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[FreeRTOS Home] [Live FreeRTOS Forum] [FAQ] [Archive Top] [August 2014 Threads] FreeRTOS Boot From Flash Exception Halted!Posted by mbcoteli on August 27, 2014 I am implementing a freertos scheduling tasks on the development board of ZC702. I would debug the code on the Xilinx SDK. I get no error. However, when I want it to boot from flash, after about 2-3 minutes, I get the following error "EXCEPTION HALTED!". Then the addresses for the fault address are displayed. Do you have any idea on the occuring problem ? It is the error log pushed from the FreeRTOS_ExHandler function on port.c.
FreeRTOS Boot From Flash Exception Halted!Posted by rtel on August 27, 2014 Sorry - I don't know why this would happen after two or three minutes. If it runs for that long then the interrupt vectors must be installed correctly. Have you tried the normal things like turning on stack overflow protection and defining configASSERT()?
Regards.
FreeRTOS Boot From Flash Exception Halted!Posted by mbcoteli on September 18, 2014 The problem occurs due to task management error. A task is used for the memcpy operations. It blocks the arm processor on a higher time than we expected. I need to implement DMA operations on Freertos to decrease the required time. There is an example code named as xdmapsexamplewintr14_2.c. When it is used on Freertos, dma operations aren't performed. It would be due to hardware implementations. Do you suggest any example implementations of DMA on Freertos ?
Thanks, Regards.
FreeRTOS Boot From Flash Exception Halted!Posted by rtel on September 18, 2014 I use DMA with FreeRTOS all the time - the normal rules apply - your DMA interrupt must be at or below the maximum system call interrupt priority if it uses the FreeRTOS API. Also if you are using a DMA then you effectively have multiple bus masters so if you are using caches you may need to flush the caches prior to each bus master accessing the effected RAM.
Also, which memcpy() are you using? The official FreeRTOS demo overrides the C library memcpy() because the C libraries implementation corrupts the floating point context (it uses floating point registers for their additional width as an optimisation).
Regards.
FreeRTOS Boot From Flash Exception Halted!Posted by mbcoteli on September 29, 2014 Thanks for your reply. I use the standard C function of memcpy. In which file FREERTOS overrides the standard memcpy function ?
For the DMA implementation, I have a question about the channels. Could I change the destination address after I start the DMA operation ? I need to restart the DMA operation in a while loop. It makes DMA only one time. When I change the destination address and restart it, it doesn't enter the Success state. Could you check the following situation?
Thanks.
while(1)
{
DmaCmd.BD.DstAddr = (u32) FirstRegionFrame;
Status= XDmaPsStart(DmaInst, 0, &DmaCmd,0);
if(Status != XSTSUCCESS) {
xilprintf("DMA Failurern");
}
else
{
xilprintf("DMA Region %xrn",*FirstRegionFrame);
}
}
FreeRTOS Boot From Flash Exception Halted!Posted by rtel on September 29, 2014
Thanks for your reply. I use the standard C function of memcpy. In which
file FREERTOS overrides the standard memcpy function ?
I think it is in the main.c file of the official demo. It is an
extremely basic and non-optimal implementation though - provided only to
get around the problem.
For the DMA implementation
Sorry we are unable to provide support specific to a chip's peripheral.
We support so many different chips, all of which have many peripherals
so it is not feasible. Besides which, this is a FreeRTOS support forum,
and most chip manufactures have their own support resources specific to
their parts.
Regards.
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