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Diffstat (limited to 'platforms/avr/bootloaders/dfu.c')
-rw-r--r-- | platforms/avr/bootloaders/dfu.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/platforms/avr/bootloaders/dfu.c b/platforms/avr/bootloaders/dfu.c new file mode 100644 index 0000000000..bdf5908934 --- /dev/null +++ b/platforms/avr/bootloaders/dfu.c @@ -0,0 +1,53 @@ +/* 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 <avr/wdt.h> +#include <util/delay.h> + +#define FLASH_SIZE (FLASHEND + 1L) + +/** \brief Entering the Bootloader via Software + * + * http://www.fourwalledcubicle.com/files/LUFA/Doc/120730/html/_page__software_bootloader_start.html + */ +#define BOOTLOADER_RESET_KEY 0xB007B007 +uint32_t reset_key __attribute__((section(".noinit,\"aw\",@nobits;"))); + +__attribute__((weak)) +void bootloader_jump(void) { + UDCON = 1; + USBCON = (1 << FRZCLK); // disable USB + UCSR1B = 0; + _delay_ms(5); // 5 seems to work fine + + // watchdog reset + reset_key = BOOTLOADER_RESET_KEY; + wdt_enable(WDTO_250MS); + for (;;) + ; +} + +/* this runs before main() */ +void bootloader_jump_after_watchdog_reset(void) __attribute__((used, naked, section(".init3"))); +void bootloader_jump_after_watchdog_reset(void) { + if ((MCUSR & (1 << WDRF)) && reset_key == BOOTLOADER_RESET_KEY) { + reset_key = 0; + + ((void (*)(void))((FLASH_SIZE - BOOTLOADER_SIZE) >> 1))(); + } +} |