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sortix--sortix/libc/include/sys/syscall.h
2013-12-17 14:30:23 +01:00

102 lines
3.4 KiB
C

/*******************************************************************************
Copyright(C) Jonas 'Sortie' Termansen 2011, 2012, 2013.
This file is part of the Sortix C Library.
The Sortix C Library is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation, either version 3 of the License, or (at your
option) any later version.
The Sortix C Library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
License for more details.
You should have received a copy of the GNU Lesser General Public License
along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
sys/syscall.h
Functions and macros for declaring system call stubs.
*******************************************************************************/
#if defined(SORTIX_KERNEL)
#error "This file is part of user-space and should not be built in kernel mode"
#endif
#ifndef _SYS_SYSCALL_H
#define _SYS_SYSCALL_H 1
#include <features.h>
#include <sortix/syscallnum.h>
/* Expand a macro and convert it to string. */
#define SYSCALL_STRINGIFY_EXPAND(foo) #foo
/* Implement the body of a function that selects the right system call and
jumps into the generic implementation of system calls. */
#if defined(__i386__)
#define SYSCALL_FUNCTION_BODY(syscall_index) \
" mov $" SYSCALL_STRINGIFY_EXPAND(syscall_index) ", %eax\n" \
" jmp asm_syscall\n"
#elif defined(__x86_64__)
#define SYSCALL_FUNCTION_BODY(syscall_index) \
" mov $" SYSCALL_STRINGIFY_EXPAND(syscall_index) ", %rax\n" \
" jmp asm_syscall\n"
#else
#error Provide an implementation for your platform.
#endif
/* Create a function that selects the right system call and jumps into the
generic implementation of system calls. */
#define SYSCALL_FUNCTION(syscall_name, syscall_index) \
asm("\n" \
".pushsection .text\n" \
".type " #syscall_name ", @function\n" \
#syscall_name ":\n" \
SYSCALL_FUNCTION_BODY(syscall_index) \
".popsection\n" \
);
/* Create a function that performs the system call by injecting the right
instructions into the compiler assembly output. Then provide a declaration of
the function that looks just like the caller wants it. */
#define DEFINE_SYSCALL(syscall_type, syscall_name, syscall_index, syscall_formals) \
SYSCALL_FUNCTION(syscall_name, syscall_index) \
__BEGIN_DECLS \
extern "C" { syscall_type syscall_name syscall_formals; } \
__END_DECLS \
/* System call accepting no parameters. */
#define DEFN_SYSCALL0(type, fn, num) \
DEFINE_SYSCALL(type, fn, num, ())
/* System call accepting 1 parameter. */
#define DEFN_SYSCALL1(type, fn, num, t1) \
DEFINE_SYSCALL(type, fn, num, (t1 p1))
/* System call accepting 2 parameters. */
#define DEFN_SYSCALL2(type, fn, num, t1, t2) \
DEFINE_SYSCALL(type, fn, num, (t1 p1, t2 p2))
/* System call accepting 3 parameters. */
#define DEFN_SYSCALL3(type, fn, num, t1, t2, t3) \
DEFINE_SYSCALL(type, fn, num, (t1 p1, t2 p2, t3 p3))
/* System call accepting 4 parameters. */
#define DEFN_SYSCALL4(type, fn, num, t1, t2, t3, t4) \
DEFINE_SYSCALL(type, fn, num, (t1 p1, t2 p2, t3 p3, t4 p4))
/* System call accepting 5 parameters. */
#define DEFN_SYSCALL5(type, fn, num, t1, t2, t3, t4, t5) \
DEFINE_SYSCALL(type, fn, num, (t1 p1, t2 p2, t3 p3, t4 p4, t5 p5))
#endif