[U-Boot] [PATCH V2] arm: config: enforce -fno-pic for gcc
Android's tool chain enable the -mandroid at default. This option will enable the -fpic, which cause uboot compilation failure: " LD u-boot u-boot contains unexpected relocations: R_ARM_ABS32 R_ARM_RELATIVE "
In my testcase, arm-linux-androideabi-gcc-4.9 internally enables '-fpic', so when compiling code, there will be relocation entries using type R_ARM_GOT_BREL and .got section. When linking all the built-in.o using ld, there will be R_ARM_ABS32 relocation entry and .got section in the final u-boot elf image. This can not be handled by u-boot, since u-boot only expects R_ARM_RELATIVE relocation entry. arm-poky-linux-gnueabi-gcc-4.9 default does not enable '-fpic', so there is not .got section and R_ARM_GOT_BREL in built-in.o. And in the final u-boot elf image, all relocation entries are R_ARM_RELATIVE.
we can pass '-fno-pic' to xxx-gcc to disable pic. whether the toolchain internally enables or disables pic, '-fno-pic' can work well.
Signed-off-by: Peng Fan peng.fan@nxp.com Cc: Albert Aribaud albert.u.boot@aribaud.net ---
V2: Drop RFC.
arch/arm/config.mk | 1 + 1 file changed, 1 insertion(+)
diff --git a/arch/arm/config.mk b/arch/arm/config.mk index a3e14a8..8fa57ec 100644 --- a/arch/arm/config.mk +++ b/arch/arm/config.mk @@ -107,6 +107,7 @@ ALL-y += checkarmreloc # instruction. Relocation is not supported for that case, so disable # such usage by requiring word relocations. PLATFORM_CPPFLAGS += $(call cc-option, -mword-relocations) +PLATFORM_CPPFLAGS += $(call cc-option, -fno-pic) endif
# limit ourselves to the sections we want in the .bin.
On Sat, Jan 30, 2016 at 12:10:49PM +0800, Peng Fan wrote:
Android's tool chain enable the -mandroid at default. This option will enable the -fpic, which cause uboot compilation failure: " LD u-boot u-boot contains unexpected relocations: R_ARM_ABS32 R_ARM_RELATIVE "
In my testcase, arm-linux-androideabi-gcc-4.9 internally enables '-fpic', so when compiling code, there will be relocation entries using type R_ARM_GOT_BREL and .got section. When linking all the built-in.o using ld, there will be R_ARM_ABS32 relocation entry and .got section in the final u-boot elf image. This can not be handled by u-boot, since u-boot only expects R_ARM_RELATIVE relocation entry. arm-poky-linux-gnueabi-gcc-4.9 default does not enable '-fpic', so there is not .got section and R_ARM_GOT_BREL in built-in.o. And in the final u-boot elf image, all relocation entries are R_ARM_RELATIVE.
we can pass '-fno-pic' to xxx-gcc to disable pic. whether the toolchain internally enables or disables pic, '-fno-pic' can work well.
Signed-off-by: Peng Fan peng.fan@nxp.com Cc: Albert Aribaud albert.u.boot@aribaud.net
Reviewed-by: Tom Rini trini@konsulko.com
Hello Peng,
On Sat, 30 Jan 2016 12:10:49 +0800, Peng Fan van.freenix@gmail.com wrote:
Android's tool chain enable the -mandroid at default. This option will enable the -fpic, which cause uboot compilation failure: " LD u-boot u-boot contains unexpected relocations: R_ARM_ABS32 R_ARM_RELATIVE "
In my testcase, arm-linux-androideabi-gcc-4.9 internally enables '-fpic', so when compiling code, there will be relocation entries using type R_ARM_GOT_BREL and .got section. When linking all the built-in.o using ld, there will be R_ARM_ABS32 relocation entry and .got section in the final u-boot elf image. This can not be handled by u-boot, since u-boot only expects R_ARM_RELATIVE relocation entry. arm-poky-linux-gnueabi-gcc-4.9 default does not enable '-fpic', so there is not .got section and R_ARM_GOT_BREL in built-in.o. And in the final u-boot elf image, all relocation entries are R_ARM_RELATIVE.
we can pass '-fno-pic' to xxx-gcc to disable pic. whether the toolchain internally enables or disables pic, '-fno-pic' can work well.
Signed-off-by: Peng Fan peng.fan@nxp.com Cc: Albert Aribaud albert.u.boot@aribaud.net
V2: Drop RFC.
arch/arm/config.mk | 1 + 1 file changed, 1 insertion(+)
diff --git a/arch/arm/config.mk b/arch/arm/config.mk index a3e14a8..8fa57ec 100644 --- a/arch/arm/config.mk +++ b/arch/arm/config.mk @@ -107,6 +107,7 @@ ALL-y += checkarmreloc # instruction. Relocation is not supported for that case, so disable # such usage by requiring word relocations. PLATFORM_CPPFLAGS += $(call cc-option, -mword-relocations) +PLATFORM_CPPFLAGS += $(call cc-option, -fno-pic) endif
# limit ourselves to the sections we want in the .bin.
2.6.2
Applied to u-boot-arm/master, thanks!
Amicalement,
participants (3)
-
Albert ARIBAUD -
Peng Fan -
Tom Rini