8.4.5 Compression (--cinit_compression and --copy_compression Option)

By default, the linker does not compress copy table (Section 3.3.3 and Section 8.8) source data sections. The --cinit_compression and --copy_compression options specify compression through the linker.

The --cinit_compression option specifies the compression type the linker applies to the C autoinitialization copy table source data sections. The default is lzss.

Overlays can be managed by using linker-generated copy tables. To save ROM space the linker can compress the data copied by the copy tables. The compressed data is decompressed during copy. The --copy_compression option controls the compression of the copy data tables.

The syntax for the options are:

--cinit_compression[=compression_kind]

--copy_compression[=compression_kind]

The compression_kind can be one of the following types:

• off. Don't compress the data.
• rle. Compress data using Run Length Encoding.
• lzss. Compress data using Lempel-Ziv-Storer-Szymanski compression (the default if no compression_kind is specified).

Compressed sections within initialization tables are byte aligned in order to reduce the occurrence of holes in the .cinit table.

See Section 8.8.5 for more information about compression.