[Core] Add Reboot keycode to core (#15990)

platforms/avr/bootloaders/bootloadhid.c

@@ -31,3 +31,10 @@ __attribute__((weak)) void bootloader_jump(void) {
     for (;;)
         ;
 }
+
+__attribute__((weak)) void mcu_reset(void) {
+    // watchdog reset
+    wdt_enable(WDTO_250MS);
+    for (;;)
+        ;
+}

platforms/avr/bootloaders/caterina.c

@@ -37,3 +37,12 @@ __attribute__((weak)) void bootloader_jump(void) {
     while (1) {
     }
 }
+
+__attribute__((weak)) void mcu_reset(void) {
+    // setup watchdog timeout
+    wdt_enable(WDTO_60MS);
+
+    // wait for watchdog timer to trigger
+    while (1) {
+    }
+}

platforms/avr/bootloaders/custom.c

@@ -15,5 +15,14 @@
  */
 
 #include "bootloader.h"
+#include <avr/wdt.h>
 
 __attribute__((weak)) void bootloader_jump(void) {}
+__attribute__((weak)) void mcu_reset(void) {
+    // setup watchdog timeout
+    wdt_enable(WDTO_60MS);
+
+    // wait for watchdog timer to trigger
+    while (1) {
+    }
+}

platforms/avr/bootloaders/dfu.c

@@ -34,8 +34,15 @@ __attribute__((weak)) void bootloader_jump(void) {
     UCSR1B = 0;
     _delay_ms(5); // 5 seems to work fine
 
-    // watchdog reset
     reset_key = BOOTLOADER_RESET_KEY;
+    // watchdog reset
+    wdt_enable(WDTO_250MS);
+    for (;;)
+        ;
+}
+
+__attribute__((weak)) void mcu_reset(void) {
+    // watchdog reset
     wdt_enable(WDTO_250MS);
     for (;;)
         ;

platforms/avr/bootloaders/halfkay.c

@@ -17,6 +17,7 @@
 #include "bootloader.h"
 
 #include <avr/interrupt.h>
+#include <avr/wdt.h>
 #include <util/delay.h>
 
 __attribute__((weak)) void bootloader_jump(void) {
@@ -126,3 +127,12 @@ __attribute__((weak)) void bootloader_jump(void) {
     asm volatile("jmp 0x1FC00");
 #endif
 }
+
+__attribute__((weak)) void mcu_reset(void) {
+    // setup watchdog timeout
+    wdt_enable(WDTO_60MS);
+
+    // wait for watchdog timer to trigger
+    while (1) {
+    }
+}

platforms/avr/bootloaders/usbasploader.c

@@ -54,3 +54,12 @@ __attribute__((weak)) void bootloader_jump(void) {
 #endif
                    [bootaddrme] "M"((((FLASH_SIZE - BOOTLOADER_SIZE) >> 1) >> 8) & 0xff), [bootaddrlo] "M"((((FLASH_SIZE - BOOTLOADER_SIZE) >> 1) >> 0) & 0xff));
 }
+
+__attribute__((weak)) void mcu_reset(void) {
+    // setup watchdog timeout
+    wdt_enable(WDTO_15MS);
+
+    // wait for watchdog timer to trigger
+    while (1) {
+    }
+}