On Tue, 18 Jul 2006, Martin Schwidefsky wrote:
> From: Heiko Carstens <[email protected]>
>
> [S390] .align 4096 statements in head.S
>
> SLES9 binutils don't like .align 4096 statements in head.S. Work around this
> by using .org statements.
>
> Signed-off-by: Heiko Carstens <[email protected]>
> Signed-off-by: Martin Schwidefsky <[email protected]>
> ---
>
> arch/s390/kernel/head31.S | 4 ++--
> arch/s390/kernel/head64.S | 4 ++--
> 2 files changed, 4 insertions(+), 4 deletions(-)
>
> diff -urpN linux-2.6/arch/s390/kernel/head31.S linux-2.6-patched/arch/s390/kernel/head31.S
> --- linux-2.6/arch/s390/kernel/head31.S 2006-07-18 13:40:23.000000000 +0200
> +++ linux-2.6-patched/arch/s390/kernel/head31.S 2006-07-18 13:40:46.000000000 +0200
> @@ -273,7 +273,7 @@ startup_continue:
> .Lbss_end: .long _end
> .Lparmaddr: .long PARMAREA
> .Lsccbaddr: .long .Lsccb
> - .align 4096
> + .org 0x12000
> .Lsccb:
> .hword 0x1000 # length, one page
> .byte 0x00,0x00,0x00
> @@ -290,7 +290,7 @@ startup_continue:
> .Lscpincr2:
> .quad 0x00
> .fill 3984,1,0
> - .align 4096
> + .org 0x13000
>
> #ifdef CONFIG_SHARED_KERNEL
> .org 0x100000
> diff -urpN linux-2.6/arch/s390/kernel/head64.S linux-2.6-patched/arch/s390/kernel/head64.S
> --- linux-2.6/arch/s390/kernel/head64.S 2006-07-18 13:40:23.000000000 +0200
> +++ linux-2.6-patched/arch/s390/kernel/head64.S 2006-07-18 13:40:46.000000000 +0200
> @@ -268,7 +268,7 @@ startup_continue:
> .Lparmaddr:
> .quad PARMAREA
>
> - .align 4096
> + .org 0x12000
> .Lsccb:
> .hword 0x1000 # length, one page
> .byte 0x00,0x00,0x00
> @@ -285,7 +285,7 @@ startup_continue:
> .Lscpincr2:
> .quad 0x00
> .fill 3984,1,0
> - .align 4096
> + .org 0x13000
>
> #ifdef CONFIG_SHARED_KERNEL
> .org 0x100000
> -
Hardcoading like that can cause hard to find errors. It looks like
you wrote something in 'C' and tried to use its assembly code. You
should know that you don't need ".fill" if you have correctly allocated
data.
The following will align objects on a 0x1000 boundary:
.section .data
foo: .word 0
.org (. + 0x1000) & -0x1000
bar: .word 0
.org (. + 0x1000) & -0x1000
xxx: .word 0
.org (. + 0x1000) & -0x1000
yyy: .word 0
.end
The 'gas' assembler is very powerful and even allows macros:
.macro ALIGN val
.org (. + \val) & -\val
.endm
.section .data
foo: .word 0
ALIGN 0x1000
bar: .word 0
ALIGN 0x1000
xxx: .word 0
ALIGN 0x1000
yyy: .word 0
ALIGN 0x1000
qqq: .word 0
.end
This generates:
Disassembly of section .data:
00000000 <foo>:
...
00001000 <bar>:
...
00002000 <xxx>:
...
00003000 <yyy>:
...
00004000 <qqq>:
...
Note the alignment.
You might want to use this kind of construction because it will
eliminate alignment errors. If you add something that's out-of-range
'gas' will generate an error (like attempt of a negative origin).
Cheers,
Dick Johnson
Penguin : Linux version 2.6.16.24 on an i686 machine (5592.63 BogoMips).
New book: http://www.AbominableFirebug.com/
_
****************************************************************
The information transmitted in this message is confidential and may be privileged. Any review, retransmission, dissemination, or other use of this information by persons or entities other than the intended recipient is prohibited. If you are not the intended recipient, please notify Analogic Corporation immediately - by replying to this message or by sending an email to [email protected] - and destroy all copies of this information, including any attachments, without reading or disclosing them.
Thank you.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
