Re: [PATCH 12/12] i386 boot: Add an ELF header to bzImage

[H. Peter Anvin]

Eric W. Biederman wrote:
> > The entrypoint is going to be a major headache, since the standard kernel is
> > entered in real mode, whereas an ELF file will typically be entered in protected
> > mode, quite possibly using the C calling convention to pass the command line as
> > (argc, argv).  God only knows how they're going to deal with an initrd.
> >
> > It may very well be that the ELF magic number has to be obfuscated.
>
> The entry point that is exported is the kernels protected mode entry point
> that is used after the real mode code has been run.  This is to allow
> bootloaders like kexec where running the real-mode code is insane or
> impossible to be used.  
>
> The calling conventions though are not changed, this is just formalizing
> something that various groups have been doing for years.  Since it is
> all in the bzImage we still only have a single file format to support,
> so any bootloader that can load a standard bzImage and run the kernels
> real mode code should still do it that way but.  If you can't the
> rest of the information is available.

Well, it doesn't help if what you end up with for some bootloader is a 
nonfunctioning kernel.

	-hpa
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