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Commit 6520fe55 authored by H. Peter Anvin's avatar H. Peter Anvin
Browse files

x86, realmode: 16-bit real-mode code support for relocs tool 



A new option is added to the relocs tool called '--realmode'.
This option causes the generation of 16-bit segment relocations
and 32-bit linear relocations for the real-mode code. When
the real-mode code is moved to the low-memory during kernel
initialization, these relocation entries can be used to
relocate the code properly.

In the assembly code 16-bit segment relocations must be relative
to the 'real_mode_seg' absolute symbol. Linear relocations must be
relative to a symbol prefixed with 'pa_'.

16-bit segment relocation is used to load cs:ip in 16-bit code.
Linear relocations are used in the 32-bit code for relocatable
data references. They are declared in the linker script of the
real-mode code.

The relocs tool is moved to arch/x86/tools/relocs.c, and added new
target archscripts that can be used to build scripts needed building
an architecture.  be compiled before building the arch/x86 tree.

[ hpa: accelerating this because it detects invalid absolute
  relocations, a serious bug in binutils 2.22.52.0.x which currently
  produces bad kernels. ]

Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-2-git-send-email-jarkko.sakkinen@intel.com


Signed-off-by: default avatarJarkko Sakkinen <jarkko.sakkinen@intel.com>
Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org>
parent 36be5051

Makefile

+6 −3
Original line number Diff line number Diff line
@@ -442,7 +442,7 @@ asm-generic: 


no-dot-config-targets := clean mrproper distclean \

			 cscope gtags TAGS tags help %docs check% coccicheck \

			 include/linux/version.h headers_% archheaders \

			 include/linux/version.h headers_% archheaders archscripts \

			 kernelversion %src-pkg



config-targets := 0
@@ -979,7 +979,7 @@ prepare1: prepare2 include/linux/version.h include/generated/utsrelease.h \ 
                   include/config/auto.conf

	$(cmd_crmodverdir)



archprepare: archheaders prepare1 scripts_basic

archprepare: archheaders archscripts prepare1 scripts_basic



prepare0: archprepare FORCE

	$(Q)$(MAKE) $(build)=.
@@ -1049,8 +1049,11 @@ hdr-dst = $(if $(KBUILD_HEADERS), dst=include/asm-$(hdr-arch), dst=include/asm) 
PHONY += archheaders

archheaders:



PHONY += archscripts

archscripts:



PHONY += __headers

__headers: include/linux/version.h scripts_basic asm-generic archheaders FORCE

__headers: include/linux/version.h scripts_basic asm-generic archheaders archscripts FORCE

	$(Q)$(MAKE) $(build)=scripts build_unifdef



PHONY += headers_install_all

arch/x86/Makefile

+3 −0
Original line number Diff line number Diff line
@@ -134,6 +134,9 @@ KBUILD_CFLAGS += $(call cc-option,-mno-avx,) 
KBUILD_CFLAGS += $(mflags-y)

KBUILD_AFLAGS += $(mflags-y)



archscripts:

	$(Q)$(MAKE) $(build)=arch/x86/tools relocs



###

# Syscall table generation

arch/x86/boot/compressed/Makefile

+4 −5
Original line number Diff line number Diff line
@@ -40,13 +40,12 @@ OBJCOPYFLAGS_vmlinux.bin := -R .comment -S 
$(obj)/vmlinux.bin: vmlinux FORCE

	$(call if_changed,objcopy)



targets += vmlinux.bin.all vmlinux.relocs



targets += vmlinux.bin.all vmlinux.relocs relocs

hostprogs-$(CONFIG_X86_NEED_RELOCS) += relocs



CMD_RELOCS = arch/x86/tools/relocs

quiet_cmd_relocs = RELOCS  $@

      cmd_relocs = $(obj)/relocs $< > $@;$(obj)/relocs --abs-relocs $<

$(obj)/vmlinux.relocs: vmlinux $(obj)/relocs FORCE

      cmd_relocs = $(CMD_RELOCS) $< > $@;$(CMD_RELOCS) --abs-relocs $<

$(obj)/vmlinux.relocs: vmlinux FORCE

	$(call if_changed,relocs)



vmlinux.bin.all-y := $(obj)/vmlinux.bin

arch/x86/tools/.gitignore

0 → 100644
+1 −0
Original line number Diff line number Diff line 
relocs

arch/x86/tools/Makefile

+4 −0
Original line number Diff line number Diff line
@@ -36,3 +36,7 @@ HOSTCFLAGS_insn_sanity.o := -Wall -I$(objtree)/arch/x86/lib/ -I$(srctree)/arch/x 
$(obj)/test_get_len.o: $(srctree)/arch/x86/lib/insn.c $(srctree)/arch/x86/lib/inat.c $(srctree)/arch/x86/include/asm/inat_types.h $(srctree)/arch/x86/include/asm/inat.h $(srctree)/arch/x86/include/asm/insn.h $(objtree)/arch/x86/lib/inat-tables.c



$(obj)/insn_sanity.o: $(srctree)/arch/x86/lib/insn.c $(srctree)/arch/x86/lib/inat.c $(srctree)/arch/x86/include/asm/inat_types.h $(srctree)/arch/x86/include/asm/inat.h $(srctree)/arch/x86/include/asm/insn.h $(objtree)/arch/x86/lib/inat-tables.c



HOST_EXTRACFLAGS += -I$(srctree)/tools/include

hostprogs-y	+= relocs

relocs: $(obj)/relocs