A whirlwind tutorial on creating teensy ELF executables for Linux (1999)

A whirlwind tutorial on creating teensy ELF executables for Linux (1999)(muppetlabs.com)

59 points by xtacy 1 year ago | 17 comments

ptspts 1 year ago |

Shameless plug: write your program in C, get almost as little size overhead as in the Whirlwind turorial: https://github.com/pts/minilibc686 (libc, compiler, linker, settings)

dang 1 year ago |

Related. Others?

A Whirlwind Tutorial on Creating Teensy ELF Executables for Linux - https://news.ycombinator.com/item?id=32524007 - Aug 2022 (10 comments)

A Whirlwind Tutorial on Creating Really Teensy ELF Executables for Linux (1999) - https://news.ycombinator.com/item?id=21846785 - Dec 2019 (22 comments)

A Whirlwind Tutorial on Creating Really Teensy ELF Executables for Linux (2005) - https://news.ycombinator.com/item?id=11709247 - May 2016 (5 comments)

Creating Really Teensy ELF Executables for Linux - https://news.ycombinator.com/item?id=8745024 - Dec 2014 (13 comments)

The Teensy Files: Creating teensy ELF executables for Linux - https://news.ycombinator.com/item?id=8642734 - Nov 2014 (7 comments)

A Whirlwind Tutorial on Creating Really Teensy ELF Executables for Linux - https://news.ycombinator.com/item?id=5016434 - Jan 2013 (14 comments)

Tutorial on Creating Really Teensy ELF Executables for Linux - https://news.ycombinator.com/item?id=875077 - Oct 2009 (16 comments)

3998-byte executable reduced to 45 bytes - https://news.ycombinator.com/item?id=68056 - Oct 2007 (10 comments)

jart 1 year ago | |

Plus if you want them to run on four OSes: https://justine.lol/sizetricks/#elf

cryne 1 year ago |

I tried to replicate this on my 64 bit machine, so

  nasm -f elf64 tiny.s && ld -s tiny.o

  ; tiny.asm
  BITS 64
  GLOBAL _start
  SECTION .text
  _start:
                mov     eax, 1
                mov     ebx, 42  
                int     0x80

and this lands me at 4320 bytes! Why is there such a stark difference?

oguz-ismail 1 year ago | |

> Why is there such a stark difference?

Your linker must align the .text section to the page size (often 4096 bytes). If you open the binary with a hex editor you'll see lots of null padding.

yjftsjthsd-h 1 year ago | | |

If that's a hard lower limit, then it really invites a different sort of code golf / demo to see how much functionality you can stuff into a 4K(ish) binary

le-mark 1 year ago |

Does anyone recall an “intro to computing” style book that was available free online and starts with using the gas assembler and talked a lot about elf format executables? I lost the link a while ago and don’t recall the name.

tiu 1 year ago | |

You are probably thinking about Programming from the Ground Up by Jonathan Bartlett. There are many others in the same style though. He also has a newer book if I recall right.

https://www.amazon.com/Programming-Ground-Up-Jonathan-Bartle...

https://download-mirror.savannah.gnu.org/releases/pgubook/

deater 1 year ago |

for those excited about tiny ELF executables, or tiny programs in general, check out the Lovebyte size-coding demoparty happening next weekend. It's likely there will be a few tiny ELF entries there.

LegionMammal978 1 year ago | |

That's neat, I didn't know that there was much sizecoding activity with ELFs, except for the BGGP competitions [0]. (Mainly because it's not nearly as easy to output graphics than on all the old-school platforms, I'd imagine.) Does Lovebyte publish previous years' demos anywhere?

[0] https://binary.golf/

deater 1 year ago | | |

I don't know if there's a good way to search for them. Most of the Lovebyte entries can be found on pouet or demozoo.org but I don't know if there's an easy way to filter out only Linux entries.

I've written a few sizecoded raspberry pi entries, there's even a writeup of one of them in tmp.out where I loaded some code into the ELF headers https://tmpout.sh/3/08.html

lifthrasiir 1 year ago | | |

https://code.golf/ also has scoreboards for x86-64 Linux binaries.

hannob 1 year ago | |

Didn't know about that, will have to take a look.

I think I am the "inventor" of the first 64 and 32 byte intro competitions. (Just checked, we ran a 64 byte competition at the 0a000h 2002 and added 32 byte in 2003.) See https://0a000h.de/2002/ and https://0a000h.de/2003/ - releases are on scene.org