Changing the default start address

[Jiri Gaisler]

On 09/17/2013 10:33 AM, Mohammed Khoory wrote:
> I would like to shift the entire code, including the start code, to a
> specific location. I assume the start code is located at the default
> location, correct? Therefore, after the shift, the start code should be
> located at the "specific location"

The -Ttext option works fine on leon3 as long as you stay within the
SRAM/SDRAM area (0x40000000 - 0x80000000), and actually have memory
implemented on the new start address. Also note that the start address
must be aligned on a 4 Kbyte boundary to properly locate the trap table.

Jiri.

> 
> Generally, I want to shift the entire code by an offset, such that anything
> that was at ADDRESS is now at ADDRESS+OFFSET, if that makes sense. 
> 
>> -----Original Message-----
>> From: rtems-users-bounces at rtems.org [mailto:rtems-users-
>> bounces at rtems.org] On Behalf Of Sebastian Huber
>> Sent: Tuesday, September 17, 2013 4:29 PM
>> To: rtems-users at rtems.org
>> Subject: Re: Changing the default start address
>>
>> Hello Mohammed,
>>
>> do you want to move the start code to a different memory location or do you
>> want to simply change the entry symbol of the ELF file?
>>
>> On 2013-09-17 02:54, Mohammed Khoory wrote:
>>> Hi,
>>>
>>> For certain hardware-related reasons, I need to change the starting
>>> address of my RTEMS executable to something slightly different than
>>> what the BSP specifies. For what I understood, this should be
>>> achievable by passing -Ttext=<address> to the linker. After doing
>>> that, I can see that all the relevant symbols (like start and others)
>>> have shifted to the new address if I check with readelf.
>>> Unfortunately, when I try to run it, the executable fails at a very early
> point
>> due to an undefined trap.
>>>
>>> Is there anything else I should consider or change when changing the
>>> start address of the executable? I tried searching the BSP headers for
>>> the old address but I couldn't find anything useful.
>>>
>>> I'm using the LEON3 BSP (sparc). The default start address is 0x40000000.
>>>
>>> Thanks,
>>> Mohammed Khoory
>>>
>>> _______________________________________________
>>> rtems-users mailing list
>>> rtems-users at rtems.org
>>> http://www.rtems.org/mailman/listinfo/rtems-users
>>>
>>
>>
>> --
>> Sebastian Huber, embedded brains GmbH
>>
>> Address : Dornierstr. 4, D-82178 Puchheim, Germany
>> Phone   : +49 89 189 47 41-16
>> Fax     : +49 89 189 47 41-09
>> E-Mail  : sebastian.huber at embedded-brains.de
>> PGP     : Public key available on request.
>>
>> Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.
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> 
> 
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