/*
 * Copyright 2018, Jérôme Duval. All rights reserved.
 * Distributed under the terms of the MIT License.
 */


#include <asm_defs.h>


.text

/* user space half of the syscall mechanism, to be copied into the commpage */


// Intel sysenter/sysexit
FUNCTION(x86_user_syscall_sysenter):
        // sysexit forces us to trash edx (-> eip) and ecx (-> esp), but they are
        // scratch registers anyway. We use ecx right away to store esp.
        movl    %esp, %ecx
        sysenter
        ret
FUNCTION_END(x86_user_syscall_sysenter)
SYMBOL(x86_user_syscall_sysenter_end):


// AMD syscall/sysret
FUNCTION(x86_user_syscall_syscall):
        syscall
        ret
FUNCTION_END(x86_user_syscall_syscall)
SYMBOL(x86_user_syscall_syscall_end):