Réf : RE: Init of the memory by RTEMS

Leonard Bise leonard.bise at syderal.ch
Thu Dec 10 09:22:35 UTC 2009


Thanks for your answer but :

40000000 g       *ABS*  00000000 RAM_START
001e0000 g       *ABS*  00000000 RAM_SIZE
401e0000 g       *ABS*  00000000 RAM_END

40000000 g       *ABS*  00000000 _RAM_START
001e0000 g       *ABS*  00000000 _RAM_SIZE
401e0000 g       *ABS*  00000000 _RAM_END

This is really puzzling, how is it possible to clear data that it does not 
know about ?

Léonard.




"Zandin Johan" <johan.zandin at ruag.com> 
10.12.2009 10:11

A
"Leonard Bise" <leonard.bise at syderal.ch>
cc
<rtems-users at rtems.org>
Objet
RE: Init of the memory by RTEMS






Hi!

I'm not sure that it's sufficient to update the MEMORY
structure. You may also have to modify some of these:

RAM_START
RAM_SIZE
RAM_END
_RAM_START
_RAM_SIZE
_RAM_END

Best regards
/Johan Zandin


>-----Original Message-----
>From: rtems-users-bounces at rtems.org 
>[mailto:rtems-users-bounces at rtems.org] On Behalf Of Leonard Bise
>Sent: den 10 december 2009 08:38
>To: Joel Sherrill
>Cc: rtems-users at rtems.org
>Subject: Réf : Re: Réf : Re: Réf : Re: Init of the memory by RTEMS
>
>
>I tried this methode but surprinsingly the memory in this area 
>STILL gets erased. I don't know by what  and it does not make 
>any sense either. 
>
>401e0000 g       *ABS*        00000000 _RAM_END 
>
>That seems correct but something is STILL clearing that damn memory ! 
>
>I'm seriously lost now.. 
>
>Léonard. 
>
>
>
>
>
>Joel Sherrill <joel.sherrill at oarcorp.com> 
>
>09.12.2009 20:28 A
>Aleix Conchillo Flaqué <aconchillo at ice.csic.es> 
>cc
>Leonard Bise <leonard.bise at syderal.ch>, 
>"rtems-users at rtems.org" <rtems-users at rtems.org> 
>Objet
>Re: Réf : Re: Réf : Re: Init of the memory by RTEMS
>
> 
>
>
>
>
>On 12/09/2009 10:24 AM, Aleix Conchillo Flaqué wrote:
>> Why don't you just change the start of your Application? For example:
>>
>>
>> MEMORY
>> {
>>   ram     : ORIGIN = 0x40020000, LENGTH = 2M - 128 K
>> }
>>
>> RTEMS will not modify anything from 0x40000000 to 0x4001FFFF.
>>
>Or simply leave ORIGIN alone and subtract 128K from the LENGTH.
>Either way works.  But you can't tell RTEMS about it. :)
>
>--joel
>>
>> On Wed, Dec 9, 2009 at 14:26, Leonard Bise <leonard.bise at syderal.ch 
>> <mailto:leonard.bise at syderal.ch>> wrote:
>>
>>
>>     Thanks for your answer Joel.
>>
>>     We are using the 4.6 version of RTEMS so I guess the memory must
>>     be cleared.
>>
>>     I already use a customized linkcmds file in this application, to
>>     specify various sections and other stuff.
>>
>>     Thats what I modified for my RAM size :
>>
>>     RAM_SIZE   = 2M ;
>>
>>     EEPROM_SIZe = 512K ;
>>
>>     PROM_SIZE        = 64K ;
>>
>>     RAM_END = RAM_START + RAM_SIZE;
>>
>>     MEMORY
>>     {
>>       rom     : ORIGIN = 0x00000000, LENGTH = 64K
>>       ram     : ORIGIN = 0x40000000, LENGTH = 2M
>>       eeprom  : ORIGIN = 0x60000000, LENGTH = 512K
>>     }
>>
>>     >If you do not reserve the memory area out of the linkcmds, then
>>     >it is likely to be used for some other purpose and overwritten.
>>
>>     How can I reserve memory ? I tried creating a section like this :
>>
>>       sCCA_Main 0x401E7000: {
>>         *(sCCA_Main)
>>        } > ram
>>
>>     then my var in the code looks like this :
>>
>>     uint32 PkgHW_CCA_main __attribute__ (( section ( 
>"sCCA_Main" ) ) ) ;
>>
>>     But this does not work, the data I place in 0x401E7000 before
>>     starting execution of my RTEMS apps is overwritten by 0.
>>     Hope you can help.
>>
>>     Léonard.
>>
>>
>>
>>
>>     *Joel Sherrill <joel.sherrill at oarcorp.com
>>     < <mailto:leonard.bise at syderal.ch> 
>mailto:joel.sherrill at oarcorp.com>>*
>>
>>     09.12.2009 14:16
>>
>> 
>>     A
>>                      Leonard Bise <leonard.bise at syderal.ch
>>     < <mailto:joel.sherrill at oarcorp.com> 
>mailto:leonard.bise at syderal.ch>>
>>     cc
>>                      Sebastian Huber 
><sebastian.huber at embedded-brains.de
>>     < <mailto:leonard.bise at syderal.ch> 
>mailto:sebastian.huber at embedded-brains.de>>,
>>     "rtems-users at rtems.org < 
><mailto:sebastian.huber at embedded-brains.de> 
>mailto:rtems-users at rtems.org>"
>>     <rtems-users at rtems.org < <mailto:rtems-users at rtems.org> 
>mailto:rtems-users at rtems.org>>
>>     Objet
>>                      Re: Réf : Re: Init of the memory by RTEMS
>>
>>
>>
>> 
>>
>>
>>
>>
>>
>>     On 12/09/2009 06:41 AM, Leonard Bise wrote:
>>     >
>>     > I forgot to mention it.
>>     >
>>     > I'm using RTEMS for the LEON2 platform.
>>     >
>>     Version?
>>     > Also I'm not too sure how to know the address of the workspace
>>     or heap?
>>     >
>>     They are next to each other and the linkcmds and symbol
>>     table from your application should give the information.
>>
>>     Where did  you override the RAM size?  The linkcmds
>>     has this:
>>
>>     MEMORY
>>     {
>>       rom     : ORIGIN = 0x00000000, LENGTH = 256M
>>       ram     : ORIGIN = 0x40000000, LENGTH = 1024M
>>     }
>>
>>     And the start.S zeroes out the BSS from "_edata"
>>     to "_end".
>>
>>     The addresses you mentioned will be part of the
>>     unused memory from after the bss until the end of ram
>>     and since you didn't tell the linkcmds or RTEMS about them,
>>     they will be put in either the Workspace or C Program Heap
>>     and used by something.
>>
>>
>>
>>     --joel
>>
>>     > Léonard.
>>     >
>>     >
>>     >
>>     > *Sebastian Huber <sebastian.huber at embedded-brains.de
>>     < <mailto:rtems-users at rtems.org> 
>mailto:sebastian.huber at embedded-brains.de>>*
>>     >
>>     > 09.12.2009 11:31
>>     >
>>     >
>>     > A
>>     >                  Leonard Bise <leonard.bise at syderal.ch
>>     < <mailto:sebastian.huber at embedded-brains.de> 
>mailto:leonard.bise at syderal.ch>>
>>     > cc
>>     > rtems-users at rtems.org < 
><mailto:leonard.bise at syderal.ch> mailto:rtems-users at rtems.org>
>>     > Objet
>>     >                  Re: Init of the memory by RTEMS
>>     >
>>     >
>>     >
>>     >
>>     >
>>     >
>>     >
>>     >
>>     >
>>     > Hi,
>>     >
>>     > which BSP do you use? Is the memory address 0x401E7000 
>part of the
>>     > workspace or
>>     > heap?
>>     >
>>     > CU
>>     >
>>     > --
>>     > Sebastian Huber, embedded brains GmbH
>>     >
>>     > Address : Obere Lagerstr. 30, D-82178 Puchheim, Germany
>>     > Phone   : +49 89 18 90 80 79-6
>>     > Fax     : +49 89 18 90 80 79-9
>>     > E-Mail  : sebastian.huber at embedded-brains.de
>>     < <mailto:rtems-users at rtems.org> 
>mailto:sebastian.huber at embedded-brains.de>
>>     > PGP     : Public key available on request.
>>     >
>>     > Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des
>>     EHUG.
>>     >
>>
>>
>>
>>     _______________________________________________
>>     rtems-users mailing list
>>     rtems-users at rtems.org < 
><mailto:sebastian.huber at embedded-brains.de> 
>mailto:rtems-users at rtems.org>
>>     <mailto:rtems-users at rtems.org> 
>http://www.rtems.org/mailman/listinfo/rtems-users
>>
>>
>
>
>-- 
>Joel Sherrill, Ph.D.             Director of Research&  Development
>joel.sherrill at OARcorp.com        On-Line Applications Research
>Ask me about RTEMS: a free RTOS  Huntsville AL 35805
>   Support Available             (256) 722-9985
>
>
><http://www.rtems.org/mailman/listinfo/rtems-users> 
>
>

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