copy.vhd VMS055.dsk
RQ2: creating new virtual disk 'RA81-Copy.vhd'
RQ2: Copied 456MB. 99% complete.
RQ2: Copied 456MB. Done.
sim> sho rq2
RQ2, 456MB, attached to RA81-Copy.vhd, write enabled, RA81, noautosize, VHD format
sim> det rq2
sim> ! dir RA81-Copy.vhd
Volume in drive H is New Volume
Volume Serial Number is F8DE-510C
Directory of H:\Data
04/14/2011 01:22 PM 178,304,512 RA81-Copy.vhd
1 File(s) 178,304,512 bytes
0 Dir(s) 2,896,097,280 bytes free
sim> ! dir VMS055.dsk
Volume in drive H is New Volume
Volume Serial Number is F8DE-510C
Directory of H:\Data
03/08/2011 01:42 PM 403,663,872 VMS055.dsk
1 File(s) 403,663,872 bytes
0 Dir(s) 2,896,097,280 bytes free
sim>
A key capability needed to support simulators running with background
execution is the ability to have a Telnet connected console which isn’t
continuously connected. This feature is called a Buffered Telnet console.
Absolutely nothing changes for someone not interested in using the feature.
However, if someone is interested in the feature, the following SCP
commands are available:
sim> SET CONSOLE TELNET=port ! Unchanged
sim> SET CONSOLE TELNET=BUFFERED{=buffersize} ! buffersize defaults to 32K
sim> SET CONSOLE TELNET=UNBUFFERED ! restores normal behavior
sim> SET CONSOLE TELNET=NOBUFFERED ! synonym for UNBUFFERED
sim> SET CONSOLE TELNET=LOG=logdestination ! enables logging of Telnet session traffic (potentially separate from destination specified by SET CONSOLE LOG=conlogdest)
sim> SET CONSOLE TELNET=NOLOG ! turns off specific logging of Telnet session
sim> SET CONSOLE TELNET=LOG=conlogdest ! turns on logging all console traffic (unless the telnet session logging is also specified).
The logdestinations for any of the logging/debugging commands can
now be:
LOG, DEBUG, STDOUT, STDERR or any file specification (caps are not
required, but these names are reserved to indicate the current
destination of the specified file handles (sim_log, sim_deb,
stdout, stderr).
When a Console Telnet session is Buffered, a simulator will start
(via BOOT CPU or whatever is appropriate for a particular simulator)
without needing to have an active telnet connection. When a Telnet
connection comes along for the telnet port, the contents of the saved
buffer (which wraps on overflow) are presented on the telnet session
as output before session traffic. This allows the connecting telnet
client to see what happened before he connected since the likely
reason he might be connecting to the console of a background
simulator is to troubleshoot unusual behavior.
The current structure has the optional ability to log the Telnet
session separately from the simulator output (i.e. ini file command
execution) is potentially useful when you need to review what the
simulator may have output which may be difficult to find in and
amongst the possibly verbose Operating system console output.
If someone doesn’t use “SET CONSOLE TELNET=LOG=logdestination”,
then the original strategy of logging all output to the target
specified by “SET CONSOLE LOG=logdestination” is preserved. Looking
at the isolated console output might be more interesting if/when
control flow scp commands are ever implemented (ON,GOTO, RETURN, etc.)
The ControlFlow changes fix a potential bug in breakpoint handling
which arguably merely could be “not supported”. That bug is that if
a breakpoint’s actions have multiple actions AND an action early in
the list invokes a do command file, the subsequent pending breakpoint
actions are not performed.
The ControlFlow patch/changes implement the following extensions to
the SCP command language without affecting prior behavior:
GOTO <Label> Command is now available. Labels are lines in which the first non whitespace character is a “:”. The target of a goto is the first matching label in the current do command file which is encountered. Since labels don’t do anything else besides being the targets of goto’s, they could be used to provide comments in do command files, for example (“:: This is a comment”)
SET ON Enables error trapping for currently defined traps (by ON commands)
SET NOON Disables error trapping for currently defined traps (by ON commands)
RETURN Return from the current do command file execution with the status from the last executed command
RETURN <statusvalue> Return from the current do command file execution with the indicated status. Status can be a number or a SCPE_<conditionname> name string.
ON <statusvalue> commandtoprocess{; additionalcommandtoprocess}
Sets the action(s) to take when the specific error status is returned by a command in the currently running do command file. Multiple actions can be specified with each delimited by a semicolon character (just like breakpoint action commands).
ON ERROR commandtoprocess{; additionalcommandtoprocess}
Sets the default action(s) to take when any otherwise unspecified error status is returned by a command in the currently running do command file. Multiple actions can be specified with each delimited by a semicolon character (just like breakpoint action commands).
ON <statusvalue>
ON ERROR Clears the default actions to take when any otherwise unspecified error status is returned by a command in the currently running do command file.
Error traps can be taken for any command which returns a status other
than SCPE_STEP, SCPE_OK, and SCPE_EXIT.
ON Traps can specify any status value from the following list:
NXM, UNATT, IOERR, CSUM, FMT, NOATT, OPENERR, MEM, ARG, STEP,
UNK, RO, INCOMP, STOP, TTIERR, TTOERR, EOF, REL, NOPARAM, ALATT,
TIMER, SIGERR, TTYERR, SUB, NOFNC, UDIS, NORO, INVSW, MISVAL,
2FARG, 2MARG, NXDEV, NXUN, NXREG, NXPAR, NEST, IERR, MTRLNT,
LOST, TTMO, STALL, AFAIL.
These values can be indicated by name or by their internal numeric
value (not recommended).
Interactions with ASSERT command and “DO –e”:
DO –e is equivalent to SET ON, which by itself it equivalent
to “SET ON; ON ERROR RETURN”.
ASSERT failure have several different actions:
If error trapping is not enabled then AFAIL causes exit from the current
do command file.
If error trapping is enabled and an explicit “ON AFAIL” action is defined,
then the specified action is performed.
If error trapping is enabled and no “ON AFAIL” action is defined, then
an AFAIL causes exit from the current do command file.
Other related changes/extensions:
• The “!” command (execute a command on the local OS), now returns
the command’s exit status as the status from the “!” command.
This allows ON conditions to handle error status responses from
OS commands and act as desired.
• Argument substitution has been extended for do command file
execution. The extended argument substitution include
substitution of any program environment variable (referenced by
%ENVVARNAME%) along with dynamic expansion of several pseudo
environment variables:
%DATE% expands to a string of the form: yyyy/mm/dd (i.e. 2011/01/23)
%TIME% expands to a string of the form: hh:mm:ss (i.e. 17:23:44)
%CTIME% expands to a string of the form: www mmm dd hh:mm:ss yyyy
(i.e. Mon Jan 24 08:22:33 2010)
%ENVNAME% expands to a string which has the value of the environment
variable ENVNAME
