9.5.5.9.4 Output Section Fill

A fill pattern can be set for an entire section by using =fillexp. The fillexp is an expression. Any otherwise unspecified regions of memory within the output section (for example, gaps left due to the required alignment of input sections) will be filled with the two least significant bytes of the value, repeated as necessary.

The fill value can also be changed with a FILL command in the output section commands; see Output Section Data.

Here is a simple example:

SECTIONS { .text : { *	(.text) } =0x9090 }