Makefile: use -f{function,data}-sections, don’t rename sections

Platform- and application-specific section placement is best done in
the application makefiles and linker scripts. On the other hand,
compiling with split sections allows code and data usage to be reduced
without tuning specific options in config file.

Author: igrr

Makefile

@@ -43,6 +43,8 @@ CFLAGS+=-std=c99 -DESP8266
 
 CFLAGS += -Wall -Os -g -O2 -Wpointer-arith -Wl,-EL -nostdlib -mlongcalls -mno-text-section-literals  -D__ets__ -DICACHE_FLASH
 
+CFLAGS += -ffunction-sections -fdata-sections
+
 MFORCE32 := $(shell $(CC) --help=target | grep mforce-l32)
 ifneq ($(MFORCE32),)
     # If the compiler supports the -mforce-l32 flag, the compiler will generate correct code for loading
@@ -62,12 +64,6 @@ all: $(AXTLS_AR)
 $(AXTLS_AR): | $(BIN_DIR)
 
 $(AXTLS_AR): $(OBJ_FILES)
-	for file in $(OBJ_FILES); do \
-		$(OBJCOPY) \
-		--rename-section .text=.irom0.text \
-		--rename-section .literal=.irom0.literal \
-		$$file; \
-	done
 	$(AR) cru $@ $^
 
 $(BIN_DIR):