Uninitialized variables is getting assigned to DATA section instead of BSS section in ARM Compiler 6.6

• the section attribute as you already use (you can use macros to add the prefix".bss." rather than writing it down all the time)
• #pragma arm section is another way to control the sections, I've never used it but you can read the documentation at https://developer.arm.com/docs/dui0774/h/compiler-specific-pragmas/pragma-clang-section

The latter seems to be what you want:

// set bss section to .myRegion
#pragma clang section bss=".myRegion"
unsigned char myData[0x2000];
// reset bss section to original
#pragma clang section bss=""

• the section attribute as you already use (you can use macros to add the prefix".bss." rather than writing it down all the time)
• #pragma arm section is another way to control the sections, I've never used it but you can read the documentation at https://developer.arm.com/docs/dui0774/h/compiler-specific-pragmas/pragma-clang-section

The latter seems to be what you want:

// set bss section to .myRegion
#pragma clang section bss=".myRegion"
unsigned char myData[0x2000];
// reset bss section to original
#pragma clang section bss=""