My point demonstrated from a snippet of isolinux.asm:
; -----------------------------------------------------------------------------
; Begin data section
; -----------------------------------------------------------------------------
section .data
boot_prompt db 'boot: ', 0
wipe_char db BS, ' ', BS, 0
err_notfound db 'Could not find kernel image: ',0
err_notkernel db CR, LF, 'Invalid or corrupt kernel image.', CR, LF, 0
err_noram db 'It appears your computer has less than '
asciidec dosram_k
db 'K of low ("DOS")'
db CR, LF
db 'RAM. Linux needs at least this amount to boot. If you get'
db CR, LF
db 'this message in error, hold down the Ctrl key while'
db CR, LF
db 'booting, and I will take your word for it.', CR, LF, 0
err_badcfg db 'Unknown keyword in config file.', CR, LF, 0
err_noparm db 'Missing parameter in config file.', CR, LF, 0
err_noinitrd db CR, LF, 'Could not find ramdisk image: ', 0
err_nohighmem db 'Not enough memory to load specified kernel.', CR,
LF, 0
err_highload db CR, LF, 'Kernel transfer failure.', CR, LF, 0
err_oldkernel db 'Cannot load a ramdisk with an old kernel image.'
db CR, LF, 0
err_notdos db ': attempted DOS system call', CR, LF, 0
err_comlarge db 'COMBOOT image too large.', CR, LF, 0
err_bssimage db 'BSS images not supported.', CR, LF, 0
err_a20 db CR, LF, 'A20 gate not responding!', CR, LF, 0
notfound_msg db 'not found', CR, LF, 0
localboot_msg db 'Booting from local disk...', CR, LF, 0
cmdline_msg db 'Command line: ', CR, LF, 0
ready_msg db 'Ready.', CR, LF, 0
trying_msg db 'Trying to load: ', 0
crlfloading_msg db CR, LF ; Fall through
loading_msg db 'Loading ', 0
dotdot_msg db '.'
dot_msg db '.', 0
fourbs_msg db BS, BS, BS, BS, 0
aborted_msg db ' aborted.', CR, LF, 0
crff_msg db CR, FF, 0
default_str db 'default', 0
default_len equ ($-default_str)
boot_dir db '/boot' ; /boot/isolinux
isolinux_dir db '/insert', 0 ; change this to allow multiple
isolinuxes on the same cd inside the /boot folder
ConfigName equ $
isolinux_cfg db 'isolinux.cfg', 0
err_disk_image db 'Cannot load disk image (invalid file)?', CR, LF, 0