You can include explicit bytes of data in an output section by using BYTE, SHORT, LONG, QUAD, or SQUAD as an output section command. Each keyword is followed by an expression in parentheses providing the value to store (see Expressions). The value of the expression is stored at the current value of the location counter.

The BYTE, SHORT, LONG, and QUAD commands store one, two, four, and eight bytes (respectively). After storing the bytes, the location counter is incremented by the number of bytes stored.

For example, this will store the byte 1 followed by the four byte value of the symbol addr:

BYTE(1)
LONG(addr)

When using a 64 bit host or target, QUAD and SQUAD are the same; they both store an 8 byte, or 64 bit, value. When both host and target are 32 bits, an expression is computed as 32 bits. In this case QUAD stores a 32 bit value zero extended to 64 bits, and SQUAD stores a 32 bit value sign extended to 64 bits.

If the object file format of the output file has an explicit endianness, which is the normal case, the value will be stored in that endianness. When the object file format does not have an explicit endianness, as is true of, for example, S-records, the value will be stored in the endianness of the first input object file.

You can include a zero-terminated string in an output section by using ASCIZ. The keyword is followed by a string which is stored at the current value of the location counter adding a zero byte at the end. If the string includes spaces it must be enclosed in double quotes. The string may contain \n, \r, \t and octal numbers. Hex numbers are not supported.

For example, this string of 16 characters will create a 17 byte area

  ASCIZ "This is 16 bytes"

Notethese commands only work inside a section description and not between them, so the following will produce an error from the linker:

SECTIONS { .text : { *(.text) } LONG(1) .data : { *(.data) } } 

whereas this will work:

SECTIONS { .text : { *(.text) ; LONG(1) } .data : { *(.data) } } 

FILL(0x90909090)

The FILL command is similar to the =fillexp output section attribute, but it only affects the part of the section following the FILL command, rather than the entire section. If both are used, the FILL command takes precedence. See Output Section Fill, for details on the fill expression.