Patch to make the head.S-must-be-first-in-vmlinux order explicit From: Arjan van de Ven This patch puts the code from head.S in a special .bootstrap.text section. I'm working on a patch to reorder the functions in the kernel (I'll post that later), but for x86-64 at least the kernel bootstrap requires that the head.S functions are on the very first page/pages of the kernel text. This is understandable since the bootstrap is complex enough already and not a problem at all, it just means they aren't allowed to be reordered. This patch puts these special functions into a separate section to document this, and to guarantee this in the light of possibly reordering the rest later. (So this patch doesn't fix a bug per se, but makes things more robust by making the order of these functions explicit) Signed-off-by: Arjan van de Ven Signed-off-by: Andi Kleen --- arch/x86_64/kernel/head.S | 1 + arch/x86_64/kernel/vmlinux.lds.S | 1 + 2 files changed, 2 insertions(+) Index: linux/arch/x86_64/kernel/head.S =================================================================== --- linux.orig/arch/x86_64/kernel/head.S +++ linux/arch/x86_64/kernel/head.S @@ -26,6 +26,7 @@ */ .text + .section .bootstrap.text .code32 .globl startup_32 /* %bx: 1 if coming from smp trampoline on secondary cpu */ Index: linux/arch/x86_64/kernel/vmlinux.lds.S =================================================================== --- linux.orig/arch/x86_64/kernel/vmlinux.lds.S +++ linux/arch/x86_64/kernel/vmlinux.lds.S @@ -20,6 +20,7 @@ SECTIONS phys_startup_64 = startup_64 - LOAD_OFFSET; _text = .; /* Text and read-only data */ .text : AT(ADDR(.text) - LOAD_OFFSET) { + *(.bootstrap.text) *(.text) SCHED_TEXT LOCK_TEXT