[syslinux] Checking CRC (of bzImage) before loading

[Mau Z]

Thanks all,

It should be quick, so it will be implemented in C.

Maybe I should have stated that I am not an expert in syslinux (intelligent
but no expert).

I think that I understand the "custom COM32 module" option : I simply have
to change the code (and begin by looking into the files that were
suggested).

As for Peter's suggestion, I am not sure if I understood.
Is this an option which already exists ? How do I activate it ?

BTW, The binary file will probably be tar + gzip.
Does anybody know if there is a "gzip built in CRC test" ?
The easiest way would be to let gzip test the file..... It must be better
than what I can do.

Is there any code example ?  Or maybe another beginning point ?


Thanks
Mau



On Thu, Mar 20, 2014 at 12:45 PM, Ferenc Wagner <wferi at niif.hu> wrote:

> Mau Z <zmau1962 at gmail.com> writes:
>
> > I am wondering how to implement the following customer's requirement :
> > The system is a stand alone embedded system with no operator (with
> Linux).
> > There is one SSD for the system's usage (and that is where the system
> loads
> > from).
> >
> > The requirement is to have a duplication of the Linux Image, and that
> > syslinux should calculate CRC of "the first image" (say bzImage_1).
> > If the CRC is correct then load the image, if the CRC is not correct,
> than
> > syslinux should try "the other image" (say bzImage_2).
> > If even that is no good do nothing.
> >
> > Any suggestions as to how to implement the requirement ?
>
> You should be able to implement this logic via the embedded Lua
> interpreter.  I don't know whether the performance would be acceptable,
> though (at least without resorting to C coding).
> --
> Regards,
> Feri.
>