Update Makefile

add sh-elf toolchain support

Makefile

@@ -18,7 +18,7 @@ endif
 
 cflags := -m3 -mb -ffreestanding -nostdlib -fstrict-volatile-bitfields -Wall \
           -Wextra -Os -I . $(modelflag)
-target ?= sh3eb-elf
+target ?= sh-elf
 lib    := liblog-$(MODEL).a
 header := liblog.h
 
@@ -45,7 +45,8 @@ build-$(MODEL)/%.c.o: %.c | build-$(MODEL)/
 # Misc rules
 
 clean:
-	@ rm -rf build
+	@ rm -rf build-fx
+	@ rm -rf build-cg
 distclean: clean
 	@ rm -f $(lib)