From 4641acc691e7b252c5b0ca8d9afed18a003b8813 Mon Sep 17 00:00:00 2001
From: Dean Camera <dean@fourwalledcubicle.com>
Date: Sun, 30 Sep 2012 14:01:30 +0000
Subject: [PATCH] Add LINKER_RELAXATIONS option to the LUFA BUILD build system
module.
---
LUFA/Build/lufa_build.mk | 38 ++++++++++++++---------
LUFA/DoxygenPages/BuildSystem.txt | 7 +++++
LUFA/DoxygenPages/LUFAPoweredProjects.txt | 2 ++
3 files changed, 32 insertions(+), 15 deletions(-)
diff --git a/LUFA/Build/lufa_build.mk b/LUFA/Build/lufa_build.mk
index 04596c51b..ce76b60df 100644
--- a/LUFA/Build/lufa_build.mk
+++ b/LUFA/Build/lufa_build.mk
@@ -9,7 +9,7 @@
LUFA_BUILD_MODULES += BUILD
LUFA_BUILD_TARGETS += size symbol-sizes all lib elf hex lss clean mostlyclean
LUFA_BUILD_MANDATORY_VARS += TARGET ARCH MCU SRC F_USB LUFA_PATH
-LUFA_BUILD_OPTIONAL_VARS += BOARD OPTIMIZATION C_STANDARD CPP_STANDARD F_CPU C_FLAGS CPP_FLAGS ASM_FLAGS CC_FLAGS LD_FLAGS OBJDIR OBJECT_FILES DEBUG_TYPE DEBUG_LEVEL
+LUFA_BUILD_OPTIONAL_VARS += BOARD OPTIMIZATION C_STANDARD CPP_STANDARD F_CPU C_FLAGS CPP_FLAGS ASM_FLAGS CC_FLAGS LD_FLAGS OBJDIR OBJECT_FILES DEBUG_TYPE DEBUG_LEVEL LINKER_RELAXATIONS
LUFA_BUILD_PROVIDED_VARS +=
LUFA_BUILD_PROVIDED_MACROS +=
@@ -60,6 +60,9 @@ LUFA_BUILD_PROVIDED_MACROS +=
# CC_FLAGS - Common flags to pass to the C/C++ compiler and
# assembler
# LD_FLAGS - Flags to pass to the linker
+# LINKER_RELAXATIONS - Enable or disable linker relaxations to
+# decrease binary size (note: can cause link
+# failures on systems with an unpatched binutils)
# OBJDIR - Directory for the output object and dependency
# files; if equal to ".", the output files will
# be generated in the same folder as the sources
@@ -86,19 +89,20 @@ ERROR_IF_EMPTY ?= $(if $(strip $($(strip $(1)))), , $(error Makefile $(strip $
ERROR_IF_NONBOOL ?= $(if $(filter Y N, $($(strip $(1)))), , $(error Makefile $(strip $(1)) option must be Y or N))
# Default values of optionally user-supplied variables
-BOARD ?= NONE
-OPTIMIZATION ?= s
-F_CPU ?=
-C_STANDARD ?= gnu99
-CPP_STANDARD ?= gnu++98
-C_FLAGS ?=
-CPP_FLAGS ?=
-ASM_FLAGS ?=
-CC_FLAGS ?=
-OBJDIR ?= .
-OBJECT_FILES ?=
-DEBUG_FORMAT ?= dwarf-2
-DEBUG_LEVEL ?= 2
+BOARD ?= NONE
+OPTIMIZATION ?= s
+F_CPU ?=
+C_STANDARD ?= gnu99
+CPP_STANDARD ?= gnu++98
+C_FLAGS ?=
+CPP_FLAGS ?=
+ASM_FLAGS ?=
+CC_FLAGS ?=
+OBJDIR ?= .
+OBJECT_FILES ?=
+DEBUG_FORMAT ?= dwarf-2
+DEBUG_LEVEL ?= 2
+LINKER_RELAXATIONS ?= Y
# Sanity check user supplied values
$(foreach MANDATORY_VAR, $(LUFA_BUILD_MANDATORY_VARS), $(call ERROR_IF_UNSET, $(MANDATORY_VAR)))
@@ -114,6 +118,7 @@ $(call ERROR_IF_EMPTY, CPP_STANDARD)
$(call ERROR_IF_EMPTY, OBJDIR)
$(call ERROR_IF_EMPTY, DEBUG_FORMAT)
$(call ERROR_IF_EMPTY, DEBUG_LEVEL)
+$(call ERROR_IF_NONBOOL, LINKER_RELAXATIONS)
# Determine the utility prefix to use for the selected architecture
ifeq ($(ARCH), AVR8)
@@ -194,7 +199,10 @@ BASE_CPP_FLAGS := -x c++ -O$(OPTIMIZATION) -std=$(CPP_STANDARD)
BASE_ASM_FLAGS := -x assembler-with-cpp
# Create a list of flags to pass to the linker
-BASE_LD_FLAGS := -lm -Wl,-Map=$(TARGET).map,--cref -Wl,--gc-sections -Wl,--relax
+BASE_LD_FLAGS := -lm -Wl,-Map=$(TARGET).map,--cref -Wl,--gc-sections
+ifeq ($(LINKER_RELAXATIONS), Y)
+ BASE_LD_FLAGS += -Wl,--relax
+endif
ifeq ($(ARCH), AVR8)
BASE_LD_FLAGS += -mmcu=$(MCU)
else ifeq ($(ARCH), XMEGA)
diff --git a/LUFA/DoxygenPages/BuildSystem.txt b/LUFA/DoxygenPages/BuildSystem.txt
index 57a01d944..3ee524ba3 100644
--- a/LUFA/DoxygenPages/BuildSystem.txt
+++ b/LUFA/DoxygenPages/BuildSystem.txt
@@ -188,6 +188,13 @@
* <td>Flags to pass to the linker, after the automatically generated flags.</td>
* </tr>
* <tr>
+ * <td><tt>LINKER_RELAXATIONS</tt></td>
+ * <td>Enables or disables linker relaxations when linking the application binary. This can reduce the total size
+ * of the application by replacing full \c CALL instructions with smaller \c RCALL instructions where possible.
+ * \note On some unpatched versions of binutils, this can cause link failures in some circumstances. If you
+ * receive a link error <tt>relocation truncated to fit: R_AVR_13_PCREL</tt>, disable this setting.</td>
+ * </tr>
+ * <tr>
* <td><tt>OBJDIR</tt></td>
* <td>Directory to place the generated object and dependency files. If set to "." the same folder as the source file will be used.
* \note When this option is enabled, all source filenames <b>must</b> be unique.</td>
diff --git a/LUFA/DoxygenPages/LUFAPoweredProjects.txt b/LUFA/DoxygenPages/LUFAPoweredProjects.txt
index f45643299..99a0f26aa 100644
--- a/LUFA/DoxygenPages/LUFAPoweredProjects.txt
+++ b/LUFA/DoxygenPages/LUFAPoweredProjects.txt
@@ -148,6 +148,7 @@
* \li CFFA3000, a CompactFlash interface for the Apple II: http://www.dreher.net/CFforAppleII
* \li Digital Survey Instruments Magnetometer and Pointer: http://www.digitalsurveyinstruments.com/
* \li FinchRobot, a robot designed for educational use: http://www.finchrobot.com/
+ * \li Flysight, a GPS logger for wingsuit pilots: http://flysight.ca/
* \li HummingBird Kit, a robotics learning platform: http://www.hummingbirdkit.com/
* \li Penguino, an Arduino Board With On-Board LUFA Powered Debugger/Programmer: http://wiki.icy.com.au/PenguinoAVR
* \li PIR-1, an IR control interface for consumer electronics: http://www.promixis.com/pir-1.php
@@ -160,6 +161,7 @@
* \li Retrode, a USB Games Console Cartridge Reader: http://www.retrode.org
* \li RFI21.1EU UHF RFID reader: http://www.metra.cz/rfid/uhf-rfid-ctecky/rfi21-1eu-uhf-rfid-ctecka.htm
* \li SmartCardDetective, a Smart Card analysis tool: http://www.smartcarddetective.com/
+ * \li TimelapsePlus, a digital camera time lapse tool: https://github.com/timelapseplus/TimelapsePlus-Firmware
* \li USBTINY-MKII, an AVRISP-MKII Clone AVR Programmer: http://tom-itx.dyndns.org:81/~webpage/boards/USBTiny_Mkii/USBTiny_Mkii_index.php
* \li UDS18B20 USB Temperature sensor: http://toughlog.org/uds18b20/
* \li VMeter, a USB MIDI touch strip controller: http://www.vmeter.net/
--
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