DM: fix worst bug in entire world

Author: deanm1278

cores/arduino/startup.c

@@ -50,6 +50,7 @@
 
 void SystemInit( void )
 {
+
 //***************** SAMD51 ************************//
 #if defined(__SAMD51__)
   NVMCTRL->CTRLA.reg |= NVMCTRL_CTRLA_RWS(0);
@@ -97,6 +98,10 @@ void SystemInit( void )
 	* 4) Enable DFLL48M clock
 	*/
 
+  while ( GCLK->SYNCBUSY.reg & GCLK_SYNCBUSY_GENCTRL0 ){
+    /* Wait for synchronization */
+  }
+
 	/* DFLL Configuration in Open Loop mode */
 
 	OSCCTRL->DFLLCTRLA.reg = 0;
@@ -203,6 +208,8 @@ void SystemInit( void )
   /*---------------------------------------------------------------------
   * Set up main clock
   */
+
+
 	GCLK->GENCTRL[GENERIC_CLOCK_GENERATOR_MAIN].reg = GCLK_GENCTRL_SRC(MAIN_CLOCK_SOURCE) |
 					GCLK_GENCTRL_IDC |
 					//GCLK_GENCTRL_OE |

platform.txt

@@ -33,7 +33,7 @@ compiler.warning_flags.all=-Wall -Wextra
 
 compiler.path={runtime.tools.arm-none-eabi-gcc.path}/bin/
 compiler.c.cmd=arm-none-eabi-gcc
-compiler.c.flags=-mcpu={build.mcu} -mthumb -c -g -O0 {compiler.warning_flags} -std=gnu11 -ffunction-sections -fdata-sections -nostdlib --param max-inline-insns-single=500 -MMD 
+compiler.c.flags=-mcpu={build.mcu} -mthumb -c -g -Os {compiler.warning_flags} -std=gnu11 -ffunction-sections -fdata-sections -nostdlib --param max-inline-insns-single=500 -MMD 
 compiler.c.elf.cmd=arm-none-eabi-gcc
 compiler.c.elf.flags=-Os -Wl,--gc-sections -save-temps
 compiler.S.cmd=arm-none-eabi-gcc