Re: [Etherboot-developers] booting non linux images

[Anuradha R. <anu...@gn...>]

On 18 May 2001, Eric W. Biederman wrote:

> Take a look at what I did.  At any rate the transformation from an ELF
> image to a tagged should be a simple 1-1 transformation.  If the
> tagged image needs a 16 bit entry point (I don't remember) you might
> need a bit of stub code but otherwise all is well.

What I like to do is to bypass the ELF part and use a 16 bit entry point.
Also, I _have_ converted the original memtest.bin binary to a tagged image
which goes direcly to setup.S code, everything in 16 bit real mode.

There is a very good reason change only bootsect.S and setup.S. These
files are not likely to change in the near future, unless they are
rewritten based on the corresponding files of a modern Linux source tree,
but this will rather _solve_ things out. So, a patch I create is likely to
apply cleanly on future versions of memtest86 too. Also, one of us likes
to try changes to the memory test part which I am _not_ interested in. So
we can keep our development seperate and neat.

However, bypassing of bootsect.S seem to be a problem (thanks Ken for
pointing this out), because some register values are not properly set,
notably ss:si. So I am now trying to do one of

1. add few lines to the beginning of setup.S to initialize necessary
   registers.

2. move the "jmp" line in bootsect.S which transfers control to setup.S
   to a place _before_ loading the rest from the floppy and use
   bootsect.S as entry point.

I have to do the testing somewhere else, so have to wait until my next
visit there to try these possibilities out. Will keep you updated about
the progress.

Thanks.

Regards and greetings,

Anuradha