[TOOLCHAIN] Hosted toolchain with musl libc

libc/Makefile

@@ -0,0 +1,30 @@
+ifeq ($(MITTOS64),)
+  $(error Build environment is not activated. Please source activate)
+endif
+
+LIBDIR := $(SYSROOT)/usr/lib
+
+CRT := crt0
+CRT_OBJ := $(addprefix obj/, $(patsubst %,%.o,$(CRT)))
+
+ASFLAGS := -ggdb
+
+all: $(CRT_OBJ)
+
+OBJ_DIRS := $(sort $(dir $(CRT_OBJ)))
+$(CRT_OBJ): | $(OBJ_DIRS)
+$(OBJ_DIRS):
+	mkdir -p $@
+
+obj/%.o:%.S
+	$(COMPILE.S) $^ -o $@
+
+$(LIBDIR)/%: obj/%
+	cp $< $@
+
+install: $(patsubst %,$(LIBDIR)/%.o,$(CRT))
+
+clean:
+	rm -rf obj/
+
+.PHONY: all clean install

libc/crt0.S

@@ -0,0 +1,25 @@
+ .intel_syntax noprefix
+ .section .text
+ .global _start
+
+ _start:
+  movq rbp, 0
+  push rbp
+  push rbp
+  mov rbp, rsp
+
+  push rsi
+  push rdi
+
+  call _init
+
+  pop rdi
+  pop rsi
+
+  call main
+
+  call _fini
+
+  jmp $
+
+.size _start, . - _start