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_project.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

“STM32/ARM Cortex-M3 HOWTO: Development under Ubuntu (Debian)” (fun-tech.se)