syscall.c

Go to the documentation of this file.
00001 /*
00002  * Copyright (C) 2006 Ondrej Palkovsky
00003  * All rights reserved.
00004  *
00005  * Redistribution and use in source and binary forms, with or without
00006  * modification, are permitted provided that the following conditions
00007  * are met:
00008  *
00009  * - Redistributions of source code must retain the above copyright
00010  *   notice, this list of conditions and the following disclaimer.
00011  * - Redistributions in binary form must reproduce the above copyright
00012  *   notice, this list of conditions and the following disclaimer in the
00013  *   documentation and/or other materials provided with the distribution.
00014  * - The name of the author may not be used to endorse or promote products
00015  *   derived from this software without specific prior written permission.
00016  *
00017  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
00018  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
00019  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
00020  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
00021  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
00022  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
00023  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
00024  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
00025  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
00026  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00027  */
00028 
00035 #include <syscall/syscall.h>
00036 #include <arch/syscall.h>
00037 #include <panic.h>
00038 #include <arch/cpu.h>
00039 #include <arch/pm.h>
00040 #include <arch/asm.h>
00041 
00042 #include <print.h>
00043 #include <arch/cpu.h>
00044 
00045 extern void syscall_entry(void);
00046 
00048 void syscall_setup_cpu(void)
00049 {
00050         /* Enable SYSCALL/SYSRET */
00051         set_efer_flag(AMD_SCE_FLAG);
00052 
00053         /* Setup syscall entry address */
00054         
00055         /* This is _mess_ - the 64-bit CS is argument+16,
00056          * the SS is argument+8. The order is:
00057          * +0(KDATA_DES), +8(UDATA_DES), +16(UTEXT_DES)
00058          */
00059         write_msr(AMD_MSR_STAR,
00060                   ((__u64)(gdtselector(KDATA_DES) | PL_USER)<<48) \
00061                   | ((__u64)(gdtselector(KTEXT_DES) | PL_KERNEL)<<32));
00062         write_msr(AMD_MSR_LSTAR, (__u64)syscall_entry);
00063         /* Mask RFLAGS on syscall 
00064          * - disable interrupts, until we exchange the stack register
00065          *   (mask the IE bit)
00066          */
00067         write_msr(AMD_MSR_SFMASK, 0x200);
00068 }
00069 

Generated on Sun Jun 18 16:26:58 2006 for HelenOS Kernel (amd64) by  doxygen 1.4.6