Re: [PATCH v2 2/2] m68k: Cleanup linker scripts using new linker script macros.

From: Tim Abbott
Date: Sun Sep 27 2009 - 14:00:41 EST


On Sun, 27 Sep 2009, Andreas Schwab wrote:

> Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> writes:
>
> > On Wed, Sep 16, 2009 at 18:44, Tim Abbott <tabbott@xxxxxxxxxxx> wrote:
> >> Signed-off-by: Tim Abbott <tabbott@xxxxxxxxxxx>
> >> Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> >> Cc: Roman Zippel <zippel@xxxxxxxxxxxxxx>
> >> Cc: linux-m68k@xxxxxxxxxxxxxxxxxxxx
> >> Cc: Sam Ravnborg <sam@xxxxxxxxxxxx>
> >
> > This patch must do something wrong, as it now fails to boot on ARAnyM:
> >
> > | CPU: Double bus fault detected !
> > | CPU: Halting
> >
> > Haven't investigated why yet, though...
>
> The problem is that _end no longer matches the end of the load segment.
> Previously, the .data.init_task section was the last allocated item in
> the linker script, now the last item is an align. This align does not
> affect the memsize of the segment. The startup code expects the boot
> info to be placed at _end, but the boot loader puts it at the end of the
> load segment, which is the best it can do.

Below is a new version of the second patch that attempts to address this
by putting the ALIGN inside a section, so that _end is at the end of the
load segment (I also did a bit more cleanup):

.init_end : {
/* This ALIGN be in a section so that _end is at the end of the
load segment. */
. = ALIGN(PAGE_SIZE);
__init_end = .;
}

_end = .;

-Tim Abbott

m68k: Cleanup linker scripts using new linker script macros.

Signed-off-by: Tim Abbott <tabbott@xxxxxxxxxxx>
Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Cc: Roman Zippel <zippel@xxxxxxxxxxxxxx>
Cc: linux-m68k@xxxxxxxxxxxxxxxxxxxx
Cc: Sam Ravnborg <sam@xxxxxxxxxxxx>
---
arch/m68k/kernel/vmlinux-std.lds | 61 ++++++++-----------------------------
arch/m68k/kernel/vmlinux-sun3.lds | 54 ++++----------------------------
2 files changed, 20 insertions(+), 95 deletions(-)

diff --git a/arch/m68k/kernel/vmlinux-std.lds b/arch/m68k/kernel/vmlinux-std.lds
index 47eac19..878be5f 100644
--- a/arch/m68k/kernel/vmlinux-std.lds
+++ b/arch/m68k/kernel/vmlinux-std.lds
@@ -2,6 +2,7 @@

#include <asm-generic/vmlinux.lds.h>
#include <asm/page.h>
+#include <asm/thread_info.h>

OUTPUT_FORMAT("elf32-m68k", "elf32-m68k", "elf32-m68k")
OUTPUT_ARCH(m68k)
@@ -22,73 +23,37 @@ SECTIONS

_etext = .; /* End of text section */

- . = ALIGN(16); /* Exception table */
- __start___ex_table = .;
- __ex_table : { *(__ex_table) }
- __stop___ex_table = .;
+ EXCEPTION_TABLE(16)

RODATA

- .data : { /* Data */
- DATA_DATA
- CONSTRUCTORS
- }
+ RW_DATA_SECTION(16, PAGE_SIZE, THREAD_SIZE)

- . = ALIGN(16);
- .data.cacheline_aligned : { *(.data.cacheline_aligned) }
-
- .bss : { *(.bss) } /* BSS */
+ BSS_SECTION(0, 0, 0)

_edata = .; /* End of data section */

/* will be freed after init */
. = ALIGN(PAGE_SIZE); /* Init code and data */
__init_begin = .;
- .init.text : {
- _sinittext = .;
- INIT_TEXT
- _einittext = .;
- } :data
- .init.data : { INIT_DATA }
- . = ALIGN(16);
- __setup_start = .;
- .init.setup : { *(.init.setup) }
- __setup_end = .;
- __initcall_start = .;
- .initcall.init : {
- INITCALLS
- }
- __initcall_end = .;
- __con_initcall_start = .;
- .con_initcall.init : { *(.con_initcall.init) }
- __con_initcall_end = .;
+ INIT_TEXT_SECTION(PAGE_SIZE) :data
+ INIT_DATA_SECTION(16)
.m68k_fixup : {
__start_fixup = .;
*(.m68k_fixup)
__stop_fixup = .;
}
- SECURITY_INIT
-#ifdef CONFIG_BLK_DEV_INITRD
- . = ALIGN(8192);
- __initramfs_start = .;
- .init.ramfs : { *(.init.ramfs) }
- __initramfs_end = .;
-#endif
NOTES
- . = ALIGN(8192);
- __init_end = .;
-
- .data.init_task : { *(.data.init_task) } /* The initial task and kernel stack */
+ .init_end : {
+ /* This ALIGN be in a section so that _end is at the end of the
+ load segment. */
+ . = ALIGN(PAGE_SIZE);
+ __init_end = .;
+ }

_end = . ;

- /* Stabs debugging sections. */
- .stab 0 : { *(.stab) }
- .stabstr 0 : { *(.stabstr) }
- .stab.excl 0 : { *(.stab.excl) }
- .stab.exclstr 0 : { *(.stab.exclstr) }
- .stab.index 0 : { *(.stab.index) }
- .stab.indexstr 0 : { *(.stab.indexstr) }
+ STABS_DEBUG
.comment 0 : { *(.comment) }

/* Sections to be discarded */
diff --git a/arch/m68k/kernel/vmlinux-sun3.lds b/arch/m68k/kernel/vmlinux-sun3.lds
index 03efaf0..1ad6b7a 100644
--- a/arch/m68k/kernel/vmlinux-sun3.lds
+++ b/arch/m68k/kernel/vmlinux-sun3.lds
@@ -2,6 +2,7 @@

#include <asm-generic/vmlinux.lds.h>
#include <asm/page.h>
+#include <asm/thread_info.h>

OUTPUT_FORMAT("elf32-m68k", "elf32-m68k", "elf32-m68k")
OUTPUT_ARCH(m68k)
@@ -23,14 +24,8 @@ SECTIONS

_etext = .; /* End of text section */

- .data : { /* Data */
- DATA_DATA
- CONSTRUCTORS
- . = ALIGN(16); /* Exception table */
- __start___ex_table = .;
- *(__ex_table)
- __stop___ex_table = .;
- } :data
+ EXCEPTION_TABLE(16) :data
+ RW_DATA_SECTION(16, PAGE_SIZE, THREAD_SIZE) :data
/* End of data goes *here* so that freeing init code works properly. */
_edata = .;
NOTES
@@ -38,56 +33,21 @@ SECTIONS
/* will be freed after init */
. = ALIGN(PAGE_SIZE); /* Init code and data */
__init_begin = .;
- .init.text : {
- _sinittext = .;
- INIT_TEXT
- _einittext = .;
- }
- .init.data : { INIT_DATA }
- . = ALIGN(16);
- __setup_start = .;
- .init.setup : { *(.init.setup) }
- __setup_end = .;
- __initcall_start = .;
- .initcall.init : {
- INITCALLS
- }
- __initcall_end = .;
- __con_initcall_start = .;
- .con_initcall.init : { *(.con_initcall.init) }
- __con_initcall_end = .;
+ INIT_TEXT_SECTION(PAGE_SIZE)
+ INIT_DATA_SECTION(16)
.m68k_fixup : {
__start_fixup = .;
*(.m68k_fixup)
__stop_fixup = .;
}
- SECURITY_INIT
-#ifdef CONFIG_BLK_DEV_INITRD
- . = ALIGN(PAGE_SIZE);
- __initramfs_start = .;
- .init.ramfs : { *(.init.ramfs) }
- __initramfs_end = .;
-#endif
. = ALIGN(PAGE_SIZE);
__init_end = .;
- .data.init.task : { *(.data.init_task) }
-

- .bss : { *(.bss) } /* BSS */
+ BSS_SECTION(0, 0, 0)

_end = . ;

- .crap : {
- /* Stabs debugging sections. */
- *(.stab)
- *(.stabstr)
- *(.stab.excl)
- *(.stab.exclstr)
- *(.stab.index)
- *(.stab.indexstr)
- *(.comment)
- *(.note)
- }
+ STABS_DEBUG

/* Sections to be discarded */
DISCARDS
--
1.6.3.3

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