prototype for Verilog-A integration using OSDI and OpenVAF

This initial prototype is capable of performing DC, transient and AC
analysis. Not all features of OSDI are supported yet and there are still
some open questions regarding ngspice integration. However many usecase
already work very well and a large amount of CMC models are supported.
The biggest missing feature right now is noise analysis.

test: test case for diode DC working with SH

test: add transient analysis to osdi_diode test

test: added docu text to osdi_diode test

test: added test case directories

fix: bug in osdi_load

test: small change to netlist

fix: implement DEVunsetup

fix: correct behaviour for MODEINITSMSIG

test: osdi diode enable all analysis modes

removed netlist

ignoring test results

added the build of the diode shared object to the python test script

deleting old stuff and always rebuilding the shared object

added diode_va.c to the repo

preparing CI

Create .gitlab-ci.yml file

(testing) add res, cap and multiple devices test

feat: use osdi command to load files

Previously OSDI shared object files were loaded from fixed directories.
This was unreliable, inconvenient and caused conflicts with XSPICE.

This commit remove the old loading mechanism and instead introduces the
`osdi` command that can load (a list of) osdi object files (like the
codemodel command for XSPICE). A typical usecase will use this as a
precommand in the netlist:

.control
pre_osdi foo.osdi
.endc

If the specified file is a relative path it is first resolved relative
to the parent directory of the netlist. If the osdi command is invoked
from the interactive prompt the file is resolved relative to the current
working directory instead.

This commit also moves osdi from the devices folder to the root src
folder like xspice. This better reflects the role of the code as users
may otherthwise (mistakenly) assume that osdi is just another
handwritten model.

test: update tests to new command

fix: do not ignore first parameter

feat: implement log message callback

fix: don't generate ddt matrix/rhs in DC sweep

fix: missing linker script

update to osdi 0.3

(testing) simplify test cases, fix bug

(testing) multiple devices test improvement

(testig) node collapsing bugfix

test: increase tolerance in tests

feat: update to newest OSDI header

fix: temperature update dt behaviour

fix: ignored models

fix: compilation script

fix: allow hicum/l2 to compile with older c++ compilers

fix: set required compiler flags for osdi

fix: disable x by default

fix: add missing SPICE functions

fix: update diode to latest ngspice version

feat: implement python CMC test runner

doc: Add README_OSDI.md

fix: make testing script work with python version before 3.9

fix: free of undefined local variable

fix: do not calculate time derivative during tran op

update osdi version

fixes for compilation on windows

.gitignore

@@ -86,3 +86,7 @@ src/spicelib/parser/inpptree-parser.c
 src/spicelib/parser/inpptree-parser.h
 # Visual Studio Code user options files
 .vscode/
+
+test_cases/diode/__pycache__/*
+test_cases/diode/test_osdi/*
+test_cases/diode/test_built_in/*

AUTHORS

@@ -74,6 +74,7 @@ Dietmar Warning,
 Michael Widlok,
 Charles D.H. Williams,
 Antony Wilson,
+Pascal Kuthe,
 and many others...
 
 If someone helped in the development and has not been inserted in this list

Dockerfile

@@ -0,0 +1,8 @@
+FROM python:3.10.4-bullseye
+
+# python installation
+RUN apt-get update && apt-get -y install bc bison flex libxaw7 libxaw7-dev libx11-6 libx11-dev libreadline8 libxmu6
+RUN apt-get update && apt-get -y install build-essential libtool gperf libxml2 libxml2-dev libxml-libxml-perl libgd-perl
+RUN apt-get update && apt-get -y install g++ gfortran make cmake libfl-dev libfftw3-dev 
+
+RUN pip install pytest numpy pandas

README_OSDI.md

@@ -0,0 +1,33 @@
+# OSDI implementation for NGSPICE
+
+OSDI (Open Source Device Interface) is a simulator independent device interface, that is used by the OpenVAF compiler.
+Implementing this interface in NGSPICE allows loading Verilog-A models compiled by OpenVAF.
+The interface is fixed and does not require the compiler to know about NGSPICE during compilation.
+NGSPICE also doesn't need to know anything about the compiled models at compilation.
+Therefore, these models can be loaded dynamically at runtime.
+
+To that end the `osdi` command is provided.
+It allows loading a dynamic library conforming to OSDI.
+Example usage: `osdi diode.osdi`.
+
+If used within a netlist the command requires the `pre_` prefix.
+This ensures that the devices are loaded before the netlist is parsed.
+
+Example usage: `pre_osdi diode.osdi`
+
+If a relative path is provided to the `osdi` command in a netlist, it will resolve that path **relative to the netlist**, not relative to current working directory.
+This ensures that netlists can be simulated from any directory
+
+## Build Instructions
+
+To compile NGSPICE with OSDI support ensure that the `--enable-predictor` and `--enable-osdi` flags are used.
+The `compile_linus.sh` file enables these flags by default.
+
+
+## Example/Test Case
+
+A simple handwritten diode can be found in `test_cases/diode/diode.c`.
+In the same directory a script named `test_diode.py` is provided that will compile this model and run some example simulations.
+After the script has finished the compilation result `diode.osdi` and the netlist can then be found in `test_cases/diode/test_osdi`.
+
+

compile_linux.sh

@@ -52,14 +52,14 @@ if test "$1" = "d"; then
   echo "configuring for 64 bit debug"
   echo
 # You may add  --enable-adms to the following command for adding adms generated devices 
-  ../configure --with-x --enable-xspice --enable-cider --with-readline=yes --enable-openmp CFLAGS="-g -m64 -O0 -Wall -Wno-unused-but-set-variable" LDFLAGS="-m64 -g"
+  ../configure --with-x --enable-xspice --enable-cider --enable-predictor --enable-osdi --with-readline=yes --enable-openmp CFLAGS="-g -m64 -O0 -Wall -Wno-unused-but-set-variable" LDFLAGS="-m64 -g"
 else
    cd release
    if [ $? -ne 0 ]; then  echo "cd release failed"; exit 1 ; fi
   echo "configuring for 64 bit release"
   echo
 # You may add  --enable-adms to the following command for adding adms generated devices 
-  ../configure --with-x --enable-xspice --enable-cider --with-readline=yes --enable-openmp --disable-debug CFLAGS="-m64 -O2" LDFLAGS="-m64 -s"
+  ../configure --with-x --enable-xspice --enable-cider --enable-predictor --enable-osdi --with-readline=yes --enable-openmp --disable-debug CFLAGS="-m64 -O2" LDFLAGS="-m64 -s"
 fi
 if [ $? -ne 0 ]; then  echo "../configure failed"; exit 1 ; fi
 

configure.ac

@@ -146,6 +146,10 @@ AC_ARG_ENABLE([oldapps],
 AC_ARG_ENABLE([xspice],
     [AS_HELP_STRING([--enable-xspice], [Enable XSPICE enhancements])])
 
+# --enable-osdi: define OSDI in the code. This is for osdi support
+AC_ARG_ENABLE([osdi],
+    [AS_HELP_STRING([--enable-osdi], [Enable OSDI integration])])
+
 # --enable-cider: define CIDER in the code. This is for CIDER support
 AC_ARG_ENABLE([cider],
     [AS_HELP_STRING([--enable-cider], [Enable CIDER enhancements])])
@@ -1156,7 +1160,18 @@ if test "x$enable_xspice" = xyes; then
     AC_SUBST([VIS_CFLAGS])
 else
     XSPICEINIT="*"
+    if test "x$enable_osdi" = xyes; then\
+        case $host_os in
+            *mingw* | *msys* | *cygwin* | *solaris* )
+                XSPICEDLLIBS=""
+                ;;
+            * )
+                XSPICEDLLIBS="-ldl"
+                ;;
+        esac
+    fi
 fi
+
 AC_SUBST([XSPICEINIT])
 AC_SUBST([XSPICEDLLIBS])
 
@@ -1165,6 +1180,36 @@ AM_CONDITIONAL([XSPICE_WANTED], [test "x$enable_xspice" = xyes])
 AM_CONDITIONAL([SHORT_CHECK_WANTED], [test "x$enable_shortcheck" = xyes])
 
 
+if test "x$enable_osdi" = xyes; then
+    AC_DEFUN([AX_CHECK_COMPILE_FLAG],
+    [AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF
+    AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_[]_AC_LANG_ABBREV[]flags_$4_$1])dnl
+    AC_CACHE_CHECK([whether _AC_LANG compiler accepts $1], CACHEVAR, [
+      ax_check_save_flags=$[]_AC_LANG_PREFIX[]FLAGS
+      _AC_LANG_PREFIX[]FLAGS="$[]_AC_LANG_PREFIX[]FLAGS $4 $1"
+      AC_COMPILE_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])],
+        [AS_VAR_SET(CACHEVAR,[yes])],
+        [AS_VAR_SET(CACHEVAR,[no])])
+      _AC_LANG_PREFIX[]FLAGS=$ax_check_save_flags])
+    AS_VAR_IF(CACHEVAR,yes,
+      [m4_default([$2], :)],
+      [m4_default([$3], :)])
+    AS_VAR_POPDEF([CACHEVAR])dnl
+    ])dnl AX_CHECK_COMPILE_FLAGS
+
+    AX_CHECK_COMPILE_FLAG([-std=c11], [
+      CFLAGS="$CFLAGS -std=c11"
+      LDLAGS="$LDLAGS -std=c11"
+    ], [
+      echo "C compiler cannot compile C11 code"
+      exit -1
+    ])
+    AC_MSG_RESULT([OSDI features included])
+    AC_DEFINE([OSDI], [1], [The OSDI enhancements])
+fi
+
+AM_CONDITIONAL([OSDI_WANTED], [test "x$enable_osdi" = xyes])
+
 # Add CIDER enhancements to ngspice.
 if test "x$enable_cider" = xyes; then
     AC_MSG_RESULT([CIDER features enabled])
@@ -1444,6 +1489,7 @@ AC_CONFIG_FILES([Makefile
                  src/xspice/enh/Makefile
                  src/xspice/ipc/Makefile
                  src/xspice/idn/Makefile
+                 src/osdi/Makefile
                  tests/Makefile
                  tests/bsim1/Makefile
                  tests/bsim2/Makefile

src/Makefile.am

@@ -7,6 +7,10 @@ if XSPICE_WANTED
 SUBDIRS += xspice
 endif
 
+if OSDI_WANTED
+SUBDIRS += osdi
+endif
+
 if CIDER_WANTED
 SUBDIRS += ciderlib
 endif
@@ -97,6 +101,8 @@ DYNAMIC_DEVICELIBS =					\
 	@VLADEV@
 
 
+
+
 ## Build ngspice first:
 
 ## compile the icon:
@@ -116,6 +122,8 @@ ngspice_CPPFLAGS = $(AM_CPPFLAGS) -DSIMULATOR
 if WINGUI
 ngspice_LDFLAGS = -municode $(AM_LDFLAGS)
 ngspice_SOURCES += winmain.c hist_info.c
+else
+ngspice_LDFLAGS = 
 endif
 
 ngspice_LDADD = \
@@ -157,9 +165,9 @@ ngspice_LDADD += \
 	xspice/evt/libevtxsp.la \
 	xspice/enh/libenhxsp.la \
 	xspice/ipc/libipcxsp.la \
-	xspice/idn/libidnxsp.la \
-	@XSPICEDLLIBS@
+	xspice/idn/libidnxsp.la 
 endif
+ngspice_LDADD += @XSPICEDLLIBS@
 
 ngspice_LDADD += \
 	frontend/parser/libparser.la \
@@ -175,6 +183,10 @@ ngspice_LDADD += \
 	ciderlib/support/libcidersuprt.la
 endif
 
+if OSDI_WANTED
+ngspice_LDADD += osdi/libosdi.la 
+endif
+
 ngspice_LDADD += \
 	maths/deriv/libderiv.la \
 	maths/cmaths/libcmaths.la \
@@ -439,9 +451,9 @@ libspice_la_LIBADD += \
 	xspice/evt/libevtxsp.la \
 	xspice/enh/libenhxsp.la \
 	xspice/ipc/libipcxsp.la \
-	xspice/idn/libidnxsp.la \
-	@XSPICEDLLIBS@
+	xspice/idn/libidnxsp.la 
 endif
+libspice_la_LIBADD += @XSPICEDLLIBS@
 
 libspice_la_LIBADD += \
 	frontend/parser/libparser.la \
@@ -457,6 +469,11 @@ libspice_la_LIBADD += \
 	ciderlib/support/libcidersuprt.la
 endif
 
+
+if OSDI_WANTED
+libspice_la_LIBADD += osdi/libosdi.la 
+endif
+
 libspice_la_LIBADD += \
 	maths/deriv/libderiv.la \
 	maths/cmaths/libcmaths.la \
@@ -558,9 +575,9 @@ libngspice_la_LIBADD += \
 	xspice/evt/libevtxsp.la \
 	xspice/enh/libenhxsp.la \
 	xspice/ipc/libipcxsp.la \
-	xspice/idn/libidnxsp.la \
-	@XSPICEDLLIBS@
+	xspice/idn/libidnxsp.la 
 endif
+libngspice_la_LIBADD += @XSPICEDLLIBS@
 
 libngspice_la_LIBADD += \
 	frontend/parser/libparser.la \
@@ -576,6 +593,9 @@ libngspice_la_LIBADD += \
 	ciderlib/support/libcidersuprt.la
 endif
 
+
+libngspice_la_LIBADD += osdi/libosdi.la 
+
 libngspice_la_LIBADD += \
 	maths/deriv/libderiv.la \
 	maths/cmaths/libcmaths.la \

src/frontend/com_dl.c

@@ -18,6 +18,21 @@ void com_codemodel(wordlist *wl)
 }
 #endif
 
+#ifdef OSDI
+void com_osdi(wordlist *wl)
+{
+    wordlist *ww;
+    for (ww = wl; ww; ww = ww->wl_next)
+        if (load_osdi(ww->wl_word)) {
+            fprintf(cp_err, "Error: Library %s couldn't be loaded!\n", ww->wl_word);
+            if (ft_stricterror)
+                controlled_exit(EXIT_BAD);
+         }
+}
+#endif
+
+
+
 
 #ifdef DEVLIB
 void com_use(wordlist *wl)

src/frontend/com_dl.h

@@ -5,6 +5,10 @@
 void com_codemodel(wordlist *wl);
 #endif
 
+#ifdef OSDI
+void com_osdi(wordlist *wl);
+#endif
+
 #ifdef DEVLIB
 void com_use(wordlist *wl);
 #endif

src/frontend/commands.c

@@ -268,6 +268,12 @@ struct comm spcp_coms[] = {
       NULL,
       "library library ... : Loads the code model libraries." } ,
 #endif
+#ifdef OSDI
+    { "osdi", com_osdi, FALSE, TRUE,
+      { 040000, 040000, 040000, 040000 }, E_BEGINNING, 1, LOTS,
+      NULL,
+      "library library ... : Loads a osdi library." } ,
+#endif
 #ifdef DEVLIB
     { "use", com_use, FALSE, TRUE,
       { 040000, 040000, 040000, 040000 }, E_BEGINNING, 1, LOTS,

src/frontend/inp.c

@@ -18,6 +18,7 @@ Author: 1985 Wayne A. Christopher
 #include "ngspice/fteinp.h"
 #include "inp.h"
 
+#include "ngspice/osdiitf.h"
 #include "runcoms.h"
 #include "inpcom.h"
 #include "circuits.h"
@@ -565,7 +566,6 @@ inp_spsource(FILE *fp, bool comfile, char *filename, bool intfile)
     if (fp) {
         cp_vset("inputdir", CP_STRING, dir_name);
     }
-    tfree(dir_name);
 
     /* if nothing came back from inp_readall, e.g. after calling ngspice without parameters,
        just close fp and return to caller */
@@ -740,8 +740,16 @@ inp_spsource(FILE *fp, bool comfile, char *filename, bool intfile)
            before the circuit structure is set up */
         if (pre_controls) {
             pre_controls = wl_reverse(pre_controls);
-            for (wl = pre_controls; wl; wl = wl->wl_next)
+            for (wl = pre_controls; wl; wl = wl->wl_next){
+#ifdef OSDI
+                inputdir = dir_name;
+#endif
                 cp_evloop(wl->wl_word);
+            }
+
+#ifdef OSDI
+            inputdir = NULL;
+#endif
             wl_free(pre_controls);
         }
 
@@ -1108,18 +1116,29 @@ inp_spsource(FILE *fp, bool comfile, char *filename, bool intfile)
            of commands. Thus this is delegated to a function using a third thread, that
            only starts when the background thread has finished (sharedspice.c).*/
 #ifdef SHARED_MODULE
-        for (wl = controls; wl; wl = wl->wl_next)
+        for (wl = controls; wl; wl = wl->wl_next){
+#ifdef OSDI
+            inputdir = dir_name;
+#endif
             if (cp_getvar("controlswait", CP_BOOL, NULL, 0)) {
                 exec_controls(wl_copy(wl));
                 break;
             }
             else
                 cp_evloop(wl->wl_word);
+        }
 #else
-        for (wl = controls; wl; wl = wl->wl_next)
+        for (wl = controls; wl; wl = wl->wl_next){
+#ifdef OSDI
+            inputdir = dir_name;
+#endif
             cp_evloop(wl->wl_word);
+        }
 #endif
         wl_free(controls);
+#ifdef OSDI
+            inputdir = NULL;
+#endif
     }
 
     /* Now reset everything.  Pop the control stack, and fix up the IO
@@ -1131,6 +1150,9 @@ inp_spsource(FILE *fp, bool comfile, char *filename, bool intfile)
     cp_curerr = lasterr;
 
     tfree(tt);
+    tfree(dir_name);
+
+
 
     return 0;
 }