[PATCH 2/5] Build files needed for relocation
Mohan Kumar M
mohan at in.ibm.com
Tue Aug 12 18:09:44 EST 2008
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.
TODO:
Relocatable vmlinux image is built in arch/powerpc/boot as vmlinux.reloc.
But it should be built in top level directory of kernel source as vmlinux
instead of vmlinux.reloc
Signed-off-by: Mohan Kumar M <mohan at in.ibm.com>
---
arch/powerpc/Kconfig | 15 ++++++++++--
arch/powerpc/Makefile | 9 ++++++-
arch/powerpc/boot/Makefile | 39 ++++++++++++++++++++++++++++++++--
arch/powerpc/boot/vmlinux.lds.S | 28 +++++++++++++++++++++++++
arch/powerpc/boot/vmlinux.reloc.scr | 8 +++++++
5 files changed, 91 insertions(+), 8 deletions(-)
create mode 100644 arch/powerpc/boot/vmlinux.lds.S
create mode 100644 arch/powerpc/boot/vmlinux.reloc.scr
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 63c9caf..b992bc1 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -332,6 +332,15 @@ 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
@@ -694,7 +703,7 @@ 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
@@ -814,11 +823,11 @@ 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
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 9155c93..1bfdeea 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -63,7 +63,7 @@ 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-$(CONFIG_PPC32) := -ffixed-r2 -mmultiple
@@ -146,11 +146,16 @@ core-$(CONFIG_KVM) += arch/powerpc/kvm/
drivers-$(CONFIG_OPROFILE) += arch/powerpc/oprofile/
# Default to zImage, override when needed
+
+ifneq ($(CONFIG_RELOCATABLE_PPC64),y)
all: zImage
+else
+all: zImage vmlinux.reloc
+endif
CPPFLAGS_vmlinux.lds := -Upowerpc
-BOOT_TARGETS = zImage zImage.initrd uImage zImage% dtbImage% treeImage.% cuImage.% simpleImage.%
+BOOT_TARGETS = zImage vmlinux.reloc zImage.initrd uImage zImage% dtbImage% treeImage.% cuImage.% simpleImage.%
PHONY += $(BOOT_TARGETS)
diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
index 14174aa..a67a701 100644
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile
@@ -17,7 +17,7 @@
# CROSS32_COMPILE is setup as a prefix just like CROSS_COMPILE
# in the toplevel makefile.
-all: $(obj)/zImage
+all: $(obj)/zImage $(obj)/vmlinux.reloc
BOOTCFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
-fno-strict-aliasing -Os -msoft-float -pipe \
@@ -122,18 +122,51 @@ $(patsubst %.S,%.o, $(filter %.S, $(src-boot))): %.o: %.S FORCE
$(obj)/wrapper.a: $(obj-wlib) FORCE
$(call if_changed,bootar)
-hostprogs-y := addnote addRamDisk hack-coff mktree dtc
+hostprogs-y := addnote addRamDisk hack-coff mktree dtc relocs
targets += $(patsubst $(obj)/%,%,$(obj-boot) wrapper.a)
extra-y := $(obj)/wrapper.a $(obj-plat) $(obj)/empty.o \
$(obj)/zImage.lds $(obj)/zImage.coff.lds $(obj)/zImage.ps3.lds
+ifeq ($(CONFIG_RELOCATABLE_PPC64),y)
+extra-y += $(obj)/vmlinux.lds
+endif
+
dtstree := $(srctree)/$(src)/dts
wrapper :=$(srctree)/$(src)/wrapper
-wrapperbits := $(extra-y) $(addprefix $(obj)/,addnote hack-coff mktree dtc) \
+wrapperbits := $(extra-y) $(addprefix $(obj)/,addnote hack-coff mktree dtc relocs) \
$(wrapper) FORCE
+ifeq ($(CONFIG_RELOCATABLE_PPC64),y)
+
+targets += vmlinux.offsets vmlinux.bin vmlinux.bin.all vmlinux.reloc.elf vmlinux.reloc reloc_apply.o vmlinux.lds
+
+OBJCOPYFLAGS_vmlinux.bin := -O binary -R .note -R .comment -S
+$(obj)/vmlinux.bin: vmlinux FORCE
+ $(call if_changed,objcopy)
+
+quiet_cmd_relocbin = BUILD $@
+ cmd_relocbin = cat $(filter-out FORCE,$^) > $@
+
+quiet_cmd_relocs = RELOCS $@
+ cmd_relocs = $(obj)/relocs $< > $@
+
+$(obj)/vmlinux.offsets: vmlinux $(obj)/relocs FORCE
+ $(call if_changed,relocs)
+
+$(obj)/vmlinux.bin.all: $(obj)/vmlinux.bin $(obj)/vmlinux.offsets FORCE
+ $(call if_changed,relocbin)
+
+LDFLAGS_vmlinux.reloc.elf := -T $(obj)/vmlinux.reloc.scr -r --format binary --oformat elf64-powerpc
+$(obj)/vmlinux.reloc.elf: $(obj)/vmlinux.bin.all FORCE
+ $(call if_changed,ld)
+
+LDFLAGS_vmlinux.reloc := -T $(obj)/vmlinux.lds
+$(obj)/vmlinux.reloc: $(obj)/reloc_apply.o $(obj)/vmlinux.reloc.elf FORCE
+ $(call if_changed,ld)
+endif
+
#############
# Bits for building dtc
# DTC_GENPARSER := 1 # Uncomment to rebuild flex/bison output
diff --git a/arch/powerpc/boot/vmlinux.lds.S b/arch/powerpc/boot/vmlinux.lds.S
new file mode 100644
index 0000000..245c667
--- /dev/null
+++ b/arch/powerpc/boot/vmlinux.lds.S
@@ -0,0 +1,28 @@
+#include <asm/page.h>
+#include <asm-generic/vmlinux.lds.h>
+
+ENTRY(start_wrap)
+
+OUTPUT_ARCH(powerpc:common64)
+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 = .;
+ }
+}
diff --git a/arch/powerpc/boot/vmlinux.reloc.scr b/arch/powerpc/boot/vmlinux.reloc.scr
new file mode 100644
index 0000000..7240b6b
--- /dev/null
+++ b/arch/powerpc/boot/vmlinux.reloc.scr
@@ -0,0 +1,8 @@
+SECTIONS
+{
+ .vmlinux : {
+ input_len = .;
+ *(.data)
+ output_len = . - 8;
+ }
+}
--
1.5.4
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