[uClinux-dev] Strange ARM behaviour....

Kostas Hatzis khatzis at patras.atmel.com
Thu Nov 22 02:46:24 EST 2001


1) Check out that your memory is stable at 0. 
2) Try rewriting the assembly your own way. 

Kostas

Dr Kostas Hatzis
Senior Firmware Engineer
ATMEL HELLAS S.A., Multimedia & Communications Group
Patras Science Park, Stadiou Street
Platani 26 500
Patras, Greece
Tel: +30 61 961228
Fax: +30 61 961221
Email: khatzis at patras.atmel.com
http://www.atmel.com
----- Original Message ----- 
From: "Fabrice Gautier" <Fabrice_Gautier at sdesigns.com>
To: "Uclinux-Dev (E-mail)" <uclinux-dev at uclinux.org>
Sent: Wednesday, November 21, 2001 10:35 PM
Subject: [uClinux-dev] Strange ARM behaviour....


> Hi,
> 
> I'm using an EB63 atmel board, and i've some problem with the exception
> vector setup.
> 
> The setup is done in arch/armnommu/entry-armv.S in the __trap_init function.
> 
> the function copy this vectors:
> 
> .LCvectors: swi SYS_ERROR0
> b __real_stubs_start + (vector_undefinstr -
> __stubs_start)
> ldr pc, __real_stubs_start + (.LCvswi - __stubs_start)
> b __real_stubs_start + (vector_prefetch -
> __stubs_start)
> b __real_stubs_start + (vector_data - __stubs_start)
> b __real_stubs_start + (vector_addrexcptn -
> __stubs_start)
> b __real_stubs_start + (vector_IRQ - __stubs_start)
> b __real_stubs_start + (vector_FIQ - __stubs_start)
> 
> with these 2 instructions :
> 
> ldmia r1, {r1, r2, r3, r4, r5, r6, ip, lr}
> stmia r0, {r1, r2, r3, r4, r5, r6, ip, lr}
> 
> (ldm = load multiple, stm =store multiple) with r1 pointing to the vectors
> above and r0 pointing to 0.
> 
> I use the ARM debugger with multiICE to see what's happening here. And what
> happenging is that the stmia instruction doesn't store all the registers
> correctly. The adresses 0, 4, 0xc and 0x10 are not updated byt the
> instruction as they should. If I point r0 to any other adresse it works ok.
> Just this 4 adresses are not updated. I can update then by hand in the
> debugger but the code doesn't semm to ba able to do it.
> 
> Is there anybody who have an idea what's causing this behaviour ???
> 
> Thanks
> 
> 
> -- 
> Fabrice Gautier
> Software Engineer, Sigma Designs
> Fabrice_Gautier at sdesigns.com
> 
> This message resent by the uclinux-dev at uclinux.org list server http://www.uClinux.org/

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