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Re: ROMRAM startup in arm arch
- From: "Gary D. Thomas" <gary dot thomas at mind dot be>
- To: Fabrice Gautier <Fabrice_Gautier at sdesigns dot com>
- Cc: "Ecos-List (E-mail)" <ecos-discuss at sources dot redhat dot com>
- Date: 30 Jan 2003 18:51:02 -0700
- Subject: Re: [ECOS] ROMRAM startup in arm arch
- References: <9F77D654ED40B74CA79E5A60B97A087B0423F5@sd-exchange.sdesigns.com>
On Thu, 2003-01-30 at 18:17, Fabrice Gautier wrote:
> Hi,
>
> It seems to me than when ROMRAM startup is choosen, the data section is
> copied twice. (I've looked into integrator and ebdxxx platforms). The first
> time in the platform specific code, along with the text section, and the
> second time is in vector.S. This second time is need to copy the data
> section in case of ROM startup.
>
> Is there really a need to copy twice here ?
I think you're right although the copy of the DATA segment
is a no-op (bytes are copied over themselves). I'm sure
that the reason it was done this way was for simplicity.
Also, if there ever was a case where the memory layout
for a ROMRAM startup program did not have the DATA segment
immediately follow the TEXT, this code would have to be
executed. Doing it always relieves the code from knowing
if this is the case.
--
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| Mind: Embedded Linux and eCos Development |
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| Gary Thomas email: gary.thomas@mind.be |
| Mind ( http://mind.be ) tel: +1 (970) 229-1963 |
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