2011-01-06 04:52:30     537-Stamp - activating the mmu

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2011-01-06 04:52:30     537-Stamp - activating the mmu

Hermann Lorenz (GERMANY)

Message: 97231   

 

Hi,

 

I have a 537-Stamp board and I want to activate the memory protection unit.

 

I downloaded uClinux-kernel 2.6.28.10 and the toolchain 09r1.1-2.i386.

 

I wrote a little test program which starts at the adress 0 and sets alle the memory to zero. When I start this program on a kernel that is flashed on the board it all crashes down and I have to reset the board by pressing the reset button.

 

But when I compile the standard kernel configuration, there seems to be a watchdog that reboots the board after a couple of seconds. When I choose the kernel option to enable the memory protection unit, nothing changes. The watchdog still reboots the board and does not terminate the test program.

 

 

 

So there are a couple of questions:

 

    is my test program wrong?

    do I have to activate some other kernel options?

    do I expect a wrong behaviour?

    is it normal, that kernel can only be compiled by "make -i"? If enter only "make" it stops with some errors.

 

Hermann

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2011-01-06 10:22:52     Re: 537-Stamp - activating the mmu

Mike Frysinger (UNITED STATES)

Message: 97232   

 

please use 2010R1

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2011-01-08 06:34:39     Re: 537-Stamp - activating the mmu

Hermann Lorenz (GERMANY)

Message: 97272   

 

Thank you Mike.

 

I started testing the memory protection unit some months ago, when the 2010R1 was not availeable yet. With it it all seems to work fine and memory violations seem to be detected.

 

Does anyone have an idea, how I could corrupt the unprotected uClinux? I thought about changing something in the kernel structures like the process table or something that would show, that I corrupt the system without destroying it. But I have no idea how to get the adresses of the kernel structures and which would be the best to modify.

 

 

 

Hermann

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2011-01-08 10:27:53     Re: 537-Stamp - activating the mmu

Mike Frysinger (UNITED STATES)

Message: 97273   

 

look at the System.map file for addresses

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