efi: efistub: Convert into static library

This patch changes both x86 and arm64 efistub implementations
from #including shared .c files under drivers/firmware/efi to
building shared code as a static library.

The x86 code uses a stub built into the boot executable which
uncompresses the kernel at boot time. In this case, the library is
linked into the decompressor.

In the arm64 case, the stub is part of the kernel proper so the library
is linked into the kernel proper as well.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 2cc14ce..3a0a4ce 100644 (file)
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -292,6 +292,9 @@ config CMDLINE_FORCE
          This is useful if you cannot or don't want to change the
          command-line options your boot loader passes to the kernel.
 
+config EFI_STUB
+       bool
+
 config EFI
        bool "UEFI runtime support"
        depends on OF && !CPU_BIG_ENDIAN
@@ -299,6 +302,8 @@ config EFI
        select UCS2_STRING
        select EFI_PARAMS_FROM_FDT
        select EFI_RUNTIME_WRAPPERS
+       select EFI_STUB
+       select EFI_ARMSTUB
        default y
        help
          This option provides support for runtime services provided

diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 8185a91..5836717 100644 (file)
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -48,6 +48,7 @@ core-$(CONFIG_XEN) += arch/arm64/xen/
 core-$(CONFIG_CRYPTO) += arch/arm64/crypto/
 libs-y         := arch/arm64/lib/ $(libs-y)
 libs-y         += $(LIBGCC)
+libs-$(CONFIG_EFI_STUB) += drivers/firmware/efi/libstub/
 
 # Default target when executing plain make
 KBUILD_IMAGE   := Image.gz

diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index cdaedad..afaeb73 100644 (file)
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -4,8 +4,7 @@
 
 CPPFLAGS_vmlinux.lds   := -DTEXT_OFFSET=$(TEXT_OFFSET)
 AFLAGS_head.o          := -DTEXT_OFFSET=$(TEXT_OFFSET)
-CFLAGS_efi-stub.o      := -DTEXT_OFFSET=$(TEXT_OFFSET) \
-                          -I$(src)/../../../scripts/dtc/libfdt
+CFLAGS_efi-stub.o      := -DTEXT_OFFSET=$(TEXT_OFFSET)
 
 CFLAGS_REMOVE_ftrace.o = -pg
 CFLAGS_REMOVE_insn.o = -pg

diff --git a/arch/arm64/kernel/efi-stub.c b/arch/arm64/kernel/efi-stub.c
index e499902..1317fef 100644 (file)
--- a/arch/arm64/kernel/efi-stub.c
+++ b/arch/arm64/kernel/efi-stub.c
@@ -13,12 +13,6 @@
 #include <asm/efi.h>
 #include <asm/sections.h>
 
-/* Include shared EFI stub code */
-#include "../../../drivers/firmware/efi/efi-stub-helper.c"
-#include "../../../drivers/firmware/efi/fdt.c"
-#include "../../../drivers/firmware/efi/arm-stub.c"
-
-
 efi_status_t handle_kernel_image(efi_system_table_t *sys_table,
                                 unsigned long *image_addr,
                                 unsigned long *image_size,

diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index 0fcd913..7a801a3 100644 (file)
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -33,7 +33,8 @@ VMLINUX_OBJS = $(obj)/vmlinux.lds $(obj)/head_$(BITS).o $(obj)/misc.o \
 $(obj)/eboot.o: KBUILD_CFLAGS += -fshort-wchar -mno-red-zone
 
 ifeq ($(CONFIG_EFI_STUB), y)
-       VMLINUX_OBJS += $(obj)/eboot.o $(obj)/efi_stub_$(BITS).o
+       VMLINUX_OBJS += $(obj)/eboot.o $(obj)/efi_stub_$(BITS).o \
+                               $(objtree)/drivers/firmware/efi/libstub/lib.a
 endif
 
 $(obj)/vmlinux: $(VMLINUX_OBJS) FORCE

diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index 916bbdd..3b5c66c 100644 (file)
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -280,8 +280,6 @@ void efi_char16_printk(efi_system_table_t *table, efi_char16_t *str)
        }
 }
 
-#include "../../../../drivers/firmware/efi/efi-stub-helper.c"
-
 static void find_bits(unsigned long mask, u8 *pos, u8 *size)
 {
        u8 first, len;

diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig
index 588dc47..f712d47 100644 (file)
--- a/drivers/firmware/efi/Kconfig
+++ b/drivers/firmware/efi/Kconfig
@@ -57,6 +57,9 @@ config EFI_PARAMS_FROM_FDT
 config EFI_RUNTIME_WRAPPERS
        bool
 
+config EFI_ARMSTUB
+       bool
+
 endmenu
 
 config UEFI_CPER

diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile
index e109653..a204d14 100644 (file)
--- a/drivers/firmware/efi/Makefile
+++ b/drivers/firmware/efi/Makefile
@@ -7,3 +7,4 @@ obj-$(CONFIG_EFI_VARS_PSTORE)           += efi-pstore.o
 obj-$(CONFIG_UEFI_CPER)                        += cper.o
 obj-$(CONFIG_EFI_RUNTIME_MAP)          += runtime-map.o
 obj-$(CONFIG_EFI_RUNTIME_WRAPPERS)     += runtime-wrappers.o
+obj-$(CONFIG_EFI_STUB)                 += libstub/

diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
new file mode 100644 (file)
index 0000000..b14bc2b
--- /dev/null
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -0,0 +1,26 @@
+#
+# The stub may be linked into the kernel proper or into a separate boot binary,
+# but in either case, it executes before the kernel does (with MMU disabled) so
+# things like ftrace and stack-protector are likely to cause trouble if left
+# enabled, even if doing so doesn't break the build.
+#
+cflags-$(CONFIG_X86_32)                := -march=i386
+cflags-$(CONFIG_X86_64)                := -mcmodel=small
+cflags-$(CONFIG_X86)           += -m$(BITS) -D__KERNEL__ $(LINUX_INCLUDE) -O2 \
+                                  -fPIC -fno-strict-aliasing -mno-red-zone \
+                                  -mno-mmx -mno-sse -DDISABLE_BRANCH_PROFILING
+
+cflags-$(CONFIG_ARM64)         := $(subst -pg,,$(KBUILD_CFLAGS))
+cflags-$(CONFIG_ARM)           := $(subst -pg,,$(KBUILD_CFLAGS)) \
+                                  -fno-builtin -fpic -mno-single-pic-base
+
+KBUILD_CFLAGS                  := $(cflags-y) \
+                                  $(call cc-option,-ffreestanding) \
+                                  $(call cc-option,-fno-stack-protector)
+
+GCOV_PROFILE                   := n
+
+lib-y                          := efi-stub-helper.o
+lib-$(CONFIG_EFI_ARMSTUB)      += arm-stub.o fdt.o
+
+CFLAGS_fdt.o                   += -I$(srctree)/scripts/dtc/libfdt/

diff --git a/drivers/firmware/efi/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c
similarity index 100%
rename from drivers/firmware/efi/arm-stub.c
rename to drivers/firmware/efi/libstub/arm-stub.c

diff --git a/drivers/firmware/efi/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c
similarity index 100%
rename from drivers/firmware/efi/efi-stub-helper.c
rename to drivers/firmware/efi/libstub/efi-stub-helper.c

diff --git a/drivers/firmware/efi/efistub.h b/drivers/firmware/efi/libstub/efistub.h
similarity index 100%
rename from drivers/firmware/efi/efistub.h
rename to drivers/firmware/efi/libstub/efistub.h

diff --git a/drivers/firmware/efi/fdt.c b/drivers/firmware/efi/libstub/fdt.c
similarity index 100%
rename from drivers/firmware/efi/fdt.c
rename to drivers/firmware/efi/libstub/fdt.c