Native ELKS Toolchain

ELKS 8086 Toolchain is a work-in-progress project for providing a native ELKS 8086 C compiler toolchain.

This is a fork of the upstream 8086-toolchain, which contains and old NASM version (by Simon Tatham and Julian Hall), and the C86 C compiler by Matthew Brandt, Christoph van Wuellen, Keith and Dave Walker. It was introduced to complete the ELKS native toolchain software by Bruce Evans, Jody Bruchon et al., namely dev86's cpp, ld, ar and as. Make is courtesy of David Given, Carl Eric Codere and Ceriel Jacobs, while disasm (dis88) was originally authored by G. M. Harding. Many improvements and changes by Rafael Diniz and Gregory Haerr for making all the software run on ELKS.

The project currently contains:

• cpp, ld, as and ar from dev86: https://codeberg.org/jbruchon/dev86
• make: https://github.com/davidgiven/ack/tree/default/util/make
• assembler (nasm): https://www.nasm.us/
• C compiler (C86): Also called C68. Manual, Historic versions. See discussion at ghaerr/elks#2112
• disasm: Check README inside the directory

In order to build the ELKS binaries, gcc-ia16 is needed (you can use the one compiled by "build.sh" from ELKS source code) and also OpenWatcom v2 is required.

To build, type "make". Elks binaries will be in "elks-bin" and host binaries in "host-bin". Build should work on any recent Linux or MacOS with OpenWatcom v2 installed (source the OW owsetenv.sh script for setting OpenWatcom environment variables and env.sh from ELKS, or just env.sh from ELKS and wcenv.sh in libc directory of ELKS top-dir, after adjusting the path to OpenWatcom directory).

There is a also a binary distribution available in https://github.com/rafael2k/8086-toolchain/tree/dev/elks-devdisk

Build and Install

To clone this repo, do something like this (adapt to ELKS - build elks first, including the watcom libc - and Watcom paths):

$ cd ~/elks
$ . env.sh
$ . /usr/bin/watcom/owsetenv.sh
$ cd ~/8086-toolchain
$ make clean
$ make

Original 8086 Toolchain README

This is the C-based 8086 toolchain for BYU ECEn 425 (Real Time Operating Systems). This repo also includes an archive of the class website, including all the homework, labs, documentation, and lectures from the class.

The toolchain was taken directly from /ee2/ee425/src/dist on the BYU CAEDM computers.

Disclaimer: For ECEn 425 projects, this may or may not compile exactly the same as the CAEDM machines

Prerequisites to build toolchain:

• Linux:

  • On Debian based systems (Ubuntu, etc.), run the following in your terminal: sudo apt-get install gcc-multilib g++-multilib libc6-dev-i386 lib32ncurses5-dev xterm
  • Tested on Ubuntu 16.04 x86_64, Ubuntu 17.04 x86_64, Ubuntu 17.10, and Ubuntu 22.04 (regular and WSL)

• Mac OS X:

  • Your system will depend on the X11 Window system, which is now called XQuartz. It can be found here.
  • Tested with XQuartz 3.7.7 on Mac OS X Yosemite.

Building on Linux/Mac:

cd into the cloned repo and run make:

$ cd ~/8086-toolchain/
$ make

This will create 5 binaries in the ./bin/ directory:

• c86 - The 8086 compiler
• emu86 - The 8086 emulator
• nasm - The 8086 assembler
• ndisasm - The 8086 disassembler
• ProgramCRT - The terminal program used by emu86 to display Simptris.

If there are any problems, you can try cding into each of the tool directories and running make individually so you can see the warnings/errors more clearly.

To use the binaries from anywhere, see Setting Your Path below.

Setting Your Path

To use the binaries from anywhwere, modify your PATH at the bottom of your ~/.profile or ~/.bashrc (or whatever your shell's startup script is):

# 8086 Toolchain
export PATH="$HOME/8086-toolchain/bin":$PATH

Reload your shell's startup by either closing your shell and reopening it, or using the source command:

source ~/.profile
# Or
source ~/.bashrc

This will add your toolchain bin to PATH in the current terminal.

Common Problems

Linux:

• cdefs not defined: Make sure Linux prereqs are installed
• Parsing errors with Perl generated headers/macros: At some point the files were saved with 'DOS' line endings instead of Unix, so if you see a ^M (Windows carriage return char) that is likely the issue and saving (or overwriting) the file correctly should fix it. Make sure to blow away any generated files.
• If on Ubuntu 17.04 or higher, you may get the following error: xterm: cannot load font '-misc-fixed-medium-r-semicondensed--13-120-75-75-c-60-iso10646-1'. emu86 will still work fine. If you wish to fix the error, you can try following the steps in this form: http://forum.porteus.org/viewtopic.php?f=53&t=1013

Mac:

• cpp does not remove // comments correctly: See Makefile example below, make sure to add -xc++ flag to cpp to remove c99 style comments.

Makefile Example

lab1.bin:       lab1final.s
                nasm lab1final.s -o lab1.bin -l lab1.lst  # Step 4, Assemble

lab1final.s:    clib.S lab1asm.S lab1.s
                cat clib.S lab1asm.S lab1.s > lab1final.s # Step 3, Concatenate

lab1.s:         lab1.c
                cpp -xc++ lab1.c lab1.i    # Step 1, Preprocess
                c86 -g lab1.i lab1.s       # Step 2, Compile

clean:
                rm lab1.bin lab1.lst lab1final.s lab1.s lab1.i

test:
                emu86 lab1.bin

Makefile error: If you copy this directly and paste into a Makefile, the tabs will often be converted to spaces. You will get a "Missing separator" error from make. Just replace the indentions with two tabs and it should work.

Website

The ECEn 425 website is stored in directory website/ and contains lab instructions, 8086 resources, homework assignments, and class slides.

Browsing the website

The class website is currently hosted via GitHub pages here. The original site is also available on Wayback Machine.

Optionally, you can browse all the files locally by pointing your web broswer to the file website/index.html, and all the links should work.

Another option is to host the website locally. In a terminal, do:

cd website/
python3 -m http.server 8000

Then, access the local website in your browser at localhost:8000. This option is nice because it allows Chrome extensions (like DarkReader) to work (Chrome extensions are not allowed to run on local file paths).

Updating the website hosted by GitHub pages

To update the class website hosted by GitHub pages, first install the ghp-import Python module:

pip install ghp-import

Then, simply run scripts/gh-pages-import.sh. This will overwrite the gh-pages branch of this repo with the current contents of the website/ directory.

Website history

After Dr. Archibald retired in August 2020, the BYU ECEn department discontinued ECEn 425. At some point in 2022, BYU also stopped hosting the original class website. Luckily, the class website was archived by Wayback Machine, and the website was saved to this repo on 2023-05-03 using this tool.