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Diffstat (limited to 'platforms/avr/bootloaders/usbasploader.c')
-rw-r--r--platforms/avr/bootloaders/usbasploader.c56
1 files changed, 56 insertions, 0 deletions
diff --git a/platforms/avr/bootloaders/usbasploader.c b/platforms/avr/bootloaders/usbasploader.c
new file mode 100644
index 0000000000..008bd16069
--- /dev/null
+++ b/platforms/avr/bootloaders/usbasploader.c
@@ -0,0 +1,56 @@
+/* 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>
+
+#define FLASH_SIZE (FLASHEND + 1L)
+
+#if !defined(MCUCSR)
+# if defined(MCUSR)
+# define MCUCSR MCUSR
+# endif
+#endif
+
+__attribute__((weak)) void bootloader_jump(void) {
+ // Taken with permission of Stephan Baerwolf from https://github.com/tinyusbboard/API/blob/master/apipage.c
+
+ wdt_enable(WDTO_15MS);
+ wdt_reset();
+ asm volatile("cli \n\t"
+ "ldi r29 , %[ramendhi] \n\t"
+ "ldi r28 , %[ramendlo] \n\t"
+#if (FLASHEND > 131071)
+ "ldi r18 , %[bootaddrhi] \n\t"
+ "st Y+, r18 \n\t"
+#endif
+ "ldi r18 , %[bootaddrme] \n\t"
+ "st Y+, r18 \n\t"
+ "ldi r18 , %[bootaddrlo] \n\t"
+ "st Y+, r18 \n\t"
+ "out %[mcucsrio], __zero_reg__ \n\t"
+ "bootloader_startup_loop%=: \n\t"
+ "rjmp bootloader_startup_loop%= \n\t"
+ :
+ : [mcucsrio] "I"(_SFR_IO_ADDR(MCUCSR)),
+#if (FLASHEND > 131071)
+ [ramendhi] "M"(((RAMEND - 2) >> 8) & 0xff), [ramendlo] "M"(((RAMEND - 2) >> 0) & 0xff), [bootaddrhi] "M"((((FLASH_SIZE - BOOTLOADER_SIZE) >> 1) >> 16) & 0xff),
+#else
+ [ramendhi] "M"(((RAMEND - 1) >> 8) & 0xff), [ramendlo] "M"(((RAMEND - 1) >> 0) & 0xff),
+#endif
+ [bootaddrme] "M"((((FLASH_SIZE - BOOTLOADER_SIZE) >> 1) >> 8) & 0xff), [bootaddrlo] "M"((((FLASH_SIZE - BOOTLOADER_SIZE) >> 1) >> 0) & 0xff));
+}