Почему контроллер (stm32l476rg) падает в hard fault?

Question

Дмитрий @looogle

Программист-любитель на C++ и по жизни.

C
STM

Почему контроллер (stm32l476rg) падает в hard fault?

Пытаюсь запустить программу моргания светодиодами на STM32L476RG. Программа успешно прошивается и запускается. Выполняется начальная инициализация, но когда программа делает переход на main() -- получаю hard fault:

signal handler called () at 0xfffffff9

Для прошивки использую openocd. Использую библиотеку libopencm3, поэтому скрипт линкера выглядит так:

MEMORY
{
   rom (rx) : ORIGIN = 0x08000000, LENGTH = 1024K
   ram (rwx) : ORIGIN = 0x20000000, LENGTH = 128K
}

INCLUDE libopencm3_stm32l4.ld

Полный скрипт libopencm3_stm32l4.ld ниже.

/*
 * This file is part of the libopencm3 project.
 *
 * Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
 *
 * This library is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library.  If not, see <http://www.gnu.org/licenses/>.
 */

/* Generic linker script for STM32 targets using libopencm3. */

/* Memory regions must be defined in the ld script which includes this one. */

/* Enforce emmition of the vector table. */
EXTERN (vector_table)

/* Define the entry point of the output file. */
ENTRY(reset_handler)

/* Define sections. */
SECTIONS
{
    .text : {
        *(.vectors) /* Vector table */
        *(.text*)   /* Program code */
        . = ALIGN(4);
        *(.rodata*) /* Read-only data */
        . = ALIGN(4);
    } >rom

    /* C++ Static constructors/destructors, also used for __attribute__
     * ((constructor)) and the likes */
    .preinit_array : {
        . = ALIGN(4);
        __preinit_array_start = .;
        KEEP (*(.preinit_array))
        __preinit_array_end = .;
    } >rom
    .init_array : {
        . = ALIGN(4);
        __init_array_start = .;
        KEEP (*(SORT(.init_array.*)))
        KEEP (*(.init_array))
        __init_array_end = .;
    } >rom
    .fini_array : {
        . = ALIGN(4);
        __fini_array_start = .;
        KEEP (*(.fini_array))
        KEEP (*(SORT(.fini_array.*)))
        __fini_array_end = .;
    } >rom

    /*
     * Another section used by C++ stuff, appears when using newlib with
     * 64bit (long long) printf support
     */
    .ARM.extab : {
        *(.ARM.extab*)
    } >rom
    .ARM.exidx : {
        __exidx_start = .;
        *(.ARM.exidx*)
        __exidx_end = .;
    } >rom

    . = ALIGN(4);
    _etext = .;

    .data : {
        _data = .;
        *(.data*)   /* Read-write initialized data */
        . = ALIGN(4);
        _edata = .;
    } >ram AT >rom
    _data_loadaddr = LOADADDR(.data);

    .bss : {
        *(.bss*)    /* Read-write zero initialized data */
        *(COMMON)
        . = ALIGN(4);
        _ebss = .;
    } >ram

    /*
     * The .eh_frame section appears to be used for C++ exception handling.
     * You may need to fix this if you're using C++.
     */
    /DISCARD/ : { *(.eh_frame) }

    . = ALIGN(4);
    end = .;
}

PROVIDE(_stack = ORIGIN(ram) + LENGTH(ram));

Параметры компилятора:

arm-none-eabi-g++ -mcpu=cortex-m4 -march=armv7e-m -mthumb -mfloat-abi=hard -mfpu=fpv4-sp-d16 -munaligned-access -O0 -fmessage-length=0 -fsigned-char -ffunction-sections -fdata-sections -g3 ...

Собственно как можно локализировать источник проблемы? Где собака зарыта?

Upd:
Вид дебаггера при остановке при hard fault.