bootloader: FreeRTOS app now boots properly

The issue was the SysTick timer, which was configured by the bootloader to blink the backlight LEDs, but was not de-configured before booting to the application. Without the SysTick timer de-configured, the FreeRTOS tick timer, which relies on the SysTick timer, fired before FreeRTOS could be properly configured. Since the FreeRTOS SysTick handler contains some OS-specific functions and data, the fact that these were not initialized probably led to a segfault. This issue was fixed in boot.c, by de-configuring the SysTick timer.

bootloader: FreeRTOS app now boots properly
The issue was the SysTick timer, which was configured by the bootloader to blink the backlight LEDs, but was not de-configured before booting to the application. Without the SysTick timer de-configured, the FreeRTOS tick timer, which relies on the SysTick timer, fired before FreeRTOS could be properly configured. Since the FreeRTOS SysTick handler contains some OS-specific functions and data, the fact that these were not initialized probably led to a segfault. This issue was fixed in boot.c, by de-configuring the SysTick timer.
6e997732 · Theodor-Adrian Stana · 4c0752ca · 6e997732 · 6e997732
Commit 6e997732 authored Sep 23, 2014 by Theodor-Adrian Stana
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Showing with 8 additions and 2 deletions

boot.c sw/bootloader-an0042/boot.c +6 -0

main.c sw/bootloader-an0042/main.c +2 -2

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--- a/sw/bootloader-an0042/boot.c
+++ b/sw/bootloader-an0042/boot.c
@@ -153,6 +153,12 @@ void BOOT_boot(void)
  CMU->LFCLKSEL     = _CMU_LFCLKSEL_RESETVALUE;
  CMU->LFACLKEN0    = _CMU_LFACLKEN0_RESETVALUE;

+  /*
+   * Disable SysTick timer (bits TICKINT and ENABLE in SysTick.CTRL -- see
+   * EFM32 Cortex-M3 Reference Manual)
+   */
+  SysTick->CTRL &= ~0x3;
+
  /* Set new vector table pointer */
  SCB->VTOR = (uint32_t)BOOTLOADER_SIZE;


--- a/sw/bootloader-an0042/main.c
+++ b/sw/bootloader-an0042/main.c
@@ -145,8 +145,8 @@ int main(void)
  int j;

 #if !defined( SIMULATE_SWDCLK_PIN_HI )
-  /* Listen button BR and enter bootloader mode if pressed */
-  while (GPIO_PinInGet(gpioPortA, 8))
+  /* Listen button TL and enter bootloader mode if pressed */
+  while (GPIO_PinInGet(gpioPortC, 7))
  {
    USB_PUTS( "SWDCLK is low\r\n" );