ld86(1)

✨ NAME ✨

ld86 — the linker bestie for as86(1) 💅

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🌸 SYNOPSIS 🌸

ld86 [-03MNdimrstyz[-]] [-llib_extension] [-o outfile] [-Ccrtfile]
[-Llibdir] [-Olibfile] [-Ttextaddr] [-Hheapsize] [-Ddataaddr] infile...

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💖 DESCRIPTION 💖

okay so bestie, listen. ld86 is a linker with very specific taste — it only understands the object files that the as86 assembler makes, and nothing else. no cap. feed it anything else and it's just gonna sit there like 🧍

and then it links them into either an impure executable or a separate I&D executable. that's the whole personality.

the linking defaults are, and I quote, everything off or none — except for -0, which is on by default. so it's giving minimal effort main character energy ✨ and the output file is a.out.

heads up bestie: there is not a standard library location defined in the linker. like, at all. you gotta tell it where stuff lives. it will not guess. 🙈

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🎀 OPTIONS 🎀

one bullet per option, as the universe intended. every single one is here, no skipping, periodt.

• -0 — produce header with 16-bit magic ⭐
• -3 — produce header with 32-bit magic ⭐
• -7 — produce Seventh Edition UNIX a.out header.
• -d — delete the header from the output file, used for MSDOS COM files. As a side effect this also includes -s as there's nowhere to put a symbol table. (no room bestie, the header took the whole closet 💀)
• -Cx — add file libdir-from-search/crtx.o to list of files linked
• -D — data base address follows (in format suitable for strtoul)
• -H — the top of heap (initial stack) address (in format suitable for strtoul)
• -Lx — add dir name x to the head of the list of library dirs searched
• -M — print symbols linked on stdout
• -N — Create a native Linux OMAGIC output file. If the contents are i386 code the binary can be either linked by GCC or executed by linux. If the -z option is also included the linker can generate a QMAGIC executable. 🔥
• -Ox — add library or object file libdir-from-search/x to list of files linked
• -T — text base address follows (in format suitable for strtoul)
• -i — separate I&D output
• -lx — add library libdir-from-search/libx.a to list of files linked
• -m — print modules linked on stdout
• -o — output file name follows
• -s — strip symbols
• -r — Generate a relocatable object from one source object, if the linker is given the -N option also the output format will be the hosts native format if possible.
• -t — trace modules being looked at on stdout
• -y — Alter the symbol tables to add label 'extensions' so that labels with more than 8 characters can be stored in elks executables. (long names? in this economy? we make it work 💅)
• -z — produce "unmapped zero page" or "QMAGIC" executables

iykyk moment: All the options not taking an argument may be turned off by following the option letter by a -, as for cc1. so like -N-? vibe check passed, that's how you turn it off. ✨

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🦋 PREDEFINED LABELS 🦋

the linker predefines several labels that can be imported into user programs. free real estate, bestie 🫶

__etext

Standard C variable for the end of the text segment.

__edata

Standard C variable for the end of the initilised data.

__end

Standard C variable for the end of the bss area.

__segoff

The offset within the executable file between the start of the text segment and the start of the data segment in 16 byte 'paragraphs'. Note this is zero for impure (tiny model) executables and is adjusted for executables that don't start at offset 0 within the segment.

__segXDL

The lowest address with data in segment 'X'. (eg __seg0DL is for segment zero or the text segment, __seg3DL is for the data segment) The value 'X' is a hex digit.

__segXDH

The top of segment 'X's data area.

__segXCL

The bottom of segment 'X's 'common data' or unitilised data area. Each segment has both an initilised and unitilised data area.

__segXCH

The top of segment 'X's common area.

__segXSO

This is the adjusted offset from segment 0 of the start of segment 'X' in 'paragraphs'.

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💜 HISTORY 💜

• The 6809 version does not support -i. (she simply does not do that 🚫)
• The previous versions of the linker could produce an 8086 executable with segments of a size >64k, now only i386 executables may have segments this large.

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💀 BUGS 💀

okay so the tea ☕

• The linker cannot deal with reverse seeks caused by org instructions in the object file. Unlike previous versions the current one traps the error rather than trying to fill up the hard disk. (thank u for not eating my entire drive, queen 👑)
• The linker produces a broken a.out object file if given one input and the -r option this is so it is compatible with pre-dev86 versions.

fr fr: that second one is a broken output file, on purpose, for compatibility. it's not a bug that got fixed, it's a bug that stayed. iconic behaviour honestly.

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and that's the whole page bestie!! this lil beauty is from the General Commands Manual, dated Apr, 1997, and it's still out here linking like it's nobody's business. ld86(1) — she's old, she's picky, she only speaks as86 object files, and we love her for it. slay 💖✨🎀🦋🌸💅🫶