qmk_firmware/platforms/chibios/bootloaders/wb32_dfu.c

/* Copyright 2021 QMK
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "bootloader.h"

#include <ch.h>
#include <hal.h>
#include "wait.h"

extern uint32_t __ram0_end__;

/* This code should be checked whether it runs correctly on platforms */
#define SYMVAL(sym) (uint32_t)(((uint8_t *)&(sym)) - ((uint8_t *)0))
#define BOOTLOADER_MAGIC 0xDEADBEEF
#define MAGIC_ADDR (unsigned long *)(SYMVAL(__ram0_end__) - 4)

__attribute__((weak)) void bootloader_jump(void) {
    *MAGIC_ADDR = BOOTLOADER_MAGIC; // set magic flag => reset handler will jump into boot loader
    NVIC_SystemReset();
}

void enter_bootloader_mode_if_requested(void) {
    unsigned long *check = MAGIC_ADDR;
    if (*check == BOOTLOADER_MAGIC) {
        *check = 0;
        __set_CONTROL(0);
        __set_MSP(*(__IO uint32_t *)WB32_BOOTLOADER_ADDRESS);
        __enable_irq();

        typedef void (*BootJump_t)(void);
        BootJump_t boot_jump = *(BootJump_t *)(WB32_BOOTLOADER_ADDRESS + 4);
        boot_jump();
        while (1)
            ;
    }
}