1. 根目录:
2. arch
3. arm
4. include
5. asm
6. linkage.h

#ifndef __ASM_LINKAGE_H
#define __ASM_LINKAGE_H

#define __ALIGN .align 0
#define __ALIGN_STR ".align 0"

#define ENDPROC(name) \
  .type name, %function; \
  END(name)

#endif