From: R Vamshi Krishna <vamshi@cse.iitb.ac.in>
To: John Carter <john.carter@tait.co.nz>
Cc: ecos-discuss@sourceware.org
Subject: Re: [ECOS] Hard-Realtime behaviour
Date: Sun, 18 Jun 2006 23:46:00 -0000 [thread overview]
Message-ID: <Pine.LNX.4.61.0606190507480.4377@mars.cse.iitb.ac.in> (raw)
In-Reply-To: <Pine.LNX.4.64.0606191117470.3234@parore>
Thank you for the reply. But the fact remains that we would like to have a
"Hard" real-time OS irrespective of the processor/speed and ram/rom.
Any help regarding hardening of eCos would be welcome.
On Mon, 19 Jun 2006, John Carter wrote:
> On Mon, 19 Jun 2006, R Vamshi Krishna wrote:
>
>> Now this hard real-time OS would be for use in Safety-Critical Systems. We
>> would port the kernel to MISRA-C later stage but currently we are stuck-up
>> at "hardening" of eCos.
>
> Since currently most of the kernel seems to be C++, that wouldn't be
> "port", that would be "rewrite". ie. If MISRA-C for the kernel is a
> fixed requirement, you have lost right there.
>
My mistake. I indeed did mean re-write.
>> This guarantee I understand cannot be given by an RTOS alone. It is the
>> combined guarantee by the application + RTOS. i.e. everything depends on
>> the way the application was developed using the features of an RTOS.
>
> Comment 1: Ecos has met all hard deadline requirements on our app...
> Getting our code to behave has been way more problematical than Ecos.
>
> Comment 2: Given a choice of a "harder RTOS" than ecos, "misra-c"
> kernel, or a faster / smarter CPU with loads of Flash/RAM, I will take
> the faster smarter CPU.
>
> Headroom and flexibility are more important than "guarantees".
> Guarantees can be broken, but headroom lets you cope with any broken
> guarantees and a lot more besides.
>
> Comment 3: Most "hard to meet hard deadlines" I have seen have been the
> result of
> hardware designers saying "lets skimp a bit and fix it in the software".
>
> So if you have a really hard hard to meet RT deadline, walk over to your
> hardware designers and talk to them about life, the universe, safety and
> trade offs.
>
>
>
>
> John Carter Phone : (64)(3) 358 6639
> Tait Electronics Fax : (64)(3) 359 4632
> PO Box 1645 Christchurch Email : john.carter@tait.co.nz
> New Zealand
>
> Carter's Clarification of Murphy's Law.
>
> "Things only ever go right so that they may go more spectacularly wrong
> later."
>
> From this principle, all of life and physics may be deduced.
>
--
Regards,
Vamshi
-------------------------------------------------
R.Vamshi Krishna,
M.Tech. CSE (II year),
IIT Bombay
Room no. 320, A-wing, Hostel-12
Mobile : +919869781633
-------------------------------------------------
Yesterday is a past, tomorrow is a future , today is a gift that's why it's called 'present'
--
Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss
next prev parent reply other threads:[~2006-06-18 23:46 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-05-29 16:09 R Vamshi Krishna
2006-05-29 16:26 ` Fabian Scheler
2006-05-29 21:16 ` Wolfgang Köbler
2006-05-30 5:13 ` R Vamshi Krishna
2006-05-30 7:53 ` Andrew Lunn
2006-05-30 8:09 ` Fabian Scheler
2006-05-30 8:16 ` Andrew Lunn
2006-05-30 9:25 ` R Vamshi Krishna
2006-05-30 11:12 ` Andrew Lunn
[not found] ` <Pine.LNX.4.61.0 606031953120.6382@mars.cse.iitb.ac.in>
[not found] ` <Pine.LNX.4.61.0 606031953120.6382@mars.cse.iitb.ac.in>
[not found] ` <"Pine.LNX.4.61 .0 606031953120.6382"@mars.cse.iitb.ac.in>
[not found] ` <Pine.LNX.4.61.0606040253350.26447@m ars.cse.iitb.ac.in>
2006-06-03 16:26 ` R Vamshi Krishna
2006-06-03 20:13 ` Roy E Richardson
2006-06-03 21:31 ` R Vamshi Krishna
[not found] ` <003401c6885d $23027ee0$070fe644@EngAtPlayWS>
[not found] ` <003401c6885d $23027ee0$070fe644@EngAtPlayWS>
[not found] ` <003401c6885d$23027ee0$070fe644@EngAtPlayWS>
2006-06-18 22:21 ` R Vamshi Krishna
2006-06-18 23:31 ` John Carter
2006-06-18 23:46 ` R Vamshi Krishna [this message]
2006-06-19 0:27 ` John Carter
2006-05-30 11:15 ` Andrew Lunn
2006-05-30 14:44 ` Enno Luebbers
2006-05-30 9:34 ` Nils Labugt
2006-05-30 10:37 ` Fabian Scheler
2006-05-30 11:21 ` Luis Friedrich
2006-05-30 11:47 ` Fabian Scheler
2006-05-30 12:48 ` R Vamshi Krishna
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=Pine.LNX.4.61.0606190507480.4377@mars.cse.iitb.ac.in \
--to=vamshi@cse.iitb.ac.in \
--cc=ecos-discuss@sourceware.org \
--cc=john.carter@tait.co.nz \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).