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

H. Peter Anvin
2006-10-06T18:55:27Z

Vivek Goyal wrote:
>>
> Hi Eric,
>
> I have added cld in the regenerated patch below.
>

No, the cld needs to be earlier. It turns out this isn't the first use
of string instructions.

I think I am going to add DF=0 as a documented entry condition; it
definitely seems all current Linux kernels require it.

> Also one more minor nit. stosb relies on being %es set properly. By the
> time control reaches loader_ok, i could not find %es being set explicitly
> hence I am assuming we are relying on bootloader to set it up for us.
>
> Maybe we can be little more paranoid and setup the %es before stosb. I
> have done this change too in the attached patch. Pleaese have a look.
> I know little about assembly code.

%es being set is part of the requirements list, although it *would* be
better to not rely on any segment registers being set at all (only rely
on %cs.)

-hpa