; quine.iso / quine.asm ; ; This file is a polyglot double-quine! ; ; It's a polyglot because it's simultaneously a valid ISO disc image, ; and NASM assembler source code. When read as an ISO, on it are two ; identical copies of itself named "quine.iso" and "quine.asm". When ; assembled with NASM, the output is also itself. A double-quine! ; ; By Sijmen J. Mulder , 2026 %define be16(n) (n&0xFF)<<8 | (n&0xFF00)>>8 %define be32(n) (n&0xFF)<<24 | (n&0xFF00)<<8 | \ (n&0xFF0000)>>8 | (n&0xFF000000)>>24 %define lb16(n) n, be16(n) %define lb32(n) n, be32(n) %define cdiv(x,n) (x+n-1)/n %define lba(n) n/BLOCK_SZ BLOCK_SZ: equ 0x800 SECTOR_SZ: equ 0x800 ASM_SZ: equ 0x1000 VD_PRIMARY: equ 0x01 VD_TERMINATOR: equ 0xFF ID_SELF: equ 0x00 ID_PARENT: equ 0x01 FF_DIRECTORY: equ 1<<1 ; Generates a directory entry ; ; Arguments: ; - varable name of the extent (also define %_sz) ; - identifier ; - flags %macro dir_ent 3 %%ent: db %%sz ; entry size db 0 ; atribute record length dd lb32(lba(%1)) ; location dd lb32(%1_sz) ; size times 7 db 0 ; date db %3 ; flags db 0 ; interleaved unit size db 0 ; interleaved gap size dw lb16(1) ; volume db %%idzs ; ID length %%id: db %2 ; ID %%idzs: equ $-%%id alignb 2 %%sz: equ $-%%ent %endmacro file: equ 0 incbin __?FILE?__, 0, ASM_SZ %if $-$$ < ASM_SZ db `\n%if 0\n` times ASM_SZ-($-$$) db 0 %endif alignb BLOCK_SZ le_paths: equ $-$$ db 1 ; ID length db 0 ; extended attribute length dd lba(root_ext) ; location dw 1 ; parent number (self) db ID_SELF ; ID alignb 2 le_paths_sz: equ $-$$-le_paths alignb BLOCK_SZ be_paths: equ $-$$ db 1 ; ID length db 0 ; extended attribute length dd be32(lba(root_ext)) ; location dw be16(1) ; parent number (self) db ID_SELF ; ID alignb 2 be_paths_sz: equ $-$$-be_paths alignb BLOCK_SZ root_ext: equ $-$$ dir_ent root_ext, ID_SELF, FF_DIRECTORY dir_ent root_ext, ID_PARENT, FF_DIRECTORY dir_ent file, "QUINE.ISO;1", 0 dir_ent file, "QUINE.ASM;1", 0 root_ext_sz: equ $-$$-root_ext times 0x8000-($-$$) db 0 db VD_PRIMARY db 'CD001' db 0x01 ; version db 0x00 ; unused times 32 db ' ' ; boot system identifier .id: db 'QUINE' ; volume identifier times 32-($-.id) db ' ' times 8 db 0 ; unused dd lb32(cdiv(file_sz, BLOCK_SZ)) ; volume space size times 32 db 0 ; unused dw lb16(1) ; volume set size dw lb16(1) ; volume sequence number dw lb16(BLOCK_SZ) ; block size dd lb32(le_paths_sz) ; path table size dd lba(le_paths) ; path table (LE) dd 0 ; optional path table (LE) dd be32(lba(be_paths)) ; path table (BE) dd be32(0) ; optional path table (BE) dir_ent root_ext, ID_SELF, FF_DIRECTORY .vsid: db 'QUINE' ; volume set ID times 128-($-.vsid) db ' ' .pid: db 'SJ_MULDER' ; publisher times 128-($-.pid) db ' ' times 128 db ' ' ; data preparer ID times 128 db ' ' ; app ID times 37 db ' ' ; copyright file times 37 db ' ' ; abstract file times 37 db ' ' ; bibliographic file db '0000000000000000',0 ; creation date db '0000000000000000',0 ; modification date db '0000000000000000',0 ; expiration date db '0000000000000000',0 ; effective date db 0x01 ; structure version db 0 ; unused times 512 db 0 ; application used alignb SECTOR_SZ db VD_TERMINATOR db 'CD001' db 0x01 ; version times 0x9000-8-($-$$) db 0 db `\n%endif\n` file_sz: equ $-$$ %if 0 "œœ"œœ, QUINE.ISO;1, QUINE.ASM;1CD001 QUINE  "œœQUINE SJ_MULDER 0000000000000000000000000000000000000000000000000000000000000000ÿCD001 %endif