PPK debuts the tiny programming challenge

kernelistic writes "Looks like the great folks at properkernel.com are running a developer challenge. They're looking for smallest executables that match the posted criteria. The rules look fairly straightforward. Anyone up for some fun?"

Comments

howto of sorts...

[raulmazda]

Looks like they want a binary similar to the one described in A Whirlwind Tutorial on Creating Really Teensy ELF Executables for Linux , except it has to print text and not just return 42.

If only I had some spare time to play along at home...

Interesting challenge.

[AJWM]

Just for comparison's sake, the quick'n'dirty approach:

main()
{
char *msg = "The deep gray mouse runs after the holy yellow cheese.\n";
write(1, msg, 56);
}

produces, stripped, a 3200 byte binary -- too big to qualify by 700 bytes.

super easy to beat the limit...

[Just6979]

justin@joker:~/tmp[1]$ cat small.s
; Justin White
; http://properkernel.com/tiny/ entry

%define STDOUT 0
%define SYS_exit 1
%define SYS_write 4

section data
msg db "The deep gray mouse runs after the holy yellow cheese.", 0x0A
msg_size equ $-msg

section text
global _start
_start:
; write
push dword msg_size
push dword msg
push dword STDOUT
mov eax, SYS_write
push eax
int 0x80
; exit
push dword 0
mov eax, SYS_exit
push eax
int 0x80
; end _start

;EOF
justin@joker:~/tmp[0]$ nasm -f elf small.s
justin@joker:~/tmp[0]$ ld -x -s -o small -nostdlib --stats small.o
/usr/libexec/elf/ld: total time in link: 0.006606
/usr/libexec/elf/ld: data size 184328
justin@joker:~/tmp[0]$ ll small
-rwxrwxr-x 1 justin justin 516 Nov 25 03:22 small*
justin@joker:~/tmp[0]$ ./small
The deep gray mouse runs after the holy yellow cheese.
justin@joker:~/tmp[0]$

that's using FreeBSD kernel calls.

that's the smallest it'll be without doing ELF header tweaking like in that tiny binary tutorial.

actually, can save like 8 bytes by using just AL and not all of EAX to hold the syscall numbers.

now, if they said, do it without using the kernel, that would have been a challenge :P