__attribute__((section("name"))) variable attribute

Normally, the ARM compiler places the objects it generates in sections like .data and .bss. However, you might require additional data sections or you might want a variable to appear in a special section, for example, to map to special hardware. The section attribute specifies that a variable must be placed in a particular data section. If you use the section attribute, read-only variables are placed in RO data sections, read-write variables are placed in RW data sections unless you use the zero_init attribute. In this case, the variable is placed in a ZI section.

/* in RO section */
const int descriptor[3] __attribute__((section ("descr"))) = { 1,2,3 };

/* in RW section */
long long rw_initialized[10] __attribute__((section ("INITIALIZED_RW"))) = {5};

/* in RW section */
long long rw[10] __attribute__((section ("RW")));

/* in ZI section */
long long altstack[10] __attribute__((section ("STACK"), zero_init));