From 776cf5543b567f781b1b87c31ade51cb04c98e8f Mon Sep 17 00:00:00 2001
From: Siarhei Siamashka <siarhei.siamashka@gmail.com>
Date: Fri, 6 May 2016 06:46:27 +0300
Subject: [PATCH] Fix compatibility with Linaro toolchains for building ARM
 binaries

Add DISCARD directives to the linker scripts and also -marm option
to GCC command line. Without this, certain toolchains may build
Thumb2 code by default. Also junk sections may be present in the
final binary and they need to be removed.

This helps at least when using the following Linaro toolchain:
gcc-linaro-5.1-2015.08-x86_64_arm-linux-gnueabihf.tar.xz

Signed-off-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>
Reviewed-by: Bernhard Nortmann <bernhard.nortmann@web.de>
---
 Makefile       |  2 +-
 boot_head.lds  | 17 +++++++++++------
 fel-pio.lds    | 17 +++++++++++------
 fel-sdboot.lds | 17 +++++++++++------
 jtag-loop.lds  | 17 +++++++++++------
 5 files changed, 45 insertions(+), 25 deletions(-)

diff --git a/Makefile b/Makefile
index 59e8641..e1dcb8a 100644
--- a/Makefile
+++ b/Makefile
@@ -121,7 +121,7 @@ sunxi-%: %.c
 
 fel-pio.bin: fel-pio.elf fel-pio.nm
 
-ARM_ELF_FLAGS = -Os -fpic -Wall
+ARM_ELF_FLAGS = -Os -marm -fpic -Wall
 ARM_ELF_FLAGS += -fno-common -fno-builtin -ffreestanding -nostdinc
 ARM_ELF_FLAGS += -mno-thumb-interwork -fno-stack-protector -fno-toplevel-reorder
 ARM_ELF_FLAGS += -Wstrict-prototypes -Wno-format-nonliteral -Wno-format-security
diff --git a/boot_head.lds b/boot_head.lds
index 278f530..4fdbc6d 100644
--- a/boot_head.lds
+++ b/boot_head.lds
@@ -14,10 +14,15 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-     SECTIONS
-     {
-       . = 0x40007000;
-       .text : { *(.text) }
-     }
-
 
+SECTIONS
+{
+	. = 0x40007000;
+	.text : { *(.text) }
+	/DISCARD/ : { *(.dynstr*) }
+	/DISCARD/ : { *(.dynamic*) }
+	/DISCARD/ : { *(.plt*) }
+	/DISCARD/ : { *(.interp*) }
+	/DISCARD/ : { *(.gnu*) }
+	/DISCARD/ : { *(.note*) }
+}
diff --git a/fel-pio.lds b/fel-pio.lds
index 618070c..f35da1a 100644
--- a/fel-pio.lds
+++ b/fel-pio.lds
@@ -14,10 +14,15 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-     SECTIONS
-     {
-       . = 0x2000;
-       .text : { *(.text) }
-     }
-
 
+SECTIONS
+{
+	. = 0x2000;
+	.text : { *(.text) }
+	/DISCARD/ : { *(.dynstr*) }
+	/DISCARD/ : { *(.dynamic*) }
+	/DISCARD/ : { *(.plt*) }
+	/DISCARD/ : { *(.interp*) }
+	/DISCARD/ : { *(.gnu*) }
+	/DISCARD/ : { *(.note*) }
+}
diff --git a/fel-sdboot.lds b/fel-sdboot.lds
index 67bff97..9ba718d 100644
--- a/fel-sdboot.lds
+++ b/fel-sdboot.lds
@@ -14,10 +14,15 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-     SECTIONS
-     {
-       . = 0x0030;
-       .text : { *(.text) }
-     }
-
 
+SECTIONS
+{
+	. = 0x0030;
+	.text : { *(.text) }
+	/DISCARD/ : { *(.dynstr*) }
+	/DISCARD/ : { *(.dynamic*) }
+	/DISCARD/ : { *(.plt*) }
+	/DISCARD/ : { *(.interp*) }
+	/DISCARD/ : { *(.gnu*) }
+	/DISCARD/ : { *(.note*) }
+}
diff --git a/jtag-loop.lds b/jtag-loop.lds
index 67bff97..9ba718d 100644
--- a/jtag-loop.lds
+++ b/jtag-loop.lds
@@ -14,10 +14,15 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-     SECTIONS
-     {
-       . = 0x0030;
-       .text : { *(.text) }
-     }
-
 
+SECTIONS
+{
+	. = 0x0030;
+	.text : { *(.text) }
+	/DISCARD/ : { *(.dynstr*) }
+	/DISCARD/ : { *(.dynamic*) }
+	/DISCARD/ : { *(.plt*) }
+	/DISCARD/ : { *(.interp*) }
+	/DISCARD/ : { *(.gnu*) }
+	/DISCARD/ : { *(.note*) }
+}