3.5.9 How Do I Utilize/Allocate the RAM Banks on My Device?

The compiler will automatically use all the available RAM banks on the device you are programming. It is only if you wish to alter the default memory allocation that you need take any action. Special bank() qualifiers (see 5.3.9.1 Bank Type Qualifier) and an option (see 4.6.1.1 Addrqual Option) to indicate how these qualifiers are interpreted are used to manually allocate variables.

Note that there is no guarantee that all the memory on a device can be utilized as data and code is packed in sections, or psects.