flasher.c

#include "bl.h"

#include <libopencm3/stm32/flash.h>
#include <libopencm3/cm3/nvic.h>
#include <libopencm3/cm3/cortex.h>
#include <string.h>

#define BINDATA_SIZE (32 * 1024)

extern const uint8_t bindata[];

extern uint32_t vector_table[];

void flushFlash(void) {}

void delay(unsigned msec) {
    int k = msec * 15000;
    while (k--)
        asm("nop");
}

void flash_bootloader(void) {
    cm_disable_interrupts();

    flash_unlock();

    uint32_t dst = 0x08000000;

    if (memcmp((void*)dst, bindata, BINDATA_SIZE) == 0) {
        screen_init();
        print(3, 3, 6, "You already have\nthis bootloader");
        print(3, 100, 5, "Press reset");
        draw_screen();
        for (;;)
            ;
    }

    uint32_t optcr = FLASH_OPTCR;
    optcr &= ~0x80000000;
    optcr |= 0x00030000;

    if (FLASH_OPTCR != optcr) {
        flash_program_option_bytes(optcr);
        resetIntoApp();
    }

    // erase bootloader
    flash_erase_sector(0, FLASH_CR_PROGRAM_X32);
    flash_erase_sector(1, FLASH_CR_PROGRAM_X32);

    for (int i = 0; i < BINDATA_SIZE; i += 4) {
        flash_program_word(dst + i, *(uint32_t *)(bindata + i));
    }

    if (memcmp((void*)dst, bindata, BINDATA_SIZE) != 0) {
        screen_init();
        print(3, 3, 6, "Failed to erase!");
        draw_screen();
        for (;;)
            ;
    }

    // self-destruct
    flash_program_word((uint32_t)vector_table, 0);
    flash_program_word((uint32_t)vector_table + 4, 0);

    // write-protect
    optcr &= ~0x00030000;
    flash_program_option_bytes(optcr);

    screen_init();
    print(3, 3, 6, "Bootloader updated!");
    print4(3, 40, 4, "Yay:)");
    print(3, 100, 5, "Press reset");
    draw_screen();

    for (;;) {
        led_off(LED_BOOTLOADER);
        delay(300);
        led_on(LED_BOOTLOADER);
        delay(100);
    }

    // resetIntoBootloader();
}