qmk_firmware/tmk_core/common/chibios/bootloader.c

#include "bootloader.h"

#include "ch.h"
#include "hal.h"

#ifdef STM32_BOOTLOADER_ADDRESS
/* STM32 */

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

/** \brief Jump to the bootloader
 *
 * FIXME: needs doc
 */
void bootloader_jump(void) {
    *MAGIC_ADDR = BOOTLOADER_MAGIC;  // set magic flag => reset handler will jump into boot loader
    NVIC_SystemReset();
}

/** \brief Enter bootloader mode if requested
 *
 * FIXME: needs doc
 */
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 *)STM32_BOOTLOADER_ADDRESS);
        __enable_irq();

        typedef void (*BootJump_t)(void);
        BootJump_t boot_jump = *(BootJump_t *)(STM32_BOOTLOADER_ADDRESS + 4);
        boot_jump();
        while (1)
            ;
    }
}

#elif defined(KL2x) || defined(K20x) /* STM32_BOOTLOADER_ADDRESS */
/* Kinetis */

#    if defined(BOOTLOADER_KIIBOHD)
/* Kiibohd Bootloader (MCHCK and Infinity KB) */
#        define SCB_AIRCR_VECTKEY_WRITEMAGIC 0x05FA0000
const uint8_t sys_reset_to_loader_magic[] = "\xff\x00\x7fRESET TO LOADER\x7f\x00\xff";
void          bootloader_jump(void) {
    __builtin_memcpy((void *)VBAT, (const void *)sys_reset_to_loader_magic, sizeof(sys_reset_to_loader_magic));
    // request reset
    SCB->AIRCR = SCB_AIRCR_VECTKEY_WRITEMAGIC | SCB_AIRCR_SYSRESETREQ_Msk;
}

#    else /* defined(BOOTLOADER_KIIBOHD) */
/* Default for Kinetis - expecting an ARM Teensy */
#        include "wait.h"
void bootloader_jump(void) {
    wait_ms(100);
    __BKPT(0);
}
#    endif /* defined(BOOTLOADER_KIIBOHD) */

#else /* neither STM32 nor KINETIS */
__attribute__((weak)) void bootloader_jump(void) {}
#endif