Re: Different section placement for kernel and application

Martin Rösch <martin.roesch <at> neratec.com> writes:

> 
> Hi,
> 
> On 2011-01-28, Grant Edwards <grant.b.edwards <at> gmail.com> wrote:
> > I'm curious why you want to do this. What benefit does it provide?
> 
> I have to link a C++ Application to eCos (with FreeBSD Stack and uSTL) on 
a STM32 derived board. 
> The footprint is to big to run it from the internal flash. So we decided 
to run it from external RAM. 
> Unfortunately the performance regarding IRQ handling of a RAM Application 
is too bad:
> Using the timers test from the STM32 variant HAL, I've set only TIM1 
active and then varied the update
> interrupt period. It turned out, that with a period of 20msec. the IRQ 
handler run into an Assertion in
> the post_dsr() function:
> ASSERT FAIL: <5>intr.cxx[292]void Cyg_Interrupt::post_dsr() DSR list is 
not empty but its head is 0
> 
> Doing the same test with a ROM Application, the period can be lowered to 
50usec.
> 
> So I'm trying to move the eCos library that contains the ISRs, DSRs etc. 
to the Internal Flash while keeping
> the rest of the application (that has no ISRs and DSRs) still in the 
external RAM.
> 
> I hope this Setup will improve the IRQ handling.
> 
> Greetings,
> 
> Martin
> 

Hi Martin,

I am about to start a new project using ecos (need to posix os with tcp/ip 
stack) and I want to know roughly the footprint of the os.
Do you know how much does ecos with tcp/ip stack consume?

Thanks,
Badreddine


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