sys/platform/vkernel64/x86_64/locore.s

   1 /*
   2  * Copyright (c) 2006 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@backplane.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  * $DragonFly: src/sys/platform/vkernel/i386/locore.s,v 1.6 2007/01/08 03:33:43 dillon Exp $
  35  */
  36
  37 #include <sys/syscall.h>
  38 #include <machine/asmacros.h>
  39 #include <machine/psl.h>
  40 #include "assym.s"
  41
  42         /*
  43          * The sysinit and sysuninit sections have to be read-write data
  44          * sections, not read-only data sections.
  45          */
  46         .section        set_sysinit_set, "aw"
  47         .section        set_sysuninit_set, "aw"
  48
  49         .data
  50         ALIGN_DATA              /* just to be sure */
  51
  52         /*
  53          * Normally the startup code would begin here, but this is a
  54          * virtual kernel so we just have a main() in platform/init.c
  55          */
  56
  57         .text
  58 /**********************************************************************
  59  *
  60  * Signal trampoline, copied to top of user stack
  61  *
  62  * arguments: %rdi, %rsi, %rdx, %rcx
  63  */
  64 NON_GPROF_ENTRY(sigcode)
  65         call    *SIGF_HANDLER(%rsp)     /* call signal handler */
  66         lea     SIGF_UC(%rsp),%rdi      /* get ucontext_t */
  67         pushq   $0                      /* junk to fake return addr. */
  68         movq    $SYS_sigreturn,%rax
  69         syscall                         /* enter kernel with args */
  70 0:      hlt                             /* trap priviliged instruction */
  71         jmp     0b
  72
  73         ALIGN_TEXT
  74 esigcode:
  75
  76 /* void reset_dbregs() */
  77 ENTRY(reset_dbregs)
  78         movq    $0x200,%rax   /* the manual says that bit 10 must be set to 1 */
  79         movq    %rax,%dr7     /* disable all breapoints first */
  80         movq    $0,%rax
  81         movq    %rax,%dr0
  82         movq    %rax,%dr1
  83         movq    %rax,%dr2
  84         movq    %rax,%dr3
  85         movq    %rax,%dr6
  86         ret
  87
  88         .data
  89         .globl  szsigcode
  90 szsigcode:
  91         .long   esigcode - sigcode