[ECOS] Memory problems (layout ...)

[ECOS] Memory problems (layout ...)

[Matthieu.GIRARDIN]

Hello guys !

1) 

After having read your doc lines about memory mapping, I tried to change my
files mlt_* ...
I would like to have my RAM (2Mo) at addr "0" and my ROM (4Mo) at addr "4
000 000" .
So I tried to modify my rom.mlt. But it didn't generate a good rom.ldi and
rom.h ...
How can I do ? 
I tried then to remove my rom.h rom.ldi, I believed that your makefile would
generate them again
but it didn't work. 
In fact to sum up, with modified rom.mlt, the system didn't generate good
rom.ldi and rom.h so my target.ld isn't right !

2)

Another question: will I use after the previous step, a tool to transfer my
data section to rom from ram in order to flash them to my board ? Because
I've seen
in my nm file (powerpc-eabi-nm toto.elf) that, even if my mapping isn't
completely right (previous question), my data section is in RAM (addr 0 and
more) and not in ROM (addr 4 000 000 and more)

Please help me ...

Thanks by advance.

Matthieu

NB: when I said rom.mlt, you should understand mlt_..._rom.mlt. It was
shorter to write ... ;-)

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RE: [ECOS] Memory problems (layout ...)

[James Yates]

Hi Matthieu,

1)  It is my understanding that the .mlt file is produced by the memory configuration tool present in v1 of the Configuration Tool only and not in the latest v2 tool. You can ignore the .mlt file and simply modify the .h and .ldi files to provide the correct memory layout. They are reasonably clear to undestand. The .h file simply provides some defines and the .ldi file is a standard gnu linker script. See the documentation on ld if you have problems with this.

2) In the linker script you can specify the data section to be placed in rom but then moved to RAM upon execution using the AT_ADDR command. Check the ld documentation. A good starting point would be a rom.ldi file already in eCos. Since any code placed in rom will still have to have the data section in RAM upon execution, this will already be covered.

	Hope this helps.

		James Yates

-----Original Message-----
From: Matthieu.GIRARDIN@fr.thalesgroup.com
[mailto:Matthieu.GIRARDIN@fr.thalesgroup.com]
Sent: 10 October 2003 07:32
To: ecos-discuss@sources.redhat.com
Subject: [ECOS] Memory problems (layout ...)



Hello guys !

1) 

After having read your doc lines about memory mapping, I tried to change my
files mlt_* ...
I would like to have my RAM (2Mo) at addr "0" and my ROM (4Mo) at addr "4
000 000" .
So I tried to modify my rom.mlt. But it didn't generate a good rom.ldi and
rom.h ...
How can I do ? 
I tried then to remove my rom.h rom.ldi, I believed that your makefile would
generate them again
but it didn't work. 
In fact to sum up, with modified rom.mlt, the system didn't generate good
rom.ldi and rom.h so my target.ld isn't right !

2)

Another question: will I use after the previous step, a tool to transfer my
data section to rom from ram in order to flash them to my board ? Because
I've seen
in my nm file (powerpc-eabi-nm toto.elf) that, even if my mapping isn't
completely right (previous question), my data section is in RAM (addr 0 and
more) and not in ROM (addr 4 000 000 and more)

Please help me ...

Thanks by advance.

Matthieu

NB: when I said rom.mlt, you should understand mlt_..._rom.mlt. It was
shorter to write ... ;-)

-- 
Before posting, please read the FAQ: http://sources.redhat.com/fom/ecos
and search the list archive: http://sources.redhat.com/ml/ecos-discuss


--
Before posting, please read the FAQ: http://sources.redhat.com/fom/ecos
and search the list archive: http://sources.redhat.com/ml/ecos-discuss