Memory Utilization ===================== 'text' is what ends up in flash (only). 'data' is initialized variables: need to be storad in flash, then end up in RAM. 'bss' is uninitialized data: nothing in flash, but does consume RAM. The "-x --format=sysv" flags to arm-none-eabi-size can be helpful. Debugging ================ Access all registers: (gdb) x/x 0xE000ED14 0xe000ed14: Cannot access memory at address 0xe000ed14 (gdb) 0xe000ed18: Cannot access memory at address 0xe000ed18 (gdb) show mem inaccessible-by-default Unknown memory addresses will be treated as inaccessible. (gdb) set mem inaccessible-by-default off (gdb) x/x 0xE000ED14 0xe000ed14: 0x00000200 Uploading via SWD ==================== upload_blackmagic.sh: #!/bin/bash arm-none-eabi-gdb build/stm32f401cc_telemetry.elf < load_blackmagic.gdb sleep 1.0 load_blackmagic.gdb: target extended-remote /dev/ttyACM0 monitor swdp_scan attach 1 load quit References ============= Keil Application Note 209: Using Cortex-M3 and Cortex-M4 Fault Exceptions ARM Cortex-M3 HardFault Status Register Documentation: http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0553a/Cihdjcfc.html