Quality RTOS & Embedded Software

 Real time embedded FreeRTOS RSS feed 
Real time embedded FreeRTOS mailing list 
Quick Start Supported MCUs PDF Books Trace Tools Ecosystem TCP & FAT Training


Unscheduled Scheduler Stoppage

Posted by John W. on May 16, 2006

After my target runs for awhile - I get a stoppage:

My call stack looks like this:


In main:

// shouldn't get past this point unless a task calls vTaskEndScheduler()

// Note - I have a breakpoint on this first NOOP but it doesn't stop there

while (1) {
// I have a breakpoint on the 2nd NOOP (just above) and the debugger stops here.

// turn Debug LED's on:
asm("bis.b #0x80,&0x1d");
asm("bis.b #0x01,&0x1d");

I run the Idle Hook as well - this (crash) doesn't always happen either - but I assume all of my targets will eventually fail.

What are some reasons this can happen? I know this may seem a bit nebulous - but the Scheduler is exiting (even though the vTaskEndScheduler() function) - isn't being called.

It seems that somehow the return address from the
vTaskStartScheduler(); call is getting popped into the PC and executed - or at least an address+2 or something.

From my linker map file:

Relative segment, address: 3082 - 3085 (0x4 bytes), align: 1
Segment part 5. Intra module refs: pvPortMalloc
===== =======
xEnd 3082

I'm using heap_2.c as my memory manager:

/* xEnd is used to mark the end of the list of free blocks. */

I'm also saying that the IdleTask & Hook should yield - it seems this problem may be occurring during that.

Thanks In Advance,
John W.

RE: Unscheduled Scheduler Stoppage

Posted by Nobody/Anonymous on May 16, 2006
I understand not the sentense "I'm also saying that the IdleTask & Hook should yield". The idle task must always be in a ready state and not blocked so just yield must be ok. Sorry to state obvious but sometimes it can help. Otherwise is the idle task stack causing a problem under some interrupt conditions?

RE: Unscheduled Scheduler Stoppage

Posted by John W. on May 16, 2006
Idle task doesn't block - correct.

I think the Idle Task Stack may be causing a problem under some interrupt conditions - yes.


[ Back to the top ]    [ About FreeRTOS ]    [ Sitemap ]    [ ]

Copyright (C) 2004-2010 Richard Barry. Copyright (C) 2010-2016 Real Time Engineers Ltd.
Any and all data, files, source code, html content and documentation included in the FreeRTOSTM distribution or available on this site are the exclusive property of Real Time Engineers Ltd.. See the files license.txt (included in the distribution) and this copyright notice for more information. FreeRTOSTM and FreeRTOS.orgTM are trade marks of Real Time Engineers Ltd.

Latest News:

FreeRTOS V9.0.0 is now available for download.

Free TCP/IP and file system demos for the RTOS

Sponsored Links

⇓ Now With No Code Size Limit! ⇓
⇑ Free Download Without Registering ⇑

FreeRTOS Partners

ARM Connected RTOS partner for all ARM microcontroller cores

Renesas Electronics Gold Alliance RTOS Partner.jpg

Microchip Premier RTOS Partner

RTOS partner of NXP for all NXP ARM microcontrollers

Atmel RTOS partner supporting ARM Cortex-M3 and AVR32 microcontrollers

STMicro RTOS partner supporting ARM7, ARM Cortex-M3, ARM Cortex-M4 and ARM Cortex-M0

Xilinx Microblaze and Zynq partner

Silicon Labs low power RTOS partner

Altera RTOS partner for Nios II and Cortex-A9 SoC

Freescale Alliance RTOS Member supporting ARM and ColdFire microcontrollers

Infineon ARM Cortex-M microcontrollers

Texas Instruments MCU Developer Network RTOS partner for ARM and MSP430 microcontrollers

Cypress RTOS partner supporting ARM Cortex-M3

Fujitsu RTOS partner supporting ARM Cortex-M3 and FM3

Microsemi (previously Actel) RTOS partner supporting ARM Cortex-M3

Atollic Partner

IAR Partner

Keil ARM Partner

Embedded Artists