11–18 of 18 posts
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?
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.
Earlier quoted context omitted.
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/
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
https://www.pouet.net/prodlist.php?type[]=32b&type[]=64b&typ...
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.
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/
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.
https://www.amazon.com/Programming-Ground-Up-Jonathan-Bartle...
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?
> 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.
Earlier quoted context omitted.
> 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.
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
I think it's some sort of optimization (retrieving one page of memory should be easier than two, right?). With GNU ld I can do
ld -s -Ttext=0x4000b0 tiny.o
Earlier quoted context omitted.
> 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.
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
[0] https://tmpout.sh/3/22.html
[1] https://github.com/binarygolf/BGGP/pull/3/files, assembly at https://gist.github.com/LegionMammal978/347c939def56dcba449c...
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.
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