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RIOT/cpu/avr8_common/startup.c

102 lines
2.6 KiB
C

/*
* Copyright (C) 2014 Freie Universität Berlin, Hinnerk van Bruinehsen
* 2021 Gerson Fernando Budke
* 2023 Hugues Larrive
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @ingroup cpu_avr8_common
* @{
*
* @file
* @brief Startup code and interrupt vector definition
*
* @author Hinnerk van Bruinehsen <h.v.bruinehsen@fu-berlin.de>
* @author Josua Arndt <jarndt@ias.rwth-aachen.de>
* @author Steffen Robertz <steffen.robertz@rwth-aachen.de>
* @author Gerson Fernando Budke <nandojve@gmail.com>
* @author Hugues Larrive <hugues.larrive@pm.me>
* @}
*/
#include <stdint.h>
#include <avr/interrupt.h>
#include <avr/io.h>
/* For Catchall-Loop */
#include "board.h"
#ifdef MODULE_PUF_SRAM
#include "puf_sram.h"
#endif
#ifdef MODULE_DBGPIN
#include "dbgpin.h"
#endif
/**
* @brief functions for initializing the board, std-lib and kernel
*/
extern void board_init(void);
extern void cpu_init(void);
extern void kernel_init(void);
extern void __libc_init_array(void);
/**
* @brief This pair of functions hook circumvent the call to main
*
* avr-libc normally uses the .init9 section for a call to main. This call
* seems to be not replaceable without hacking inside the library. We
* circumvent the call to main by using section .init7 to call the function
* reset_handler which therefore is the real entry point and section .init8
* which should never be reached but just in case jumps to exit.
* This way there should be no way to call main directly.
*/
void init7_ovr(void) __attribute__((section(".init7")));
void init8_ovr(void) __attribute__((section(".init8")));
__attribute__((used, naked)) void init7_ovr(void)
{
#if (FLASHEND <= 0x1FFF)
__asm__ ("rjmp reset_handler");
#else
__asm__ ("call reset_handler");
#endif
}
__attribute__((used, naked)) void init8_ovr(void)
{
#if (FLASHEND <= 0x1FFF)
__asm__ ("rjmp exit");
#else
__asm__ ("jmp exit");
#endif
}
/**
* @brief This function is the entry point after a system reset
*
* After a system reset, the following steps are necessary and carried out:
* 1. initialize the board (sync clock, setup std-IO)
* 2. initialize and start RIOTs kernel
*/
__attribute__((used)) void reset_handler(void)
{
#ifdef MODULE_PUF_SRAM
puf_sram_init((uint8_t *)RAMEND-SEED_RAM_LEN, SEED_RAM_LEN);
#endif
#ifdef MODULE_DBGPIN
dbgpin_init();
#endif
/* initialize the CPU */
cpu_init();
/* initialize the board and startup the kernel */
board_init();
/* startup the kernel */
kernel_init();
}