azonenberg · Nov 4, 2016 · Nov 5, 2016 · Nov 5, 2016 · Nov 7, 2016 · Nov 8, 2016
diff --git a/README → README.md b/README → README.md
@@ -1,26 +1,23 @@
+```
+yosys -- Yosys Open SYnthesis Suite
 
- /-----------------------------------------------------------------------------\
- |                                                                             |
- |  yosys -- Yosys Open SYnthesis Suite                                        |
- |                                                                             |
- |  Copyright (C) 2012 - 2016  Clifford Wolf <clifford@clifford.at>            |
- |                                                                             |
- |  Permission to use, copy, modify, and/or distribute this software for any   |
- |  purpose with or without fee is hereby granted, provided that the above     |
- |  copyright notice and this permission notice appear in all copies.          |
- |                                                                             |
- |  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES   |
- |  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF           |
- |  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR    |
- |  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES     |
- |  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN      |
- |  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF    |
- |  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.             |
- |                                                                             |
- \-----------------------------------------------------------------------------/
+Copyright (C) 2012 - 2016  Clifford Wolf <clifford@clifford.at>
 
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
 
-yosys -- Yosys Open SYnthesis Suite
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+```
+
+
+yosys – Yosys Open SYnthesis Suite
 ===================================
 
 This is a framework for RTL synthesis tools. It currently has
@@ -41,8 +38,7 @@ Web Site
 ========
 
 More information and documentation can be found on the Yosys web site:
-
-	http://www.clifford.at/yosys/
+http://www.clifford.at/yosys/
 
 
 Getting Started
@@ -51,7 +47,7 @@ Getting Started
 You need a C++ compiler with C++11 support (up-to-date CLANG or GCC is
 recommended) and some standard tools such as GNU Flex, GNU Bison, and GNU Make.
 TCL, readline and libffi are optional (see ENABLE_* settings in Makefile).
-Xdot (graphviz) is used by the "show" command in yosys to display schematics.
+Xdot (graphviz) is used by the ``show`` command in yosys to display schematics.
 For example on Ubuntu Linux 16.04 LTS the following commands will install all
 prerequisites for building yosys:
 
@@ -61,9 +57,7 @@ prerequisites for building yosys:
 
 There are also pre-compiled Yosys binary packages for Ubuntu and Win32 as well
 as a source distribution for Visual Studio. Visit the Yosys download page for
-more information:
-
-	http://www.clifford.at/yosys/download.html
+more information: http://www.clifford.at/yosys/download.html
 
 To configure the build system to use a specific compiler, use one of
 
@@ -74,7 +68,7 @@ For other compilers and build configurations it might be
 necessary to make some changes to the config section of the
 Makefile.
 
-	$ vi Makefile             ..or..
+	$ vi Makefile            # ..or..
 	$ vi Makefile.conf
 
 To build Yosys simply type 'make' in this directory.
@@ -93,8 +87,8 @@ a simple synthesis job using the interactive command shell:
 	$ ./yosys
 	yosys>
 
-the command "help" can be used to print a list of all available
-commands and "help <command>" to print details on the specified command:
+the command ``help`` can be used to print a list of all available
+commands and ``help <command>`` to print details on the specified command:
 
 	yosys> help help
 
@@ -110,16 +104,16 @@ elaborate design hierarchy:
 
 	yosys> hierarchy
 
-convert processes ("always" blocks) to netlist elements and perform
+convert processes (``always`` blocks) to netlist elements and perform
 some simple optimizations:
 
 	yosys> proc; opt
 
-display design netlist using xdot:
+display design netlist using ``xdot``:
 
 	yosys> show
 
-the same thing using 'gv' as postscript viewer:
+the same thing using ``gv`` as postscript viewer:
 
 	yosys> show -format ps -viewer gv
 
@@ -171,8 +165,8 @@ The following very basic synthesis script should work well with all designs:
 	techmap; opt
 
 If ABC is enabled in the Yosys build configuration and a cell library is given
-in the liberty file mycells.lib, the following synthesis script will synthesize
-for the given cell library:
+in the liberty file ``mycells.lib``, the following synthesis script will
+synthesize for the given cell library:
 
 	# the high-level stuff
 	hierarchy; proc; fsm; opt; memory; opt
@@ -190,16 +184,17 @@ for the given cell library:
 	clean
 
 If you do not have a liberty file but want to test this synthesis script,
-you can use the file examples/cmos/cmos_cells.lib from the yosys sources.
+you can use the file ``examples/cmos/cmos_cells.lib`` from the yosys sources.
 
 Liberty file downloads for and information about free and open ASIC standard
 cell libraries can be found here:
 
-	http://www.vlsitechnology.org/html/libraries.html
-	http://www.vlsitechnology.org/synopsys/vsclib013.lib
+- http://www.vlsitechnology.org/html/libraries.html
+- http://www.vlsitechnology.org/synopsys/vsclib013.lib
 
-The command "synth" provides a good default synthesis script (see "help synth").
-If possible a synthesis script should borrow from "synth". For example:
+The command ``synth`` provides a good default synthesis script (see
+``help synth``).  If possible a synthesis script should borrow from ``synth``.
+For example:
 
 	# the high-level stuff
 	hierarchy
@@ -224,95 +219,95 @@ for them:
 - Non-synthesizable language features as defined in
 	IEC 62142(E):2005 / IEEE Std. 1364.1(E):2002
 
-- The "tri", "triand", "trior", "wand" and "wor" net types
+- The ``tri``, ``triand``, ``trior``, ``wand`` and ``wor`` net types
 
-- The "config" keyword and library map files
+- The ``config`` keyword and library map files
 
-- The "disable", "primitive" and "specify" statements
+- The ``disable``, ``primitive`` and ``specify`` statements
 
 - Latched logic (is synthesized as logic with feedback loops)
 
 
 Verilog Attributes and non-standard features
 ============================================
 
-- The 'full_case' attribute on case statements is supported
-  (also the non-standard "// synopsys full_case" directive)
+- The ``full_case`` attribute on case statements is supported
+  (also the non-standard ``// synopsys full_case`` directive)
 
-- The 'parallel_case' attribute on case statements is supported
-  (also the non-standard "// synopsys parallel_case" directive)
+- The ``parallel_case`` attribute on case statements is supported
+  (also the non-standard ``// synopsys parallel_case`` directive)
 
-- The "// synopsys translate_off" and "// synopsys translate_on"
-  directives are also supported (but the use of `ifdef .. `endif
+- The ``// synopsys translate_off`` and ``// synopsys translate_on``
+  directives are also supported (but the use of ``` `ifdef .. `endif ```
   is strongly recommended instead).
 
-- The "nomem2reg" attribute on modules or arrays prohibits the
+- The ``nomem2reg`` attribute on modules or arrays prohibits the
   automatic early conversion of arrays to separate registers. This
   is potentially dangerous. Usually the front-end has good reasons
   for converting an array to a list of registers. Prohibiting this
   step will likely result in incorrect synthesis results.
 
-- The "mem2reg" attribute on modules or arrays forces the early
+- The ``mem2reg`` attribute on modules or arrays forces the early
   conversion of arrays to separate registers.
 
-- The "nomeminit" attribute on modules or arrays prohibits the
-  creation of initialized memories. This effectively puts "mem2reg"
-  on all memories that are written to in an "initial" block and
+- The ``nomeminit`` attribute on modules or arrays prohibits the
+  creation of initialized memories. This effectively puts ``mem2reg``
+  on all memories that are written to in an ``initial`` block and
   are not ROMs.
 
-- The "nolatches" attribute on modules or always-blocks
+- The ``nolatches`` attribute on modules or always-blocks
   prohibits the generation of logic-loops for latches. Instead
   all not explicitly assigned values default to x-bits. This does
   not affect clocked storage elements such as flip-flops.
 
-- The "nosync" attribute on registers prohibits the generation of a
+- The ``nosync`` attribute on registers prohibits the generation of a
   storage element. The register itself will always have all bits set
   to 'x' (undefined). The variable may only be used as blocking assigned
   temporary variable within an always block. This is mostly used internally
   by yosys to synthesize Verilog functions and access arrays.
 
-- The "onehot" attribute on wires mark them as onehot state register. This
+- The ``onehot`` attribute on wires mark them as onehot state register. This
   is used for example for memory port sharing and set by the fsm_map pass.
 
-- The "blackbox" attribute on modules is used to mark empty stub modules
+- The ``blackbox`` attribute on modules is used to mark empty stub modules
   that have the same ports as the real thing but do not contain information
   on the internal configuration. This modules are only used by the synthesis
   passes to identify input and output ports of cells. The Verilog backend
   also does not output blackbox modules on default.
 
-- The "keep" attribute on cells and wires is used to mark objects that should
+- The ``keep`` attribute on cells and wires is used to mark objects that should
   never be removed by the optimizer. This is used for example for cells that
   have hidden connections that are not part of the netlist, such as IO pads.
-  Setting the "keep" attribute on a module has the same effect as setting it
+  Setting the ``keep`` attribute on a module has the same effect as setting it
   on all instances of the module.
 
-- The "keep_hierarchy" attribute on cells and modules keeps the "flatten"
+- The ``keep_hierarchy`` attribute on cells and modules keeps the ``flatten``
   command from flattening the indicated cells and modules.
 
-- The "init" attribute on wires is set by the frontend when a register is
-  initialized "FPGA-style" with 'reg foo = val'. It can be used during synthesis
-  to add the necessary reset logic.
+- The ``init`` attribute on wires is set by the frontend when a register is
+  initialized "FPGA-style" with ``reg foo = val``. It can be used during
+  synthesis to add the necessary reset logic.
 
-- The "top" attribute on a module marks this module as the top of the
-  design hierarchy. The "hierarchy" command sets this attribute when called
-  with "-top". Other commands, such as "flatten" and various backends
+- The ``top`` attribute on a module marks this module as the top of the
+  design hierarchy. The ``hierarchy`` command sets this attribute when called
+  with ``-top``. Other commands, such as ``flatten`` and various backends
   use this attribute to determine the top module.
 
-- The "src" attribute is set on cells and wires created by to the string
-  "<hdl-file-name>:<line-number>" by the HDL front-end and is then carried
+- The ``src`` attribute is set on cells and wires created by to the string
+  ``<hdl-file-name>:<line-number>`` by the HDL front-end and is then carried
   through the synthesis. When entities are combined, a new |-separated
   string is created that contains all the string from the original entities.
 
-- In addition to the (* ... *) attribute syntax, yosys supports
-  the non-standard {* ... *} attribute syntax to set default attributes
-  for everything that comes after the {* ... *} statement. (Reset
-  by adding an empty {* *} statement.)
+- In addition to the ``(* ... *)`` attribute syntax, yosys supports
+  the non-standard ``{* ... *}`` attribute syntax to set default attributes
+  for everything that comes after the ``{* ... *}`` statement. (Reset
+  by adding an empty ``{* *}`` statement.)
 
 - In module parameter and port declarations, and cell port and parameter
   lists, a trailing comma is ignored. This simplifies writing verilog code
   generators a bit in some cases.
 
-- Modules can be declared with "module mod_name(...);" (with three dots
+- Modules can be declared with ``module mod_name(...);`` (with three dots
   instead of a list of module ports). With this syntax it is sufficient
   to simply declare a module port as 'input' or 'output' in the module
   body.
@@ -326,7 +321,7 @@ Verilog Attributes and non-standard features
          assign b = 42;
       """
 
-- The attribute "via_celltype" can be used to implement a Verilog task or
+- The attribute ``via_celltype`` can be used to implement a Verilog task or
   function by instantiating the specified cell type. The value is the name
   of the cell type to use. For functions the name of the output port can
   be specified by appending it to the cell type separated by a whitespace.
@@ -354,9 +349,9 @@ Verilog Attributes and non-standard features
       endmodule
 
 - A limited subset of DPI-C functions is supported. The plugin mechanism
-  (see "help plugin") can be used to load .so files with implementations
+  (see ``help plugin``) can be used to load .so files with implementations
   of DPI-C routines. As a non-standard extension it is possible to specify
-  a plugin alias using the "<alias>:" syntax. for example:
+  a plugin alias using the ``<alias>:`` syntax. For example:
 
       module dpitest;
         import "DPI-C" function foo:round = real my_round (real);
@@ -365,54 +360,54 @@ Verilog Attributes and non-standard features
 
       $ yosys -p 'plugin -a foo -i /lib/libm.so; read_verilog dpitest.v'
 
-- Sized constants (the syntax <size>'s?[bodh]<value>) support constant
+- Sized constants (the syntax ``<size>'s?[bodh]<value>``) support constant
   expressions as <size>. If the expression is not a simple identifier, it
-  must be put in parentheses. Examples: WIDTH'd42, (4+2)'b101010
+  must be put in parentheses. Examples: ``WIDTH'd42``, ``(4+2)'b101010``
 
-- The system tasks $finish and $display are supported in initial blocks
+- The system tasks ``$finish`` and ``$display`` are supported in initial blocks
   in an unconditional context (only if/case statements on parameters
   and constant values). The intended use for this is synthesis-time DRC.
 
 
 Non-standard or SystemVerilog features for formal verification
 ==============================================================
 
-- Support for "assert", "assume", and "restrict" is enabled when
-  read_verilog is called with -formal.
+- Support for ``assert``, ``assume``, and ``restrict`` is enabled when
+  ``read_verilog`` is called with ``-formal``.
 
-- The system task $initstate evaluates to 1 in the initial state and
+- The system task ``$initstate`` evaluates to 1 in the initial state and
   to 0 otherwise.
 
-- The system task $anyconst evaluates to any constant value.
+- The system task ``$anyconst`` evaluates to any constant value.
 
-- The system task $anyseq evaluates to any value, possibly a different
+- The system task ``$anyseq`` evaluates to any value, possibly a different
   value in each cycle.
 
-- The SystemVerilog tasks $past, $stable, $rose and $fell are supported
-  in any clocked block.
+- The SystemVerilog tasks ``$past``, ``$stable``, ``$rose`` and ``$fell`` are
+  supported in any clocked block.
 
-- The syntax @($global_clock) can be used to create FFs that have no
+- The syntax ``@($global_clock)`` can be used to create FFs that have no
   explicit clock input ($ff cells).
 
 
 Supported features from SystemVerilog
 =====================================
 
-When read_verilog is called with -sv, it accepts some language features
+When ``read_verilog`` is called with ``-sv``, it accepts some language features
 from SystemVerilog:
 
-- The "assert" statement from SystemVerilog is supported in its most basic
-  form. In module context: "assert property (<expression>);" and within an
-  always block: "assert(<expression>);". It is transformed to a $assert cell.
+- The ``assert`` statement from SystemVerilog is supported in its most basic
+  form. In module context: ``assert property (<expression>);`` and within an
+  always block: ``assert(<expression>);``. It is transformed to a $assert cell.
 
-- The "assume" and "restrict" statements from SystemVerilog are also
-  supported. The same limitations as with the "assert" statement apply.
+- The ``assume`` and ``restrict`` statements from SystemVerilog are also
+  supported. The same limitations as with the ``assert`` statement apply.
 
-- The keywords "always_comb", "always_ff" and "always_latch", "logic" and
-  "bit" are supported.
+- The keywords ``always_comb``, ``always_ff`` and ``always_latch``, ``logic``
+  and ``bit`` are supported.
 
 - SystemVerilog packages are supported. Once a SystemVerilog file is read
-  into a design with "read_verilog", all its packages are available to
+  into a design with ``read_verilog``, all its packages are available to
   SystemVerilog files being read into the same design afterwards.
 
 
@@ -448,4 +443,3 @@ Notes:
 - To run `make manual` you need to have installed yosys with `make install`,
   otherwise it will fail on finding `kernel/yosys.h` while building
   `PRESENTATION_Prog`.
-
diff --git a/backends/firrtl/.gitignore b/backends/firrtl/.gitignore
@@ -0,0 +1,2 @@
+test.fir
+test_out.v
diff --git a/backends/firrtl/Makefile.inc b/backends/firrtl/Makefile.inc
@@ -0,0 +1,3 @@
+
+OBJS += backends/firrtl/firrtl.o
+