* [PATCH] [POWERPC] Update linker script to properly set physical addresses
@ 2008-04-03 6:29 Kumar Gala
2008-04-07 6:01 ` Paul Mackerras
0 siblings, 1 reply; 3+ messages in thread
From: Kumar Gala @ 2008-04-03 6:29 UTC (permalink / raw)
To: Paul Mackerras; +Cc: linuxppc-dev
We can set LOAD_OFFSET and use the AT attribute on sections and the
linker will properly set the physical address of the LOAD program
header for us.
This allows us to know how the PHYSICAL_START the user configured a
kernel with by just looking at the resulting vmlinux ELF.
This is pretty much stolen from how x86 does things in their linker
scripts.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
---
Paul,
This patch is top of my existing series of mm init cleanup/rework.
- k
arch/powerpc/kernel/vmlinux.lds.S | 47 ++++++++++++++++++-------------------
include/asm-powerpc/page.h | 1 +
2 files changed, 24 insertions(+), 24 deletions(-)
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index b5a76bc..0c3000b 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -31,7 +31,7 @@ SECTIONS
*/
/* Text and gots */
- .text : {
+ .text : AT(ADDR(.text) - LOAD_OFFSET) {
ALIGN_FUNCTION();
*(.text.head)
_text = .;
@@ -56,7 +56,7 @@ SECTIONS
RODATA
/* Exception & bug tables */
- __ex_table : {
+ __ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {
__start___ex_table = .;
*(__ex_table)
__stop___ex_table = .;
@@ -72,7 +72,7 @@ SECTIONS
. = ALIGN(PAGE_SIZE);
__init_begin = .;
- .init.text : {
+ .init.text : AT(ADDR(.init.text) - LOAD_OFFSET) {
_sinittext = .;
INIT_TEXT
_einittext = .;
@@ -81,11 +81,11 @@ SECTIONS
/* .exit.text is discarded at runtime, not link time,
* to deal with references from __bug_table
*/
- .exit.text : {
+ .exit.text : AT(ADDR(.exit.text) - LOAD_OFFSET) {
EXIT_TEXT
}
- .init.data : {
+ .init.data : AT(ADDR(.init.data) - LOAD_OFFSET) {
INIT_DATA
__vtop_table_begin = .;
*(.vtop_fixup);
@@ -101,19 +101,19 @@ SECTIONS
}
. = ALIGN(16);
- .init.setup : {
+ .init.setup : AT(ADDR(.init.setup) - LOAD_OFFSET) {
__setup_start = .;
*(.init.setup)
__setup_end = .;
}
- .initcall.init : {
+ .initcall.init : AT(ADDR(.initcall.init) - LOAD_OFFSET) {
__initcall_start = .;
INITCALLS
__initcall_end = .;
}
- .con_initcall.init : {
+ .con_initcall.init : AT(ADDR(.con_initcall.init) - LOAD_OFFSET) {
__con_initcall_start = .;
*(.con_initcall.init)
__con_initcall_end = .;
@@ -122,14 +122,14 @@ SECTIONS
SECURITY_INIT
. = ALIGN(8);
- __ftr_fixup : {
+ __ftr_fixup : AT(ADDR(__ftr_fixup) - LOAD_OFFSET) {
__start___ftr_fixup = .;
*(__ftr_fixup)
__stop___ftr_fixup = .;
}
#ifdef CONFIG_PPC64
. = ALIGN(8);
- __fw_ftr_fixup : {
+ __fw_ftr_fixup : AT(ADDR(__fw_ftr_fixup) - LOAD_OFFSET) {
__start___fw_ftr_fixup = .;
*(__fw_ftr_fixup)
__stop___fw_ftr_fixup = .;
@@ -137,14 +137,14 @@ SECTIONS
#endif
#ifdef CONFIG_BLK_DEV_INITRD
. = ALIGN(PAGE_SIZE);
- .init.ramfs : {
+ .init.ramfs : AT(ADDR(.init.ramfs) - LOAD_OFFSET) {
__initramfs_start = .;
*(.init.ramfs)
__initramfs_end = .;
}
#endif
. = ALIGN(PAGE_SIZE);
- .data.percpu : {
+ .data.percpu : AT(ADDR(.data.percpu) - LOAD_OFFSET) {
__per_cpu_start = .;
*(.data.percpu)
*(.data.percpu.shared_aligned)
@@ -152,7 +152,7 @@ SECTIONS
}
. = ALIGN(8);
- .machine.desc : {
+ .machine.desc : AT(ADDR(.machine.desc) - LOAD_OFFSET) {
__machine_desc_start = . ;
*(.machine.desc)
__machine_desc_end = . ;
@@ -170,25 +170,24 @@ SECTIONS
_sdata = .;
#ifdef CONFIG_PPC32
- .data :
- {
+ .data : AT(ADDR(.data) - LOAD_OFFSET) {
DATA_DATA
*(.sdata)
*(.got.plt) *(.got)
}
#else
- .data : {
+ .data : AT(ADDR(.data) - LOAD_OFFSET) {
DATA_DATA
*(.data.rel*)
*(.toc1)
*(.branch_lt)
}
- .opd : {
+ .opd : AT(ADDR(.opd) - LOAD_OFFSET) {
*(.opd)
}
- .got : {
+ .got : AT(ADDR(.got) - LOAD_OFFSET) {
__toc_start = .;
*(.got)
*(.toc)
@@ -205,26 +204,26 @@ SECTIONS
#else
. = ALIGN(16384);
#endif
- .data.init_task : {
+ .data.init_task : AT(ADDR(.data.init_task) - LOAD_OFFSET) {
*(.data.init_task)
}
. = ALIGN(PAGE_SIZE);
- .data.page_aligned : {
+ .data.page_aligned : AT(ADDR(.data.page_aligned) - LOAD_OFFSET) {
*(.data.page_aligned)
}
- .data.cacheline_aligned : {
+ .data.cacheline_aligned : AT(ADDR(.data.cacheline_aligned) - LOAD_OFFSET) {
*(.data.cacheline_aligned)
}
. = ALIGN(L1_CACHE_BYTES);
- .data.read_mostly : {
+ .data.read_mostly : AT(ADDR(.data.read_mostly) - LOAD_OFFSET) {
*(.data.read_mostly)
}
. = ALIGN(PAGE_SIZE);
- __data_nosave : {
+ .data_nosave : AT(ADDR(.data_nosave) - LOAD_OFFSET) {
__nosave_begin = .;
*(.data.nosave)
. = ALIGN(PAGE_SIZE);
@@ -235,7 +234,7 @@ SECTIONS
* And finally the bss
*/
- .bss : {
+ .bss : AT(ADDR(.bss) - LOAD_OFFSET) {
__bss_start = .;
*(.sbss) *(.scommon)
*(.dynbss)
diff --git a/include/asm-powerpc/page.h b/include/asm-powerpc/page.h
index adf0591..cffdf0e 100644
--- a/include/asm-powerpc/page.h
+++ b/include/asm-powerpc/page.h
@@ -69,6 +69,7 @@
#define KERNELBASE ASM_CONST(CONFIG_KERNEL_START)
#define PAGE_OFFSET ASM_CONST(CONFIG_PAGE_OFFSET)
+#define LOAD_OFFSET ASM_CONST((CONFIG_KERNEL_START-CONFIG_PHYSICAL_START))
#if defined(CONFIG_RELOCATABLE) && defined(CONFIG_FLATMEM)
#ifndef __ASSEMBLY__
--
1.5.4.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] [POWERPC] Update linker script to properly set physical addresses
2008-04-03 6:29 [PATCH] [POWERPC] Update linker script to properly set physical addresses Kumar Gala
@ 2008-04-07 6:01 ` Paul Mackerras
2008-04-07 13:00 ` Kumar Gala
0 siblings, 1 reply; 3+ messages in thread
From: Paul Mackerras @ 2008-04-07 6:01 UTC (permalink / raw)
To: Kumar Gala; +Cc: linuxppc-dev
Kumar Gala writes:
> We can set LOAD_OFFSET and use the AT attribute on sections and the
> linker will properly set the physical address of the LOAD program
> header for us.
Nice...
> #define KERNELBASE ASM_CONST(CONFIG_KERNEL_START)
> #define PAGE_OFFSET ASM_CONST(CONFIG_PAGE_OFFSET)
> +#define LOAD_OFFSET ASM_CONST((CONFIG_KERNEL_START-CONFIG_PHYSICAL_START))
I think this should be CONFIG_PAGE_OFFSET - CONFIG_PHYSICAL_START
though.
Paul.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] [POWERPC] Update linker script to properly set physical addresses
2008-04-07 6:01 ` Paul Mackerras
@ 2008-04-07 13:00 ` Kumar Gala
0 siblings, 0 replies; 3+ messages in thread
From: Kumar Gala @ 2008-04-07 13:00 UTC (permalink / raw)
To: Paul Mackerras; +Cc: linuxppc-dev
On Apr 7, 2008, at 1:01 AM, Paul Mackerras wrote:
> Kumar Gala writes:
>
>> We can set LOAD_OFFSET and use the AT attribute on sections and the
>> linker will properly set the physical address of the LOAD program
>> header for us.
>
> Nice...
>
>> #define KERNELBASE ASM_CONST(CONFIG_KERNEL_START)
>> #define PAGE_OFFSET ASM_CONST(CONFIG_PAGE_OFFSET)
>> +#define LOAD_OFFSET ASM_CONST((CONFIG_KERNEL_START-
>> CONFIG_PHYSICAL_START))
>
> I think this should be CONFIG_PAGE_OFFSET - CONFIG_PHYSICAL_START
> though.
Disagree (assuming I'm thinking straight first thing in the morning).
PAGE_OFFSET is virt address of the beginning of memory, where
KERNEL_START is virt address of start of kernel text.
PHYSICAL_START is physical address of KERNEL_START.
(I tried to match x86's definitions here as per Milton's request to be
consistent).
- k
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2008-04-07 13:00 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2008-04-03 6:29 [PATCH] [POWERPC] Update linker script to properly set physical addresses Kumar Gala
2008-04-07 6:01 ` Paul Mackerras
2008-04-07 13:00 ` Kumar Gala
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).