From 2ed8667f1822221141828804eb9e7fb1803a53fc Mon Sep 17 00:00:00 2001
From: Conor Patrick <conorpp94@gmail.com>
Date: Wed, 6 Feb 2019 17:55:27 -0500
Subject: [PATCH] immedately change clock rate to load data sections faster

---
 targets/stm32l432/src/startup_stm32l432xx.s | 55 +++++++++++----------
 targets/stm32l432/src/system_stm32l4xx.c    |  3 ++
 2 files changed, 31 insertions(+), 27 deletions(-)

diff --git a/targets/stm32l432/src/startup_stm32l432xx.s b/targets/stm32l432/src/startup_stm32l432xx.s
index 32d257f..7599702 100644
--- a/targets/stm32l432/src/startup_stm32l432xx.s
+++ b/targets/stm32l432/src/startup_stm32l432xx.s
@@ -7,7 +7,7 @@
   *                - Set the initial SP
   *                - Set the initial PC == Reset_Handler,
   *                - Set the vector table entries with the exceptions ISR address,
-  *                - Configure the clock system  
+  *                - Configure the clock system
   *                - Branches to main in the C library (which eventually
   *                  calls main()).
   *            After Reset the Cortex-M4 processor is in Thread mode,
@@ -79,6 +79,8 @@ Reset_Handler:
   ldr   sp, =_estack    /* Atollic update: set stack pointer */
 
 /* Copy the data segment initializers from flash to SRAM */
+/* Call the clock system intitialization function.*/
+    bl  SystemInit
   movs	r1, #0
   b	LoopCopyDataInit
 
@@ -106,8 +108,7 @@ LoopFillZerobss:
 	cmp	r2, r3
 	bcc	FillZerobss
 
-/* Call the clock system intitialization function.*/
-    bl  SystemInit
+
 /* Call static constructors */
     bl __libc_init_array
 /* Call the application's entry point.*/
@@ -115,7 +116,7 @@ LoopFillZerobss:
 
 LoopForever:
     b LoopForever
-    
+
 .size	Reset_Handler, .-Reset_Handler
 
 /**
@@ -414,49 +415,49 @@ g_pfnVectors:
 
 	.weak	COMP_IRQHandler
 	.thumb_set COMP_IRQHandler,Default_Handler
-	
+
 	.weak	LPTIM1_IRQHandler
 	.thumb_set LPTIM1_IRQHandler,Default_Handler
-	
+
 	.weak	LPTIM2_IRQHandler
-	.thumb_set LPTIM2_IRQHandler,Default_Handler	
-	
+	.thumb_set LPTIM2_IRQHandler,Default_Handler
+
 	.weak	USB_IRQHandler
-	.thumb_set USB_IRQHandler,Default_Handler	
-	
+	.thumb_set USB_IRQHandler,Default_Handler
+
 	.weak	DMA2_Channel6_IRQHandler
-	.thumb_set DMA2_Channel6_IRQHandler,Default_Handler	
-	
+	.thumb_set DMA2_Channel6_IRQHandler,Default_Handler
+
 	.weak	DMA2_Channel7_IRQHandler
-	.thumb_set DMA2_Channel7_IRQHandler,Default_Handler	
-	
+	.thumb_set DMA2_Channel7_IRQHandler,Default_Handler
+
 	.weak	LPUART1_IRQHandler
-	.thumb_set LPUART1_IRQHandler,Default_Handler	
-	
+	.thumb_set LPUART1_IRQHandler,Default_Handler
+
 	.weak	QUADSPI_IRQHandler
-	.thumb_set QUADSPI_IRQHandler,Default_Handler	
-	
+	.thumb_set QUADSPI_IRQHandler,Default_Handler
+
 	.weak	I2C3_EV_IRQHandler
-	.thumb_set I2C3_EV_IRQHandler,Default_Handler	
-	
+	.thumb_set I2C3_EV_IRQHandler,Default_Handler
+
 	.weak	I2C3_ER_IRQHandler
-	.thumb_set I2C3_ER_IRQHandler,Default_Handler	
-	
+	.thumb_set I2C3_ER_IRQHandler,Default_Handler
+
 	.weak	SAI1_IRQHandler
 	.thumb_set SAI1_IRQHandler,Default_Handler
-	
+
 	.weak	SWPMI1_IRQHandler
 	.thumb_set SWPMI1_IRQHandler,Default_Handler
-	
+
 	.weak	TSC_IRQHandler
 	.thumb_set TSC_IRQHandler,Default_Handler
-	
+
 	.weak	RNG_IRQHandler
 	.thumb_set RNG_IRQHandler,Default_Handler
-	
+
 	.weak	FPU_IRQHandler
 	.thumb_set FPU_IRQHandler,Default_Handler
-	
+
 	.weak	CRS_IRQHandler
 	.thumb_set CRS_IRQHandler,Default_Handler
 /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
diff --git a/targets/stm32l432/src/system_stm32l4xx.c b/targets/stm32l432/src/system_stm32l4xx.c
index 44f5432..bb12cc3 100644
--- a/targets/stm32l432/src/system_stm32l4xx.c
+++ b/targets/stm32l432/src/system_stm32l4xx.c
@@ -106,6 +106,7 @@
   */
 
 #include "stm32l4xx.h"
+#include "init.h"
 
 #if !defined  (HSE_VALUE)
   #define HSE_VALUE    8000000U  /*!< Value of the External oscillator in Hz */
@@ -219,6 +220,8 @@ void SystemInit(void)
   /* Disable all interrupts */
   RCC->CIER = 0x00000000U;
 
+  SystemClock_Config_LF();
+
 }
 
 /**