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




Loading

data abort on AT91SAM7X256

Posted by Joanah on June 11, 2010
Hi,

I am new to FreeRTOS and I try to get my program run, but sometimes my debugger halts at line 161 in boot.s which says:

__dabt: b     .                         /* data abort


What does that mean? What could be the problem?

RE: data abort on AT91SAM7X256

Posted by Richard Damon on June 11, 2010
While I am not familiar with this processor, normally a data abort comes from accessing memory in a way you shouldn't. Some possible causes that are FreeRTOS related would be accessing a handle that hasn't been initialized, or whose initialization failed (and is thus null).

RE: data abort on AT91SAM7X256

Posted by pbeamtn on June 17, 2010
Been dealing with data aborts myself. It really does not have anything necessarily to do with FreeRTOS. Ideally, you would create a handler for this exception, which makes it easier to detect where the trouble is. What it means is that you have attempted to access memory that is invalid. Things like reading from a location where there is no memory, or trying to read data that is not aligned. For example, to read a 32 bit value, you have to be reading from an address on a 4 byte boundary.

Make sure you are not using a mutex or queue that has not been initialized. I think that may also cause this problem.

I usually set a break point and start hunting for the routine that causes this. It can be not much fun, but when you find it, look at your pointers or any other memory accesses to make sure the addresses are real memory, and then make sure that the alignment of what you are accessing is correct.

RE: data abort on AT91SAM7X256

Posted by avi asaf on June 19, 2010
i am familiar with this kind of problems, please check R14 register , in some cases its points the program address that point to the data abort.

please read at the ATMEL programming manual


[ 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