[ECOS] TCP/IP on Olimex - sam7-ex256

[ECOS] TCP/IP on Olimex - sam7-ex256

[Ormund Williams]

Hi All

Has anyone got any of the tcp/ip stacks running on the above dev board?
When I try to compile any of the examples it fails to link with the
error: "section .bss is not within region ram".

Is the a way to reduce the amount of ram required? Any tips welcomed.

__
Ormund



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Re: [ECOS] TCP/IP on Olimex - sam7-ex256

[Andrew Lunn]

On Thu, May 08, 2008 at 02:23:28PM -0400, Ormund Williams wrote:
> Hi All
> 
> Has anyone got any of the tcp/ip stacks running on the above dev board?
> When I try to compile any of the examples it fails to link with the
> error: "section .bss is not within region ram".
> 
> Is the a way to reduce the amount of ram required? Any tips welcomed.

I know of people who have used lwip on this device. 

The LWIP stack has lots of configuration options which will affect
memory usage. Do you need TCP? No, then remove it. How many TCP
connections do you need? Change CYGNUM_LWIP_MEMP_NUM_TCP_PCB etc.

What i sometimes do in situations like this is edit the linker script,
target.ld, to give it more memory than there actually is, just so that
it will link. Then use arm-elf-nm or arm-elf-objdump --syms to look at
the size of the symbols. Find the big ones and try to optimize
them. Often the symbols causing the problem are not where you expect
them.

        Andrew

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Re: [ECOS] TCP/IP on Olimex - sam7-ex256

[Ormund Williams]

On Sun, 2008-05-11 at 15:12 +0200, Andrew Lunn wrote:
> I know of people who have used lwip on this device. 
> 
> The LWIP stack has lots of configuration options which will affect
> memory usage. Do you need TCP? No, then remove it. How many TCP
> connections do you need? Change CYGNUM_LWIP_MEMP_NUM_TCP_PCB etc.
> 
Actually I don't need TCP, UDP is enough.  I haven't used eCos in a
while so I'm still clearing the cobwebs.  I know lwIP works on this
device I ran the FreeRTOS demo so I'll dig in.

> What i sometimes do in situations like this is edit the linker script,
> target.ld, to give it more memory than there actually is, just so that
> it will link. Then use arm-elf-nm or arm-elf-objdump --syms to look at
> the size of the symbols. Find the big ones and try to optimize
> them. Often the symbols causing the problem are not where you expect
> them.
Great tip, I'll try that.

__
Ormund



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