Fix for possible break of DFU functionality

STM32F1/cores/maple/usb_serial.cpp

@@ -273,18 +273,6 @@ static void ifaceSetupHook(unsigned hook __attribute__((unused)), void *requestv
 #endif	
 }
 
-#define RESET_DELAY 100000
-#ifdef SERIAL_USB 
-static void wait_reset(void) {
-  delay_us(RESET_DELAY);
-  nvic_sys_reset();
-}
-#endif
-
-
-#define STACK_TOP 0x20000800
-#define EXC_RETURN 0xFFFFFFF9
-#define DEFAULT_CPSR 0x61000000
 static void rxHook(unsigned hook __attribute__((unused)), void *ignored __attribute__((unused))) {
 static const uint8 magic[4] = {'1', 'E', 'A', 'F'};	
     /* FIXME this is mad buggy; we need a new reset sequence. E.g. NAK
@@ -309,34 +297,11 @@ static const uint8 magic[4] = {'1', 'E', 'A', 'F'};
 #ifdef SERIAL_USB 
             // The magic reset sequence is "1EAF".
             // Got the magic sequence -> reset, presumably into the bootloader.
-            // Return address is wait_reset, but we must set the thumb bit.
 			bkp_init();
 			bkp_enable_writes();
 			bkp_write(10, 0x424C);
 			bkp_disable_writes();
-
-            uintptr_t target = (uintptr_t)wait_reset | 0x1;
-            asm volatile("mov r0, %[stack_top]      \n\t" // Reset stack
-                         "mov sp, r0                \n\t"
-                         "mov r0, #1                \n\t"
-                         "mov r1, %[target_addr]    \n\t"
-                         "mov r2, %[cpsr]           \n\t"
-                         "push {r2}                 \n\t" // Fake xPSR
-                         "push {r1}                 \n\t" // PC target addr
-                         "push {r0}                 \n\t" // Fake LR
-                         "push {r0}                 \n\t" // Fake R12
-                         "push {r0}                 \n\t" // Fake R3
-                         "push {r0}                 \n\t" // Fake R2
-                         "push {r0}                 \n\t" // Fake R1
-                         "push {r0}                 \n\t" // Fake R0
-                         "mov lr, %[exc_return]     \n\t"
-                         "bx lr"
-                         :
-                         : [stack_top] "r" (STACK_TOP),
-                           [target_addr] "r" (target),
-                           [exc_return] "r" (EXC_RETURN),
-                           [cpsr] "r" (DEFAULT_CPSR)
-                         : "r0", "r1", "r2");
+			nvic_sys_reset();			
 #endif
             /* Can't happen. */
             ASSERT_FAULT(0);