The Device Modeling Language (DML) is a domain-specific language for writing fast functional or transaction-level device models for virtual platforms. DML provides high-level abstractions suitable for functional device models, including constructs like register banks, registers, bit fields, event posting, interfaces between models, and logging. DML code is compiled by the DML Compiler (DMLC), producing C code with API calls tailored for a particular simulator.
Currently, the compiler supports building models for the Intel® Simics® simulator, but other back-ends may be added in the future.
To build DMLC, you need to have a Simics simulator installation and a Simics project set up.
If you do not already have a Simics simulator installation or access to the Simics simulator via commercial channels, install the Public Release of the Intel Simics simulator and create a Simics project (automatic in the default installation flow).
In your Simics project, check out the DML repository into the modules/dmlc
directory. At the top-level of the project, do make dmlc
(or bin\make dmlc on Windows).
To run the unit tests provided with DMLC, run make test-dmlc or
bin/test-runner --suite modules/dmlc/test from the top-level
of the project.
The following environment variables are handy when developing DMLC. If you work
regularly with a locally built DMLC, then consider setting the variables
DMLC_DIR T126_JOBS, DMLC_PATHSUBST and PY_SYMLINKS in your
.bashrc. Remaining variables are better to only enable when needed.
After building DMLC, you need to set DMLC_DIR to <your-project>/<hosttype>/bin
in subsequent invocations of make in order to build devices with the locally
build compiler. <hosttype> is either linux64 or win64 depending on your
host type.
When set, the given number of tests are run in parallel.
The DMLC build copies a few DML library files, e.g. dml-builtins.dml, into
<hosttype>/bin. When a compile error happens, error messages will normally point
to this copy rather than the source. By setting DMLC_PATHSUBST to
<hosttype>/bin/dml=modules/dmlc/lib, error messages will be rewritten to point
to the source file instead. <hosttype> is either linux64 or win64
depending on your host type.
When set to 1, make dmlc will symlink Python files instead of copying
them. This has two effects: Python tracebacks will bring you to the source file
in the repository, and you don't need to re-run make after editing Python
files.
When set to 1, unexpected exceptions in the compiler are echoed to
stderr. The default is to hide tracebacks in a file dmlc-error.log.
Override the default compiler in unit tests.
When set, DMLC does self-profiling and writes the profile to a .prof file.
When set, DMLC emits a .tar.xz archive containing all DML source files,
packaged on a form that can be compiled standalone. This is useful when a DML
problem appears within a complex build environment, and you want to reproduce
the problem in isolation. In the created archive, all DML files are located in
the same directory (either top level or under a series of subdirectories called
_), and relative imports are handled by also including symlinks in the
archive. On Windows, DMLC is sometimes unable to resolve these symlinks
correctly; for this reason, it is recommended that the archive is only
extracted and compiled on Linux.
When set, DMLC outputs a file ending with -size-stats.json, which shows code
generation statistics useful to reduce generated code size and increase compile
speed. The file lists how much C code is generated for each DML method. The
output is a list of triples [tot_size, location, num], where tot_size is
the total number of bytes of C code generated from one method declaration,
num is how many times C code was generated from this declaration (because it
was expanded by a template), and location is the source location of the
declaration.
An entry with a large tot_size and a large num can be reduced by declaring
the method as shared; this should roughly divide the size by num. An entry
with large tot_size with num equals 1 usually means the method is dominated
by a construct like #foreach or #select, and can be reduced by breaking out
the loop body into a separate method, or by otherwise reworking the loop into
some other construct like foreach.
Note that the statistics only includes code directly generated from method declarations; the total code size includes much more. One megabyte of code size from method declarations usually contributes with a few seconds of compile time.
