[ECOS] Preliminary questions on eCOS

[ECOS] Preliminary questions on eCOS

[JS Stoezel]

Hello,

I am interested in knowing more about eCOS. Our target CPU is a NEC
V53A. This is an Intel x86 compatible with limited RAM (1Mbytes) and
limited PROM (56k available for the OS). This is a 16-bit processor,
however it runs in 8-bit data bus as a mean to save power.

My first questions are:
- In minimal mode (eCOS kernel only)
	- What is the PROM footprint?
	- What is the RAM footprint? I understand this is dependent on
the number of threads running, message queues, dynamic memory
allocation. Let say we want to run 3 tasks, using 4 message queues each.

Same questions with File System Support.

Our processor was benchmarked at 1MIPS (Sorry I do not have any details
on the benchmark procedure, I do not know if this is Wheatstone,
Dhrystone or other).  How much overhead per context switch can we
expect?

Thanks,
Jean-Sebastien

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[ECOS] Re: Preliminary questions on eCOS

[Grant Edwards]

On 2007-03-20, JS Stoezel <js.stoezel@magellan.aero> wrote:

> I am interested in knowing more about eCOS. Our target CPU is a NEC
> V53A. This is an Intel x86 compatible with limited RAM (1Mbytes) and
> limited PROM (56k available for the OS). This is a 16-bit processor,

You can't run eCos on an 8086.  eCos requires gcc (not
available for 8086).  I think eCos assumes an int is at least
32 bits long, but I might be wrong about that.

-- 
Grant Edwards                   grante             Yow!  Yow! I like my new
                                  at               DENTIST...
                               visi.com            


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RE: [ECOS] Re: Preliminary questions on eCOS

[JS Stoezel]

Hello,

I see there is no tool chain for this type of processor (this is stated
here: http://ecos.sourceware.org/ecos/getstart.html). However I can
read: "Developers targeting one of the other architectures must build a
toolchain themselves at present. Full instructions for downloading
source code and building a toolchain are available.". Doesn't this mean
I can port eCOS to the tool chain I am using?

Thanks,
Jean-Sebastien 

> -----Original Message-----
> From: ecos-discuss-owner@ecos.sourceware.org 
> [mailto:ecos-discuss-owner@ecos.sourceware.org] On Behalf Of 
> Grant Edwards
> Sent: Tuesday, March 20, 2007 9:37 AM
> To: ecos-discuss@sources.redhat.com
> Subject: [ECOS] Re: Preliminary questions on eCOS
> 
> On 2007-03-20, JS Stoezel <js.stoezel@magellan.aero> wrote:
> 
> > I am interested in knowing more about eCOS. Our target CPU is a NEC 
> > V53A. This is an Intel x86 compatible with limited RAM 
> (1Mbytes) and 
> > limited PROM (56k available for the OS). This is a 16-bit processor,
> 
> You can't run eCos on an 8086.  eCos requires gcc (not 
> available for 8086).  I think eCos assumes an int is at least
> 32 bits long, but I might be wrong about that.
> 
> -- 
> Grant Edwards                   grante             Yow!  Yow! 
> I like my new
>                                   at               DENTIST...
>                                visi.com            
> 
> 
> --
> Before posting, please read the FAQ: 
> http://ecos.sourceware.org/fom/ecos
> and search the list archive: 
> http://ecos.sourceware.org/ml/ecos-discuss
> 
> 

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[ECOS] Re: Preliminary questions on eCOS

[Grant Edwards]

On 2007-03-20, JS Stoezel <js.stoezel@magellan.aero> wrote:

> I see there is no tool chain for this type of processor (this
> is stated here: http://ecos.sourceware.org/ecos/getstart.html). 
> However I can read: "Developers targeting one of the other
> architectures must build a toolchain themselves at present.
> Full instructions for downloading source code and building a
> toolchain are available.". Doesn't this mean I can port eCOS
> to the tool chain I am using?

It means that if you want to target an architecture for which
there aren't a pre-built gcc/binutils tool-chains, you have to
download the gcc/binutils sources and build a tool-chain.

eCos uses a number of gcc C and C++ extensions as well as some
rather unique binutils features. In theory you could port eCos
to another tool-chain, but it's going to be tough. People on
the mailing list have talked about attempting to do such a
port, but I don't think anybody has reported success.

I'd probably look at other RTOSes (FreeRTOS, XMK, uC/OS-II)
before I'd start thinking about porting eCos to a 16-bit
processor using a non-gcc tool-chain.  Though if you succeed
you'll be the first to do so with either a 16-bit target or a
non-gcc tool-chain, and you'll indeed be rolling in geek-points.

-- 
Grant Edwards                   grante             Yow!  People humiliating
                                  at               a salami!
                               visi.com            


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RE: [ECOS] Re: Preliminary questions on eCOS

[JS Stoezel]

Hello,

Thanks for your answer. We have been looking at FreeRTOS and uc/COSII
and where looking for alternate choices, because eCOS comes with added
features (FreeRTOS and uC provide limited services. I will have to take
a look at XMK.

Jean-Sebastien

> -----Original Message-----
> From: ecos-discuss-owner@ecos.sourceware.org 
> [mailto:ecos-discuss-owner@ecos.sourceware.org] On Behalf Of 
> Grant Edwards
> Sent: Tuesday, March 20, 2007 9:54 AM
> To: ecos-discuss@sources.redhat.com
> Subject: [ECOS] Re: Preliminary questions on eCOS
> 
> On 2007-03-20, JS Stoezel <js.stoezel@magellan.aero> wrote:
> 
> > I see there is no tool chain for this type of processor (this is 
> > stated here: http://ecos.sourceware.org/ecos/getstart.html).
> > However I can read: "Developers targeting one of the other 
> > architectures must build a toolchain themselves at present.
> > Full instructions for downloading source code and building 
> a toolchain 
> > are available.". Doesn't this mean I can port eCOS to the 
> tool chain I 
> > am using?
> 
> It means that if you want to target an architecture for which 
> there aren't a pre-built gcc/binutils tool-chains, you have 
> to download the gcc/binutils sources and build a tool-chain.
> 
> eCos uses a number of gcc C and C++ extensions as well as 
> some rather unique binutils features. In theory you could 
> port eCos to another tool-chain, but it's going to be tough. 
> People on the mailing list have talked about attempting to do 
> such a port, but I don't think anybody has reported success.
> 
> I'd probably look at other RTOSes (FreeRTOS, XMK, uC/OS-II) 
> before I'd start thinking about porting eCos to a 16-bit 
> processor using a non-gcc tool-chain.  Though if you succeed 
> you'll be the first to do so with either a 16-bit target or a 
> non-gcc tool-chain, and you'll indeed be rolling in geek-points.
> 
> -- 
> Grant Edwards                   grante             Yow!  
> People humiliating
>                                   at               a salami!
>                                visi.com            
> 
> 
> --
> Before posting, please read the FAQ: 
> http://ecos.sourceware.org/fom/ecos
> and search the list archive: 
> http://ecos.sourceware.org/ml/ecos-discuss
> 
> 

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[ECOS] Re: Preliminary questions on eCOS

[Grant Edwards]

On 2007-03-20, JS Stoezel <js.stoezel@magellan.aero> wrote:

> Thanks for your answer. We have been looking at FreeRTOS and
> uc/COSII and where looking for alternate choices, because eCOS
> comes with added features (FreeRTOS and uC provide limited
> services. I will have to take a look at XMK.

I'm not saying you couldn't get eCos to work, but it's going to
be a lot easier bringing up an RTOS that's toolchain-agnostic
and was designed to be run on 16-bit CPUs.

Purely out of curiousity, may I ask what services are
motivating the interest in eCos?

-- 
Grant Edwards                   grante             Yow!  You mean you don't
                                  at               want to watch WRESTLING
                               visi.com            from ATLANTA?


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RE: [ECOS] Re: Preliminary questions on eCOS

[Paul D. DeRocco]

> From: JS Stoezel
> 
> I see there is no tool chain for this type of processor (this 
> is stated
> here: http://ecos.sourceware.org/ecos/getstart.html). However I can
> read: "Developers targeting one of the other architectures 
> must build a toolchain themselves at present. Full 
> instructions for downloading source code and building a 
> toolchain are available.". Doesn't this mean I can port eCOS 
> to the tool chain I am using?

You could probably get the toolchain working in "tiny" mode, with a 64K
address space, but that's not enough room to spit. The problem is that the
16-bit x86 is a segmented architecture, and that makes for a very
non-standard code generator, not to mention the impact on the OS itself.

-- 

Ciao,               Paul D. DeRocco
Paul                mailto:pderocco@ix.netcom.com


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