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:
<http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0553a/Cihdjcfc.html>

"STM32/ARM Cortex-M3 HOWTO: Development under Ubuntu (Debian)" (from fun-tech.se:
<http://fun-tech.se/stm32/)>