Application Exception Handling

[kalyani]

Hi all,
I am working on ECOS operating system. In this i want to implement the exception handlers to my application. i have gone through some documents provided in the site but i am unable to find the procedure to implement the exception handlers. Can you tell me where can i get the information regarding this, any recent documents are there? or can anyone suggest me some idea to implement the Application Exception handling.

Regards,
Kalyani

[Nick Garnett]

kalyani <Kalyani.Korubilli@...> writes:

> Hi all,
> I am working on ECOS operating system. In this i want to implement the
> exception handlers to my application. i have gone through some documents
> provided in the site but i am unable to find the procedure to implement the
> exception handlers. Can you tell me where can i get the information
> regarding this, any recent documents are there? or can anyone suggest me
> some idea to implement the Application Exception handling.

If you want to handle hardware exceptions then you can either plug
your own routines into the VSR table or enable the kernel exception
delivery mechanism. Documentation for the former can be found here:

http://ecos.sourceware.org/docs-latest/ref/hal-interrupt-handling.html

Documentation for the latter can be found here:

http://ecos.sourceware.org/docs-latest/ref/kernel-exceptions.html

--
Nick Garnett                                 eCos Kernel Architect
http://www.ecoscentric.com            The eCos and RedBoot experts

[kalyani]

Hi, thanks for the reply. Actually i am new to this concept, i have gone through the links which you have sent. How to write our own exception handlers into VSR is what i want to know. I want to implement this at Application level. Kernel exception is the default configuration as i understood from the document. It is given that VSRshould be written in assembly language for Application exception handler. Can you please clarify all my doubts and please can you provide me any example codes for this exception handlers if any which have already been  implemented.

Regards,
Kalyani

Nick Garnett wrote:

kalyani <[e-mail]> writes:

> Hi all,
> I am working on ECOS operating system. In this i want to implement the
> exception handlers to my application. i have gone through some documents
> provided in the site but i am unable to find the procedure to implement the
> exception handlers. Can you tell me where can i get the information
> regarding this, any recent documents are there? or can anyone suggest me
> some idea to implement the Application Exception handling.

If you want to handle hardware exceptions then you can either plug
your own routines into the VSR table or enable the kernel exception
delivery mechanism. Documentation for the former can be found here:

http://ecos.sourceware.org/docs-latest/ref/hal-interrupt-handling.html

Documentation for the latter can be found here:

http://ecos.sourceware.org/docs-latest/ref/kernel-exceptions.html

--
Nick Garnett                                 eCos Kernel Architect
http://www.ecoscentric.com            The eCos and RedBoot experts

[Nick Garnett]

kalyani <Kalyani.Korubilli@...> writes:

> Hi, thanks for the reply. Actually i am new to this concept, i have gone
> through the links which you have sent. How to write our own exception
> handlers into VSR is what i want to know. I want to implement this at
> Application level. Kernel exception is the default configuration as i
> understood from the document. It is given that VSRshould be written in
> assembly language for Application exception handler. Can you please clarify
> all my doubts and please can you provide me any example codes for this
> exception handlers if any which have already been  implemented.

VSRs are entered after minimal processing and with the state as close
to the CPU exception entry state as possible. If there has been any
decoding of the exception source then some registers may have been
saved somewhere architecture specific and will now contain some other
data -- usually some representation of the exception number or VSR
table index.

Plugging the VSRs is not done very often, and there are no
examples. You don't say what architecture you are working on, so any
example may not be appropriate. Mainly you need to know about how the
CPU delivers exceptions.

The best thing to do is to look at how the default exception VSR
handler works in vectors.S and duplicate it as far as is necessary for
your purposes.


--
Nick Garnett                                 eCos Kernel Architect
http://www.ecoscentric.com            The eCos and RedBoot experts