Commit 43fb2387 authored by Andi Kleen's avatar Andi Kleen Committed by Linus Torvalds
Browse files

i386: Add warning in Documentation that zero-page is not a stable ABI 



Some people writing boot loaders seem to falsely belief the 32bit zero page is a
stable interface for out of tree code like the real mode boot protocol. Add a comment
clarifying that is not true.

Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d3f7eae1

Documentation/i386/zero-page.txt

+10 −0
Original line number Diff line number Diff line 
---------------------------------------------------------------------------

!!!!!!!!!!!!!!!WARNING!!!!!!!!

The zero page is a kernel internal data structure, not a stable ABI.  It might change

without warning and the kernel has no way to detect old version of it.

If you're writing some external code like a boot loader you should only use

the stable versioned real mode boot protocol described in boot.txt. Otherwise the kernel

might break you at any time.

!!!!!!!!!!!!!WARNING!!!!!!!!!!!

----------------------------------------------------------------------------



Summary of boot_params layout (kernel point of view)

     ( collected by Hans Lermen and Martin Mares )

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