[U-Boot] [RESEND][PATCH 23/24] sh: generate position independent code for all platforms

Vladimir Zapolskiy
2016-11-27T22:15:35Z

Finally add fpic compilation option to produce relocatable code.
Note that this requires to define CONFIG_NEEDS_MANUAL_RELOC for all
board files, also relocation support still has some limitations
(e.g. a developer should care not to overwrite the executing code or
memset() with zeroes not yet relocated data on malloc init etc.),
which may be fixed while switching to PIE.

Due to short investigation the architecture code is not ready for PIE
linking, this will require some manipulations with .dyn* sections.

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
---
arch/sh/config.mk | 1 +
arch/sh/cpu/u-boot.lds | 2 +-
2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/sh/config.mk b/arch/sh/config.mk
index 673ed8d..71540c8 100644
--- a/arch/sh/config.mk
+++ b/arch/sh/config.mk
@@ -15,5 +15,6 @@ CONFIG_STANDALONE_LOAD_ADDR += -EB
endif

PLATFORM_CPPFLAGS += -DCONFIG_SH -D__SH__
+PLATFORM_RELFLAGS += -fpic
LDFLAGS_FINAL = --gc-sections
PLATFORM_RELFLAGS += -ffixed-r13
diff --git a/arch/sh/cpu/u-boot.lds b/arch/sh/cpu/u-boot.lds
index f2e48c6..bbf9ff4 100644
--- a/arch/sh/cpu/u-boot.lds
+++ b/arch/sh/cpu/u-boot.lds
@@ -60,7 +60,7 @@ SECTIONS
PROVIDE (_fgot = .);
.got :
{
- *(.got)
+ *(.got.plt) *(.got)
. = ALIGN(4);
} >ram
PROVIDE (_egot = .);
--
2.10.2