Refactor bootloader_jump() implementations (#15450)

* Refactor `bootloader_jump()` implementations

* Fix tests?

* Rename `atmel-samba` to `md-boot`

platforms/chibios/bootloaders/kiibohd.c

@@ -0,0 +1,33 @@
+/* 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 <ch.h>
+
+/* 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\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00";
+
+__attribute__((weak))
+void bootloader_jump(void) {
+    void *volatile vbat = (void *)VBAT;
+    __builtin_memcpy(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;
+}