Build files needed for relocation
This patch builds vmlinux file with relocation sections and contents so
that relocs user space program can extract the required relocation
offsets. This packs final relocatable vmlinux kernel as following:
earlier part of relocation apply code, vmlinux, rest of relocation apply
code.
File make.reloc is used to build the relocatable kernel "vmlinux.reloc".
TODO:
I have not yet integrated building relocatable kernel with kernel
Makefile. I need help to integrate this into kernel build process.
Signed-off-by: Mohan Kumar M <[EMAIL PROTECTED]>
---
Index: linux-2.6.26-rc3/arch/powerpc/Kconfig
===================================================================
--- linux-2.6.26-rc3.orig/arch/powerpc/Kconfig
+++ linux-2.6.26-rc3/arch/powerpc/Kconfig
@@ -317,6 +317,15 @@ config CRASH_DUMP
Don't change this unless you know what you are doing.
+config RELOCATABLE_PPC64
+ bool "Build a relocatable kernel (EXPERIMENTAL)"
+ depends on PPC_MULTIPLATFORM && PPC64 && CRASH_DUMP && EXPERIMENTAL
+ help
+ Build a kernel suitable for use as regular kernel and kdump capture
+ kernel.
+
+ Don't change this unless you know what you are doing.
+
config PHYP_DUMP
bool "Hypervisor-assisted dump (EXPERIMENTAL)"
depends on PPC_PSERIES && EXPERIMENTAL
@@ -656,7 +665,7 @@ config LOWMEM_SIZE
default "0x30000000"
config RELOCATABLE
- bool "Build a relocatable kernel (EXPERIMENTAL)"
+ bool "Build relocatable kernel (EXPERIMENTAL)"
depends on EXPERIMENTAL && ADVANCED_OPTIONS && FLATMEM && FSL_BOOKE
help
This builds a kernel image that is capable of running at the
@@ -776,11 +785,11 @@ config PAGE_OFFSET
default "0xc000000000000000"
config KERNEL_START
hex
- default "0xc000000002000000" if CRASH_DUMP
+ default "0xc000000002000000" if CRASH_DUMP && !RELOCATABLE_PPC64
default "0xc000000000000000"
config PHYSICAL_START
hex
- default "0x02000000" if CRASH_DUMP
+ default "0x02000000" if CRASH_DUMP && !RELOCATABLE_PPC64
default "0x00000000"
endif
Index: linux-2.6.26-rc3/arch/powerpc/Makefile
===================================================================
--- linux-2.6.26-rc3.orig/arch/powerpc/Makefile
+++ linux-2.6.26-rc3/arch/powerpc/Makefile
@@ -69,7 +69,7 @@ override CC += -m$(CONFIG_WORD_SIZE)
override AR := GNUTARGET=elf$(CONFIG_WORD_SIZE)-powerpc $(AR)
endif
-LDFLAGS_vmlinux := -Bstatic
+LDFLAGS_vmlinux := --emit-relocs
CFLAGS-$(CONFIG_PPC64) := -mminimal-toc -mtraceback=none -mcall-aixdesc
CFLAGS-$(CONFIG_PPC32) := -ffixed-r2 -mmultiple
Index: linux-2.6.26-rc3/arch/powerpc/vmlinux.reloc.lds.S
===================================================================
--- /dev/null
+++ linux-2.6.26-rc3/arch/powerpc/vmlinux.reloc.lds.S
@@ -0,0 +1,29 @@
+#include <asm/page.h>
+#include <asm-generic/vmlinux.lds.h>
+
+ENTRY(start_wrap)
+
+OUTPUT_ARCH(powerpc:common)
+/* OUTPUT_ARCH(elf64ppc) */
+SECTIONS
+{
+ . = KERNELBASE;
+
+/*
+ * Text, read only data and other permanent read-only sections
+ */
+ /* Text and gots */
+ .text : {
+ _head = .;
+ *(.text.head)
+ _ehead = .;
+
+ _text = .;
+ *(.vmlinux)
+ _etext = .;
+
+ _reloc = .;
+ *(.text.reloc)
+ _ereloc = .;
+ }
+}
Index: linux-2.6.26-rc3/arch/powerpc/vmlinux.reloc.scr
===================================================================
--- /dev/null
+++ linux-2.6.26-rc3/arch/powerpc/vmlinux.reloc.scr
@@ -0,0 +1,8 @@
+SECTIONS
+{
+ .vmlinux : {
+ input_len = .;
+ *(.data)
+ output_len = . - 8;
+ }
+}
Index: linux-2.6.26-rc3/make.reloc
===================================================================
--- /dev/null
+++ linux-2.6.26-rc3/make.reloc
@@ -0,0 +1,35 @@
+#Makefile for building vmlinux with relocatable information and code.
+
+all: vmlinux.reloc
+
+obj := arch/powerpc
+
+AS = as
+LD = ld
+CC = gcc
+CPP = $(CC) -E
+
+
+$(obj)/relocs : $(obj)/relocs.c
+ $(CC) $(obj)/relocs.c -o $(obj)/relocs
+
+$(obj)/vmlinux.reloc.bin : vmlinux $(obj)/relocs
+ $(obj)/relocs vmlinux > $(obj)/vmlinux.reloc.bin 2>/dev/null
+
+$(obj)/vmlinux.bin: vmlinux
+ objcopy -O binary -R .note -R .comment -S vmlinux $(obj)/vmlinux.bin
+
+$(obj)/vmlinux.bin.all : $(obj)/vmlinux.bin $(obj)/vmlinux.reloc.bin
+ cat $(obj)/vmlinux.bin $(obj)/vmlinux.reloc.bin > $(obj)/vmlinux.bin.all
+
+$(obj)/vmlinux.new : $(obj)/vmlinux.reloc.scr $(obj)/vmlinux.bin.all
+ $(LD) -m elf64ppc -r --format binary --oformat elf64-powerpc -T
$(obj)/vmlinux.reloc.scr $(obj)/vmlinux.bin.all -o $(obj)/vmlinux.new
+
+$(obj)/kernel/reloc_apply.o : $(obj)/kernel/reloc_apply.S
+ $(CC) -m64 -Wp,-MD,arch/powerpc/kernel/.reloc_apply.o.d -nostdinc
-isystem /usr/lib/gcc/powerpc64-suse-linux/4.1.2/include -D__KERNEL__ -Iinclude
-include include/linux/autoconf.h -D__ASSEMBLY__ -Wa,-maltivec -c -o
arch/powerpc/kernel/reloc_apply.o arch/powerpc/kernel/reloc_apply.S
+
+$(obj)/vmlinux.reloc.lds : $(obj)/vmlinux.reloc.lds.S
+ $(CC) -m64 -E -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs
-fno-strict-aliasing -fno-common -Werror-implicit-function-declaration -Os
-msoft-float -pipe -mminimal-toc -mtraceback=none -mcall-aixdesc -mtune=power4
-mno-altivec -mno-spe -funit-at-a-time -mno-string -Wa,-maltivec
-fomit-frame-pointer -fno-stack-protector -Wdeclaration-after-statement
-Wno-pointer-sign -Wp,-MD,arch/powerpc/.vmlinux.reloc.lds.d -nostdinc -isystem
/usr/lib/gcc/powerpc64-suse-linux/4.1.2/include -D__KERNEL__ -Iinclude
-include include/linux/autoconf.h -Upowerpc -P -C -Upowerpc -D__ASSEMBLY__
-o arch/powerpc/vmlinux.reloc.lds arch/powerpc/vmlinux.reloc.lds.S
+
+vmlinux.reloc : $(obj)/vmlinux.reloc.lds $(obj)/vmlinux.new
$(obj)/kernel/reloc_apply.o
+ $(LD) -m elf64ppc -T $(obj)/vmlinux.reloc.lds $(obj)/vmlinux.new
$(obj)/kernel/reloc_apply.o -o vmlinux.reloc
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