PATCH] x86_64: fix comments in vmlinux_64.lds

PATCH] x86_64: fix comments in vmlinux_64.lds

[Yinghai Lu]

[PATCH] x86_64: fix comments in vmlinux_64.lds

for bzImage, the vmlinux_64.lds still have s32 bit code, and startup_32 should
bt 0. fix the comment

Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>

diff --git a/arch/x86/boot/compressed/vmlinux_64.lds b/arch/x86/boot/compressed/vmlinux_64.lds
index f6e5b44..7e5c720 100644
--- a/arch/x86/boot/compressed/vmlinux_64.lds
+++ b/arch/x86/boot/compressed/vmlinux_64.lds
@@ -3,7 +3,7 @@ OUTPUT_ARCH(i386:x86-64)
 ENTRY(startup_64)
 SECTIONS
 {
-	/* Be careful parts of head_64.S assume startup_64 is at
+	/* Be careful parts of head_64.S assume startup_32 is at
 	 * address 0.
 	 */
 	. = 0;

Re: PATCH] x86_64: fix comments in vmlinux_64.lds

[Ingo Molnar]

* Yinghai Lu <Yinghai.Lu@Sun.COM> wrote:

>  ENTRY(startup_64)
>  SECTIONS
>  {
> -	/* Be careful parts of head_64.S assume startup_64 is at
> +	/* Be careful parts of head_64.S assume startup_32 is at
>  	 * address 0.
>  	 */
>  	. = 0;

but this linker script rule is about startup_64, not about startup_32.

startup_32 does exist on 64-bit too (and is 32-bit code), but it's 
linked to a different address that is not 0:

 ffffffff806c23c0 r startup_32

startup_64 is at offset 0:

 ffffffff80200000 T startup_64

So your patch looks wrong to me.

	Ingo

Re: PATCH] x86_64: fix comments in vmlinux_64.lds

[Yinghai Lu]

On Thursday 31 January 2008 04:35:03 am Ingo Molnar wrote:
> 
> * Yinghai Lu <Yinghai.Lu@Sun.COM> wrote:
> 
> >  ENTRY(startup_64)
> >  SECTIONS
> >  {
> > -	/* Be careful parts of head_64.S assume startup_64 is at
> > +	/* Be careful parts of head_64.S assume startup_32 is at
> >  	 * address 0.
> >  	 */
> >  	. = 0;
> 
> but this linker script rule is about startup_64, not about startup_32.
> 
> startup_32 does exist on 64-bit too (and is 32-bit code), but it's 
> linked to a different address that is not 0:
> 
>  ffffffff806c23c0 r startup_32
> 
> startup_64 is at offset 0:
> 
>  ffffffff80200000 T startup_64
> 
> So your patch looks wrong to me.

there are several startup_32 in 64 bit
1. one is for bzImage, it is arch/x86/boot/compressed/head_64.S, and it said startup_64 will at 0x200. that what i mean
2. one is vmlinux in linux-2.6/ , it is in arch/x86/kernel/trampoline_64.S  it is for AP trampoline and wake up. that is what you mean

actually there was another one in arch/x86_64/kernel/head_64.S, and it was removed when Eric made linux-2.6/vmlinux to be 64bit elf. 

So that patch is needed.

YH