A root region is a region with the same load and execution address.
7.2.1 Root execution region and the initial entry point.
7.2.2 Root execution regions and the ABSOLUTE attribute.
7.2.3 Root execution regions and the FIXED attribute.
7.2.4 Methods of placing functions and data at specific addresses.
7.2.5 Placement of code and data with __attribute__((section("name"))).
7.2.6 Placement of __at sections at a specific address.
7.2.7 Restrictions on placing __at sections.
7.2.8 Automatic placement of __at sections.
7.2.9 Manual placement of __at sections.
7.2.10 Placement of a key in flash memory with an __at section.
7.2.11 Mapping a structure over a peripheral register with an __at section.