2006-12-14 09:40:33

by Hirokazu Takata

[permalink] [raw]
Subject: [PATCH 2.6.19] m32r: Fix kernel entry address of vmlinux

This patch fixes the kernel entry point address of vmlinux.

The m32r kernel entry address is 0x08002000 (physical).
But, so far, the ENTRY point written in vmlinux.lds.S was not point
the correct kernel entry address.

(before fix)
$ objdump -x vmlinux
vmlinux: file format elf32-m32r-linux
vmlinux
architecture: m32r2, flags 0x00000112:
EXEC_P, HAS_SYMS, D_PAGED
start address 0x88002090 /* NG */
:
Sections:
Idx Name Size VMA LMA File off Algn
0 .empty_zero_page 00001000 88001000 88001000 00001000 2**12
CONTENTS, ALLOC, LOAD, DATA
1 .boot 0000008c 88002000 88002000 00002000 2**2
CONTENTS, ALLOC, LOAD, READONLY, CODE
2 .text 001ab694 88002090 88002090 00002090 2**4
CONTENTS, ALLOC, LOAD, READONLY, CODE
:

(after fix)
$ objdump -x vmlinux
vmlinux: file format elf32-m32r-linux
vmlinux
architecture: m32r2, flags 0x00000112:
EXEC_P, HAS_SYMS, D_PAGED
start address 0x08002000 /* OK */
:

This fix also remedies the following GDB error message (of gdb-6.4 or after)
at the first operation of kernel debugging:
"Previous frame identical to this frame (corrupt stack?)".

Signed-off-by: Hirokazu Takata <[email protected]>
---
arch/m32r/Makefile | 2 +-
arch/m32r/kernel/vmlinux.lds.S | 5 ++++-
2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/m32r/Makefile b/arch/m32r/Makefile
index f219c47..cdf63b2 100644
--- a/arch/m32r/Makefile
+++ b/arch/m32r/Makefile
@@ -7,7 +7,7 @@

LDFLAGS :=
OBJCOPYFLAGS := -O binary -R .note -R .comment -S
-LDFLAGS_vmlinux := -e startup_32
+LDFLAGS_vmlinux :=

CFLAGS += -pipe -fno-schedule-insns
CFLAGS_KERNEL += -mmodel=medium
diff --git a/arch/m32r/kernel/vmlinux.lds.S b/arch/m32r/kernel/vmlinux.lds.S
index 358b9ce..c497a2f 100644
--- a/arch/m32r/kernel/vmlinux.lds.S
+++ b/arch/m32r/kernel/vmlinux.lds.S
@@ -6,12 +6,15 @@
#include <asm/page.h>

OUTPUT_ARCH(m32r)
-ENTRY(startup_32)
#if defined(__LITTLE_ENDIAN__)
jiffies = jiffies_64;
#else
jiffies = jiffies_64 + 4;
#endif
+
+kernel_entry = boot - 0x80000000;
+ENTRY(kernel_entry)
+
SECTIONS
{
. = CONFIG_MEMORY_START + __PAGE_OFFSET;
--
1.4.4.2

--
Hirokazu Takata <[email protected]>
Linux/M32R Project: http://www.linux-m32r.org/