https://github.com/nzeemin/pclink11

Cross-linker, porting PDP-11 LINK to C/C++, WIP 🚧
https://github.com/nzeemin/pclink11

cplusplus cross-link linker pdp-11 pdp11 retrocomputing

Last synced: about 2 months ago
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Cross-linker, porting PDP-11 LINK to C/C++, WIP 🚧

• Host: GitHub
• URL: https://github.com/nzeemin/pclink11
• Owner: nzeemin
• License: lgpl-3.0
• Created: 2018-11-27T11:51:29.000Z (about 6 years ago)
• Default Branch: master
• Last Pushed: 2024-07-05T22:17:14.000Z (6 months ago)
• Last Synced: 2024-07-06T02:16:02.017Z (6 months ago)
• Topics: cplusplus, cross-link, linker, pdp-11, pdp11, retrocomputing
• Language: C++
• Homepage:
• Size: 1.89 MB
• Stars: 11
• Watchers: 5
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# pclink11

[![License: LGPL v3](https://img.shields.io/badge/License-LGPL%20v3-blue.svg)](https://www.gnu.org/licenses/lgpl-3.0)

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[![CodeFactor](https://www.codefactor.io/repository/github/nzeemin/pclink11/badge)](https://www.codefactor.io/repository/github/nzeemin/pclink11)

Attempt to port PDP-11 LINKer to PC C/C++ — learning how the linker works, the hard way.

The code (partially) ported from MACRO-11 sources to C/C++.

Port source: RT-11 LINK V05.45.

## Authors

 * Nikita Zimin (@nzeemin)

 * Vladimir Voroshilov (@voroshil)

## Status: Work in Progress 🚧

Currently the PCLINK11 links most of test OBJ files properly, but we have some troubles linking tests with libraries.

## Usage

The source code is able to compile under Windows (VS2013/VS2015), and also under Linux/MacOS (gcc/clang, use the Makefile).

Command line:

`pclink11 `

Options (both `/` and `-` prefixes are allowed):

- `-EXECUTE:filespec` — Specifies the name of the memory image file

- `-NOBITMAP` `-X` — Do not emit bit map

- `-WIDE` `-W` — Produces a load map that is 132-columns wide

- `-ALPHABETIZE` `-A` — Lists global symbols on the link map in alphabetical order

- `-SYMBOLTABLE` `-STB` — Generates a symbol table file (.STB file)

- `-MAP` — Generates map file

- `-FORLIB` `-F` — Include FORLIB.OBJ

- `-Q:section=address` — Set section to absolute address

- `--version` — Show the program version information

- `--help` — Show quick help on the command line options

Input files and options are space-separated.

Examples:

- `pclink11 HELLO.OBJ` — link the object file, will produce `HELLO.SAV` executable

- `pclink11 -MAP -SYMBOLTABLE -EXECUTE:LD.SYS LD.OBJ SYSLIB.OBJ -X` — link object file with system library, produce map file and symbol file, save output as `LD.SYS`, do not put bitmap in the first block

- `pclink11 TEST1.OBJ TEST2.OBJ -MAP -WIDE -A` — link two object files, generate map file with wide format, alphabetize list of symbols

## Testing Strategy

Folder `tests` contains more than 100 sub-folders with .OBJ files.

First, we use [RT-11 simulator](http://emulator.pdp-11.org.ru/RT-11/distr/) written by Dmitry Patronov to produce "etalon" or "original" output files, they renamed with `-11` suffix — see `!runtest11.cmd` command file.

Then, we run the `pclink11` with to produce "our" output files, they renamed with `-my` suffix — see `!runtestmy.cmd` command file and `testrunner` utility.

And finally, we compare "original" files with "our" files, line-to-line or byte-to-byte, using `testanalyzer` utility.

"Our" MAP files differs in the first line (program name, date/time, no page number), and there's no paging, so no page header lines.

SAV/SYS/REL and STB files are binary, compared byte-to-byte, should be no differences.

Log files are absolutely different, we're not comparing them, but in "our" log files we're looking for "SUCCESS"/"ERROR" and so on.

## TODO

First priority:

- Fix bugs for the failing test cases

Second priority:

- Need more tests, currently we have 120 test cases

- Reduce amount of logging, add option for verbosity level

- Process other command-line options, including file-specific ones

Not implemented now, and not sure we will:

- Link for foreground execution with `-R` or `-FOREGROUND` option, produce .REL file

- LDA output — produce a file in absolute binary loader format (option `-L`)

- Overlays

- Linkage with separated instructions/data spaces

## Links

- [DEC-11-ZLDA-D PDP-11 LINK-11 Linker and LIBR-11 Librarian May71](https://archive.org/details/bitsavers_decpdp11do11LINK11LinkerandLIBR11LibrarianMay71_1259623)

- [macro-11 - cross-assembler by Richard Krehbiel](https://github.com/simh/simtools/tree/master/crossassemblers/macro11)