4.1 Examples

Here are some examples of writing declarations and definitions for various kinds of data types.

The following demonstrates the use of the .word, .half, .byte, .xword, nword, and .asciiz pseudo-ops, along with .align, .skip, .global, and .local, to define data in .data, .rodata, and .bss sections.

! --------.data-----------------
        ! the .data section is used for normal read/write data
        .section        ".data"

        ! iii is a global integer (word), "iii"
        .global iii
        .align  4
iii:
        .word   12345678


        ! sss is a global short (half)
        .global sss
        .align  2
sss:
        .half   12345


        ! ccc is a static (local) char (byte)
        .local  ccc
        .align  1
ccc:
        .byte   12


        ! lll is a a global long long (xword)
        .global lll
        .align  8
lll:
        .xword  1234567812345678


        ! aaa is a global char string 
        .global aaa
        .align  1
aaa:
        .asciiz "a string"


        ! sss is a global pointer to a string (absolute addressing)
        .global sss
        .align  8
sss:
        .nword  aaa


        ! --------.rodata-------------------
        ! the .rodata section is used for read-only data
        .section        ".rodata"

        ! jjj is a global read-only integer (word)
        .global jjj
        .align  4
jjj:
        .word   12345678


        ! ---------.bss---------------------
        ! the .bss section is used for data allocated (as zeroes) at run-time
        ! data in this section does not occupy space in the ELF file
        .section        ".bss"

        ! kkk is a global "bss" integer allocated at run-time 
        .global kkk
        .align  4
kkk:
        .skip   4