ARM Compiler toolchain Using the Linker - ARM Information Center

}
}
.ANY1(+RO) ; evenly distributed with er1
8.13.4 Controlling the placement of input sections for multiple .ANY selectors
Using scatter files
You can modify how the linker places unassigned input sections when using multiple .ANY
selectors by using a different placement algorithm or a different sort order. The following
command-line options are available:
• --any_placement=algorithm, where algorithm is one of first_fit, worst_fit, best_fit, or
next_fit
• --any_sort_order=order, where order is one of cmdline or descending_size.
Use first_fit when you want to fill regions in order.
Use best_fit when you want to fill regions to their maximum.
Use worst_fit when you want to fill regions evenly. With equal sized regions and sections
worst_fit fills regions cyclically.
Use next_fit when you need a more deterministic fill pattern.
If the linker attempts to fill a region to its limit, as it does with first_fit and best_fit, it might
overfill the region. This is because linker-generated content such as padding and veneers are not
known until sections have been assigned to .ANY selectors. If this occurs you might see the
following error:
Error: L6220E: Execution region regionname size (size bytes) exceeds limit (limit bytes).
The --any_contingency option prevents the linker from filling the region up to its maximum. It
reserves a portion of the region's size for linker-generated content and fills this contingency area
only if no other regions have space. It is enabled by default for the first_fit and best_fit
algorithms, because they are most likely to exhibit this behavior.
8.13.5 Specifying the maximum size permitted for placing unassigned sections
The execution region attribute ANY_SIZE max_size enables you to specify the maximum size in a
region that armlink can fill with unassigned sections.
Be aware of the following restrictions when using this keyword:
• max_size must be less than or equal to the region size
• you can use ANY_SIZE on a region without a .ANY selector but it is ignored by armlink.
When ANY_SIZE is present, armlink:
• Does not override a given .ANY size. That is, it does not reduce the priority then try to fit
more sections in later.
• Never recalculates contingency.
• Never assigns sections in the contingency space.
ANY_SIZE does not require --any_contingency to be specified. However, when --any_contingency
is specified and ANY_SIZE is not, armlink attempts to adjust contingencies. The aims are to:
• never overflow a .ANY region
• never refuse to place a section in a contingency reserved space.
If you specify --any_contingency on the command line, it is ignored for regions that have
ANY_SIZE specified. It is used as normal for regions that do not have ANY_SIZE specified.
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