diff --git a/startup_stm32f042x6.s b/startup_stm32f042x6.s
--- a/startup_stm32f042x6.s
+++ b/startup_stm32f042x6.s
@@ -84,6 +84,7 @@ Reset_Handler:
 
 /* Boot into bootloader */
 Reboot_Loader:
+  b Reboot_Loader
   LDR     R0, =0x40021018 // RCC_APB2ENR (+0x18)
   LDR     R1, =0x00000001 // ENABLE SYSCFG CLOCK
   STR     R1, [R0, #0]
@@ -91,12 +92,13 @@ Reboot_Loader:
   LDR     R1, =0x00000001 // MAP ROM AT ZERO
   STR     R1, [R0, #0]
   //                LDR     R0, =0x1FFFEC00 ; ROM BASE (STM32F03x)
-  LDR     R0, =0x1FFFC400 // ROM BASE (STM32F04x)
+  LDR     R0, =0x1FFFC800 // ROM BASE (STM32F04x)
   //                LDR     R0, =0x1FFFEC00 ; ROM BASE (STM32F05x)
   //                LDR     R0, =0x1FFFC800 ; ROM BASE (STM32F07x)
   //                LDR     R0, =0x1FFFD800 ; ROM BASE (STM32F09x)
   LDR     R1, [R0, #0]    // SP @ +0
   MOV     SP, R1
+
   LDR     R0, [R0, #4]    // PC @ +4
   BX      R0