9.11.12 Tcm Variable Attribute

The tcm attribute can be applied to data items, where it directs the linker to place the item in the appropriate tightly-coupled memory (TCM) section, that being dtcm, or tcm on those processors where the code and data memory spaces are combined. If no such section is specified in the linker script, this attribute is ignored and a warning is printed. TCM can be used to provide faster and more predictable execution. See Chip-Level Security and Arm® TrustZone® Technology for more details on TCM. This attribute will generally not be supported by other distributions of gcc.