Copy SDK to build location in needed (in case of makefile outside of current directory)

sdk/Makefile.am

 silk_version = 1.0.9
 silk_extracted_directory = SILK_SDK_SRC_v$(silk_version)
 silk_flavour_dir = SILK_SDK_SRC_$(SILK_FLAVOUR)_v$(silk_version)
-silk_src_dir = $(silk_extracted_directory)/${silk_flavour_dir}
+silk_src_dir = $(silk_extracted_directory)/$(silk_flavour_dir)
 silk_lib = libSKP_SILK_SDK.a
 
 
+# For some reason a directory target with no dependency is never executed..
+# Hence, this empty task 'silk_src_dir_echo' fixes the issue.
+silk_src_dir_echo:
+$(silk_src_dir): silk_src_dir_echo
+	mkdir -p $(silk_extracted_directory)
+	cp -r $(srcdir)/$(silk_src_dir) $(silk_extracted_directory)
 
 # Call Skype Makefile to build the library
 all-local: $(silk_src_dir)

sdk/SILK_SDK_SRC_v1.0.9/SILK_SDK_SRC_FIX_v1.0.9/Makefile

+#					
+# Makefile for Silk SDK			
+#
+# Copyright (c) 2012, Skype Limited
+# All rights reserved.
+#
+
+#Platform detection and settings
+
+BUILD_OS := $(shell uname | sed -e 's/^.*Darwin.*/MacOS-X/ ; s/^.*CYGWIN.*/Windows/')
+BUILD_ARCHITECTURE := $(shell uname -m | sed -e 's/i686/i386/')
+
+EXESUFFIX = 
+LIBPREFIX = lib
+LIBSUFFIX = .a
+OBJSUFFIX = .o
+
+CC     = $(TOOLCHAIN_PREFIX)gcc$(TOOLCHAIN_SUFFIX)
+AR     = $(TOOLCHAIN_PREFIX)ar
+RANLIB = $(TOOLCHAIN_PREFIX)ranlib
+CP     = $(TOOLCHAIN_PREFIX)cp
+
+cflags-from-defines    = $(addprefix -D,$(1))
+cflags-from-includes   = $(addprefix -I,$(1))
+ldflags-from-ldlibdirs = $(addprefix -L,$(1))
+ldlibs-from-libs       = $(addprefix -l,$(1))
+
+CFLAGS	+= -Wall -enable-threads -O3
+
+CFLAGS  += $(call cflags-from-defines,$(CDEFINES))
+CFLAGS  += $(call cflags-from-defines,$(ADDED_DEFINES))
+CFLAGS  += $(call cflags-from-includes,$(CINCLUDES))
+LDFLAGS += $(call ldflags-from-ldlibdirs,$(LDLIBDIRS))
+LDLIBS  += $(call ldlibs-from-libs,$(LIBS))
+
+COMPILE.c.cmdline   = $(CC) -c $(CFLAGS) -o $@ $<
+LINK.o.cmdline      = $(LINK.o) $^ $(LDLIBS) -lm -o $@$(EXESUFFIX) 
+ARCHIVE.cmdline     = $(AR) $(ARFLAGS) $@ $^ && $(RANLIB) $@
+
+%$(OBJSUFFIX):%.c
+	$(COMPILE.c.cmdline)
+
+# Directives
+
+CINCLUDES += interface src test
+
+# VPATH e.g. VPATH = src:../headers
+VPATH = ./ \
+        interface \
+        src \
+        test 
+
+# Variable definitions
+LIB_NAME = SKP_SILK_SDK
+TARGET = $(LIBPREFIX)$(LIB_NAME)$(LIBSUFFIX)
+
+SRCS_C = $(wildcard src/*.c)
+
+OBJS := $(patsubst %.c,%$(OBJSUFFIX),$(SRCS_C))
+
+ENCODER_SRCS_C = test/Encoder.c
+ENCODER_OBJS := $(patsubst %.c,%$(OBJSUFFIX),$(ENCODER_SRCS_C))
+
+DECODER_SRCS_C = test/Decoder.c
+DECODER_OBJS := $(patsubst %.c,%$(OBJSUFFIX),$(DECODER_SRCS_C))
+
+SIGNALCMP_SRCS_C = test/signalCompare.c
+SIGNALCMP_OBJS := $(patsubst %.c,%$(OBJSUFFIX),$(SIGNALCMP_SRCS_C))
+
+LIBS = \
+	$(LIB_NAME)
+
+LDLIBDIRS = ./
+
+# Rules
+default: all
+
+all: $(TARGET) encoder decoder signalcompare
+
+lib: $(TARGET)
+
+$(TARGET): $(OBJS)
+	$(ARCHIVE.cmdline)
+
+encoder$(EXESUFFIX): $(ENCODER_OBJS)	
+	$(LINK.o.cmdline)
+
+decoder$(EXESUFFIX): $(DECODER_OBJS)	
+	$(LINK.o.cmdline)
+
+signalcompare$(EXESUFFIX): $(SIGNALCMP_OBJS)	
+	$(LINK.o.cmdline)
+
+clean:
+	$(RM) $(TARGET)* $(OBJS) $(ENCODER_OBJS) $(DECODER_OBJS) \
+		  $(SIGNALCMP_OBJS) $(TEST_OBJS) \
+		  encoder$(EXESUFFIX) decoder$(EXESUFFIX) signalcompare$(EXESUFFIX)
+

sdk/SILK_SDK_SRC_v1.0.9/SILK_SDK_SRC_FLP_v1.0.9/Makefile

+#					
+# Makefile for Silk SDK			
+#
+# Copyright (c) 2012, Skype Limited
+# All rights reserved.
+#
+
+#Platform detection and settings
+
+BUILD_OS := $(shell uname | sed -e 's/^.*Darwin.*/MacOS-X/ ; s/^.*CYGWIN.*/Windows/')
+BUILD_ARCHITECTURE := $(shell uname -m | sed -e 's/i686/i386/')
+
+EXESUFFIX = 
+LIBPREFIX = lib
+LIBSUFFIX = .a
+OBJSUFFIX = .o
+
+CC     = $(TOOLCHAIN_PREFIX)gcc$(TOOLCHAIN_SUFFIX)
+AR     = $(TOOLCHAIN_PREFIX)ar
+RANLIB = $(TOOLCHAIN_PREFIX)ranlib
+CP     = $(TOOLCHAIN_PREFIX)cp
+
+cflags-from-defines    = $(addprefix -D,$(1))
+cflags-from-includes   = $(addprefix -I,$(1))
+ldflags-from-ldlibdirs = $(addprefix -L,$(1))
+ldlibs-from-libs       = $(addprefix -l,$(1))
+
+CFLAGS	+= -Wall -enable-threads -O3
+
+CFLAGS  += $(call cflags-from-defines,$(CDEFINES))
+CFLAGS  += $(call cflags-from-defines,$(ADDED_DEFINES))
+CFLAGS  += $(call cflags-from-includes,$(CINCLUDES))
+LDFLAGS += $(call ldflags-from-ldlibdirs,$(LDLIBDIRS))
+LDLIBS  += $(call ldlibs-from-libs,$(LIBS))
+
+COMPILE.c.cmdline   = $(CC) -c $(CFLAGS) -o $@ $<
+LINK.o.cmdline      = $(LINK.o) $^ $(LDLIBS) -lm -o $@$(EXESUFFIX) 
+ARCHIVE.cmdline     = $(AR) $(ARFLAGS) $@ $^ && $(RANLIB) $@
+
+%$(OBJSUFFIX):%.c
+	$(COMPILE.c.cmdline)
+
+# Directives
+
+CINCLUDES += interface src test
+
+# VPATH e.g. VPATH = src:../headers
+VPATH = ./ \
+        interface \
+        src \
+        test 
+
+# Variable definitions
+LIB_NAME = SKP_SILK_SDK
+TARGET = $(LIBPREFIX)$(LIB_NAME)$(LIBSUFFIX)
+
+SRCS_C = $(wildcard src/*.c)
+
+OBJS := $(patsubst %.c,%$(OBJSUFFIX),$(SRCS_C))
+
+ENCODER_SRCS_C = test/Encoder.c
+ENCODER_OBJS := $(patsubst %.c,%$(OBJSUFFIX),$(ENCODER_SRCS_C))
+
+DECODER_SRCS_C = test/Decoder.c
+DECODER_OBJS := $(patsubst %.c,%$(OBJSUFFIX),$(DECODER_SRCS_C))
+
+SIGNALCMP_SRCS_C = test/signalCompare.c
+SIGNALCMP_OBJS := $(patsubst %.c,%$(OBJSUFFIX),$(SIGNALCMP_SRCS_C))
+
+LIBS = \
+	$(LIB_NAME)
+
+LDLIBDIRS = ./
+
+# Rules
+default: all
+
+all: $(TARGET) encoder decoder signalcompare
+
+lib: $(TARGET)
+
+$(TARGET): $(OBJS)
+	$(ARCHIVE.cmdline)
+
+encoder$(EXESUFFIX): $(ENCODER_OBJS)	
+	$(LINK.o.cmdline)
+
+decoder$(EXESUFFIX): $(DECODER_OBJS)	
+	$(LINK.o.cmdline)
+
+signalcompare$(EXESUFFIX): $(SIGNALCMP_OBJS)	
+	$(LINK.o.cmdline)
+
+clean:
+	$(RM) $(TARGET)* $(OBJS) $(ENCODER_OBJS) $(DECODER_OBJS) \
+		  $(SIGNALCMP_OBJS) $(TEST_OBJS) \
+		  encoder$(EXESUFFIX) decoder$(EXESUFFIX) signalcompare$(EXESUFFIX)
+

sdk/SILK_SDK_SRC_v1.0.9/SILK_SDK_SRC_MIPS_v1.0.9/Makefile

+#					
+# Makefile for Silk SDK			
+#
+# Copyright (c) 2012, Skype Limited
+# All rights reserved.
+#
+
+#Platform detection and settings
+
+BUILD_OS := $(shell uname | sed -e 's/^.*Darwin.*/MacOS-X/ ; s/^.*CYGWIN.*/Windows/')
+
+BUILD_ARCHITECTURE := $(shell uname -m | sed -e 's/i686/i386/')
+
+EXESUFFIX = 
+LIBPREFIX = lib
+LIBSUFFIX = .a
+OBJSUFFIX = .o
+
+CC     = $(TOOLCHAIN_PREFIX)gcc$(TOOLCHAIN_SUFFIX)
+CXX    = $(TOOLCHAIN_PREFIX)g++$(TOOLCHAIN_SUFFIX)
+AR     = $(TOOLCHAIN_PREFIX)ar
+RANLIB = $(TOOLCHAIN_PREFIX)ranlib
+CP     = $(TOOLCHAIN_PREFIX)cp
+
+cppflags-from-defines 	= $(addprefix -D,$(1))
+cppflags-from-includes 	= $(addprefix -I,$(1))
+ldflags-from-ldlibdirs 	= $(addprefix -L,$(1))
+ldlibs-from-libs 	= $(addprefix -l,$(1))
+
+
+# Helper to make MIPS Big Endian testing easier
+ifeq (yes,$(MIPS))
+	CFLAGS += -D_SYSTEM_IS_BIG_ENDIAN -meb -mips32
+endif
+
+ifeq (yes,$(MIPSEL))
+	CFLAGS += -mel -mips32
+	LDFLAGS += -mel -mips32
+endif
+
+
+CFLAGS	+= -Wall -enable-threads -O3
+
+CFLAGS  += $(call cppflags-from-defines,$(CDEFINES))
+CFLAGS  += $(call cppflags-from-defines,$(ADDED_DEFINES))
+CFLAGS  += $(call cppflags-from-includes,$(CINCLUDES))
+LDFLAGS += $(call ldflags-from-ldlibdirs,$(LDLIBDIRS))
+LDLIBS  += $(call ldlibs-from-libs,$(LIBS))
+
+COMPILE.c.cmdline   = $(CC) -c $(CFLAGS) $(ADDED_CFLAGS) -o $@ $<
+COMPILE.S.cmdline   = $(CC) -c $(CFLAGS) $(ADDED_CFLAGS) -o $@ $<
+COMPILE.cpp.cmdline = $(CXX) -c $(CFLAGS) $(ADDED_CFLAGS) -o $@ $<
+LINK.o              = $(CXX) $(LDPREFLAGS) $(LDFLAGS)
+LINK.o.cmdline      = $(LINK.o) $^ $(LDLIBS) -o $@$(EXESUFFIX) 
+ARCHIVE.cmdline     = $(AR) $(ARFLAGS) $@ $^ && $(RANLIB) $@
+
+%$(OBJSUFFIX):%.c
+	$(COMPILE.c.cmdline)
+
+%$(OBJSUFFIX):%.cpp
+	$(COMPILE.cpp.cmdline)
+	
+%$(OBJSUFFIX):%.S
+	$(COMPILE.S.cmdline)	
+
+# Directives
+
+CINCLUDES += interface src test
+
+# VPATH e.g. VPATH = src:../headers
+VPATH = ./ \
+        interface \
+        src \
+        test 
+
+# Variable definitions
+LIB_NAME = SKP_SILK_SDK
+TARGET = $(LIBPREFIX)$(LIB_NAME)$(LIBSUFFIX)
+
+SRCS_C = $(wildcard src/*.c) 
+ifneq (,$(TOOLCHAIN_PREFIX))
+	SRCS_S = $(wildcard src/*.S)
+	OBJS := $(patsubst %.c,%$(OBJSUFFIX),$(SRCS_C)) $(patsubst %.S,%$(OBJSUFFIX),$(SRCS_S))
+else
+	OBJS := $(patsubst %.c,%$(OBJSUFFIX),$(SRCS_C))
+endif
+
+ENCODER_SRCS_C = test/Encoder.c
+ENCODER_OBJS := $(patsubst %.c,%$(OBJSUFFIX),$(ENCODER_SRCS_C))
+
+DECODER_SRCS_C = test/Decoder.c
+DECODER_OBJS := $(patsubst %.c,%$(OBJSUFFIX),$(DECODER_SRCS_C))
+
+SIGNALCMP_SRCS_C = test/signalCompare.c
+SIGNALCMP_OBJS := $(patsubst %.c,%$(OBJSUFFIX),$(SIGNALCMP_SRCS_C))
+
+LIBS = \
+	$(LIB_NAME)
+
+LDLIBDIRS = ./
+
+# Rules
+default: all
+
+all: $(TARGET) encoder decoder signalcompare
+
+lib: $(TARGET)
+
+$(TARGET): $(OBJS)
+	$(ARCHIVE.cmdline)
+
+encoder$(EXESUFFIX): $(ENCODER_OBJS)	
+	$(LINK.o.cmdline)
+
+decoder$(EXESUFFIX): $(DECODER_OBJS)	
+	$(LINK.o.cmdline)
+
+signalcompare$(EXESUFFIX): $(SIGNALCMP_OBJS)	
+	$(LINK.o.cmdline)
+
+clean:
+	$(RM) $(TARGET)* $(OBJS) $(ENCODER_OBJS) $(DECODER_OBJS) \
+		  $(SIGNALCMP_OBJS) $(TEST_OBJS) \
+		  encoder$(EXESUFFIX) decoder$(EXESUFFIX) signalcompare$(EXESUFFIX)
+