11.3.3 Allocating Unmapped Sections

After all sections that appear in the section map are allocated, any remaining sections are considered to be unmapped. Unmapped sections are allocated according to section attributes. The linker uses a best-fit memory allocator to determine the most efficient arrangement in memory. The primary emphasis of the best-fit allocator is the reduction or elimination of memory gaps due to address alignment restrictions.

Since data memory is limited on many DSC devices, and several architectural features imply address alignment restrictions, efficient allocation of data memory is particularly important. By convention, data memory sections are not explicitly mapped in linker scripts, thus providing maximum flexibility for the best-fit memory allocator.

Section attributes affect memory allocation as described below. For a general discussion of section attributes, see Directives that Define Sections.