9.5.3.1 Simple Assignments

A symbol may be assigned using any of the C-style assignment operators:

symbol = expression ;
symbol += expression ;
symbol -= expression ;
symbol *= expression ;
symbol /= expression ;
symbol <<= expression ;
symbol >>= expression ;
symbol &= expression ;
symbol |= expression ;

The first of the above examples will define symbol to have the value of expression. In the other examples, symbol must already be defined, and the value will be adjusted according to the results of the operation.

The special symbol name (.) indicates the location counter. This symbol may be only used within a SECTIONS command.

The semicolon after expression is required.

Expressions are defined in Expressions in Linker Scripts.

Symbol assignments may appear as commands in their own right, or as statements within a SECTIONS command, or as part of an output section description in a SECTIONS command.

The section of the symbol will be set from the section of the expression; for more information, see The Section of an Expression.

Here is an example showing the three different places that symbol assignments may be used:

floating_point = 0;
SECTIONS
{
  .text ORIGIN(kseg0_program_mem)  :
  {
    _text_begin = . ;
    *(.text .stub .text.* )
    _text_end = . ;
  } >kseg0_program_mem =0
    _bdata = (. + 3) & ~ 3;
    .data : { *(.data) }
}

In this example, the symbol floating_point will be defined as zero. The symbol _text_end will be defined as the address following the last .text input section. The symbol _bdata will be defined as the address following the .text output section aligned upward to a 4-byte boundary.