Re: booting a ELF binary

[Richard Gooch <rgooch@atnf.CSIRO.AU>]

Rogier Wolff writes:
> Ton Biegstraaten wrote:
> > The program to be started should setup those low mem tables, then
> > loading the OS and start it, the priciple is easy,as usual.
> > I have a bootflop(SVR4 of course :-(), is it easy to change it into a
> > ramdisk?
> 
> Ton, 
> 
> Ik dacht dat er een manier was om van een bootflop een mkbni (of hoe
> dat ding ook heet) image te maken. De bootrom laat dan de boel achter
> in precies dezelfde staat als dat de BIOS met een boot-flop doet. Als
> de image op de flop dan echter direct naar de flop gaat om de rest op
> te halen ben je nat.....

The programme is called "mknbi-linux", BTW. If you have the
application binary you want to run (a SVR4 binary, right?), then you
can simply put that into a ramdisc as /sbin/init, and the kernel will
run it when it boots.
If it's a dynamically linked binary, you'll also need to put the
requisite libraries into /lib and possibly set up /etc/ld.so.cache.
If the application is only on your boot floppy, extracting it could be
fun :-)
Something you might like to consider is putting a slightly more
complete system onto your ramdisc (mine takes 3.5 MBytes
uncompressed), which allows you to log in at the console and rlogin
over the network.
The actual application is run by a script which loads the application
using tftp. If the application dies, a new version is grabbed using
tftp and run. This really cuts down the development cycle: you don't
even have to reboot to run a new version of your embedded
application.

				Groeten,

					Richard....