1. 根目录:
2. arch
3. xtensa
4. include
5. asm
6. syscall.h

/*
 * include/asm-xtensa/syscall.h
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2001 - 2007 Tensilica Inc.
 */

struct pt_regs;
asmlinkage long xtensa_ptrace(long, long, long, long);
asmlinkage long xtensa_sigreturn(struct pt_regs*);
asmlinkage long xtensa_rt_sigreturn(struct pt_regs*);
asmlinkage long xtensa_shmat(int, char __user *, int);
asmlinkage long xtensa_fadvise64_64(int, int,
				    unsigned long long, unsigned long long);

/* Should probably move to linux/syscalls.h */
struct pollfd;
asmlinkage long sys_pselect6(int n, fd_set __user *inp, fd_set __user *outp,
			     fd_set __user *exp, struct timespec __user *tsp,
			     void __user *sig);
asmlinkage long sys_ppoll(struct pollfd __user *ufds, unsigned int nfds,
			  struct timespec __user *tsp,
			  const sigset_t __user *sigmask,
			  size_t sigsetsize);