Oberon-enhanced-Oberon07-compiler

Enhanced Oberon-07 compiler for the Project Oberon 2013 operating system, including the following features:

• Dynamic heap allocation procedure for fixed-length and open arrays
• Numeric case statement
• Exporting and importing of string constants
• No access to intermediate objects within nested scopes
• Forward references and forward declarations of procedures (experimental feature)
• Module contexts (experimental feature)

Note: The term "Project Oberon 2013" refers to a re-implementation of the original "Project Oberon" on an FPGA development board around 2013, as published at www.projectoberon.com.

Documentation: Enhanced-Oberon07-compiler.pdf

Note: This compiler implements only a subset of the compiler provided in Extended Oberon. In particular, Oberon-2 style type-bound procedures are not implemented (as it would require changing the format of the symbol file).

Instructions for using the enhanced Oberon-07 compiler under Project Oberon 2013

PREREQUISITES: A current version of Project Oberon 2013 (see http://www.projectoberon.com). If you use Extended Oberon (see http://github.com/andreaspirklbauer/Oberon-extended), the functionality is already implemented.

NOTE: If you run Oberon in an emulator (e.g., https://github.com/pdewacht/oberon-risc-emu), you can simply backup your existing S3RISCinstall directory, download the compressed archive S3RISCinstall.tar.gz from this repository to your emulator directory, run the command tar xvzf S3RISCinstall.tar.gz in that directory and then restart the emulator, instead of going through the instructions outlined below.

STEP 1: Build a slightly modified Oberon compiler on your Project Oberon 2013 system

Edit the file ORG.Mod on your original Project Oberon 2013 system and set the following constants to the indicated new values:

 CONST ...
   maxCode = 8400; maxStrx = 3200; ...

Then recompile the modified file of your Project Oberon 2013 compiler (and unload the old one):

 ORP.Compile ORG.Mod/s ~
 System.Free ORTool ORP ORG ~

This step is (unfortunately) necessary since the original Oberon-07 compiler has a tick too restrictive constants. To compile the enhanced Oberon-07 compiler, one needs slightly more space (in the compiler) for both code and string constants.

STEP 2: Download and import the files to build the enhanced Oberon-07 to your system

Download all files from the Sources directory of this repository. Convert the source files to Oberon format (Oberon uses CR as line endings) using the command dos2oberon, also available in this repository (example shown for Linux or MacOS):

 for x in *.Mod ; do ./dos2oberon $x $x ; done

Import the files to your Oberon system. If you use an emulator, click on the PCLink1.Run link in the System.Tool viewer, copy the files to the emulator directory, and execute the following command on the command shell of your host system:

 cd oberon-risc-emu
 for x in *.Mod ; do ./pcreceive.sh $x ; sleep 0.5 ; done

STEP 3: Build the enhanced ("new") Oberon-07 compiler and boot linker/loader on the "old" system

 ORP.Compile ORS.Mod/s ORB.Mod/s ~
 ORP.Compile ORG.Mod/s ORP.Mod/s ~
 ORP.Compile ORL.Mod/s ORTool.Mod/s ~
 System.Free ORTool ORP ORG ORB ORS ORL ~

STEP 4: Use the new toolchain on your original system to rebuild the entire system and compiler

Compile the inner core and load it onto the boot area of the local disk:

 ORP.Compile Kernel.Mod FileDir.Mod Files.Mod Modules.Mod ~    # modules for the "regular" boot file
 ORL.Link Modules ~                                            # generate a pre-linked binary file of the "regular" boot file (Modules.bin)
 ORL.Load Modules.bin ~                                        # load the "regular" boot file onto the boot area of the local disk

Compile the remaining modules of the Oberon system:

 ORP.Compile Input.Mod Display.Mod/s Viewers.Mod/s ~
 ORP.Compile Fonts.Mod/s Texts.Mod/s Oberon.Mod/s ~
 ORP.Compile MenuViewers.Mod/s TextFrames.Mod/s ~
 ORP.Compile System.Mod/s Edit.Mod/s Tools.Mod/s ~

Re-compile the enhanced Oberon-07 compiler itself before (!) restarting the system:

 ORP.Compile ORS.Mod/s ORB.Mod/s ~
 ORP.Compile ORG.Mod/s ORP.Mod/s ~
 ORP.Compile ORL.Mod/s ORX.Mod/s ORTool.Mod/s ~

The last step is necessary because the modified version of your Oberon system uses a different Oberon object file format. If you don't re-compile the compiler before restarting the Oberon system, you won't be able to start it afterwards!

STEP 5: Restart the Oberon system

You are now running a modified Oberon system with an enhanced Oberon-07 compiler. Re-compile any other modules that you may have on your system.