There are a few other linker scripts commands.
EXTERN, and you may use
EXTERNmultiple times. This command has the same effect as the -u command-line option.
ldomit the assignment of addresses to common symbols even for a non-relocatable output file.
In certain types of programs, particularly on embedded systems when using overlays, when one section is loaded into memory, another section will not be. Any direct references between the two sections would be errors. For example, it would be an error if code in one section called a function defined in the other section.
NOCROSSREFS command takes a list of output section names. If
ld detects any cross references between the sections, it reports
an error and returns a non-zero exit status. Note that the
NOCROSSREFS command uses output section names, not input section
objdumpprogram with the -f option.