Section alignment with the linker
The linker ensures each input section starts at an address that is a multiple of the input section alignment.
When input sections have been ordered and before the base addresses are fixed, armlink inserts padding, if required, to force each input section to start at an address that is a multiple of the input section alignment.
The linker permits ELF program headers and output sections to be aligned on a four-byte boundary regardless of the maximum alignment of the input sections. This enables armlink to minimize the amount of padding that it inserts into the image.
If you require strict conformance with the ELF specification then use the
--no_legacyalign option. The linker faults the base address of a region
if it is not aligned so padding might be inserted to ensure compliance. When
--no_legacyalign is used the region alignment is the maximum alignment of
any input section contained by the region.
If you are using scatter-loading, you can increase the alignment of a load region or
execution region with the
ALIGN attribute. For example, you can change an
execution region that is normally four-byte aligned to be eight-byte aligned. However, you
cannot reduce the natural alignment. For example, you cannot force two-byte alignment on a
region that is normally four-byte aligned.