nrf_it.c

/*
 * Copyright (c) 2018 Particle Industries, Inc.  All rights reserved.
 *
 * 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/>.
 */

#include "nrf_it.h"
#include <stdbool.h>
#include <nrf52840.h>
#include <nrf_rtc.h>
#include <nrf_nvic.h>
#include "logging.h"
#include "hw_config.h"
#include "button_hal.h"
#include "hal_platform_nrf52840_config.h"
#include "security_mode.h"

extern void Timing_Decrement(void);

void HardFault_Handler( void ) __attribute__( ( naked ) );

__attribute__((externally_visible)) void prvGetRegistersFromStack( uint32_t *pulFaultStackAddress )
{
    /* These are volatile to try and prevent the compiler/linker optimising them
    away as the variables never actually get used.  If the debugger won't show the
    values of the variables, make them global my moving their declaration outside
    of this function. */
    volatile uint32_t r0;
    volatile uint32_t r1;
    volatile uint32_t r2;
    volatile uint32_t r3;
    volatile uint32_t r12;
    volatile uint32_t lr; /* Link register. */
    volatile uint32_t pc; /* Program counter. */
    volatile uint32_t psr;/* Program status register. */

    r0 = pulFaultStackAddress[ 0 ];
    r1 = pulFaultStackAddress[ 1 ];
    r2 = pulFaultStackAddress[ 2 ];
    r3 = pulFaultStackAddress[ 3 ];

    r12 = pulFaultStackAddress[ 4 ];
    lr = pulFaultStackAddress[ 5 ];
    pc = pulFaultStackAddress[ 6 ];
    psr = pulFaultStackAddress[ 7 ];

    /* Silence "variable set but not used" error */
    if (false) {
        (void)r0; (void)r1; (void)r2; (void)r3; (void)r12; (void)lr; (void)pc; (void)psr;
    }

    if (SCB->CFSR & (1<<25) /* DIVBYZERO */) {
        // stay consistent with the core and cause 5 flashes
        UsageFault_Handler();
    }
    else {
        PANIC(HardFault,"HardFault");

        /* Go to infinite loop when Hard Fault exception occurs */
        while (1)
        {
        }
    }
}


void HardFault_Handler(void)
{
    __asm volatile
    (
        " tst lr, #4                                                \n"
        " ite eq                                                    \n"
        " mrseq r0, msp                                             \n"
        " mrsne r0, psp                                             \n"
        " ldr r1, [r0, #24]                                         \n"
        " ldr r2, handler2_address_const                            \n"
        " bx r2                                                     \n"
        " .balign 4                                                 \n"
        " handler2_address_const: .word prvGetRegistersFromStack    \n"
    );
}

void MemManage_Handler(void)
{
    /* Go to infinite loop when Memory Manage exception occurs */
    PANIC(MemManage,"MemManage");
    while (1)
    {
    }
}

void BusFault_Handler(void)
{
    /* Go to infinite loop when Bus Fault exception occurs */
    PANIC(BusFault,"BusFault");
    while (1)
    {
    }
}

void UsageFault_Handler(void)
{
    /* Go to infinite loop when Usage Fault exception occurs */
    PANIC(UsageFault,"UsageFault");
    while (1)
    {
    }
}

void SysTick_Handler(void)
{
    System1MsTick();
    security_mode_notify_system_tick();
    Timing_Decrement();

#if HAL_PLATFORM_BUTTON_DEBOUNCE_IN_SYSTICK
    hal_button_timer_handler();
#endif
}