src/lwp/process.i386.s

   1 /*
   2  * Copyright 2000, International Business Machines Corporation and others.
   3  * All Rights Reserved.
   4  *
   5  * This software has been released under the terms of the IBM Public
   6  * License.  For details, see the LICENSE file in the top-level source
   7  * directory or online at http://www.openafs.org/dl/license10.html
   8  */
   9
  10 /* Sun 386i... I hope this does the right thing!!!
  11  *
  12  * Written by Derek Atkins <warlord@MIT.EDU>
  13  * (debugging help by Chris Provenzano <proven@mit.edu>)
  14  * 11/1991
  15  *
  16  * "ojala que es correcto!"
  17  */
  18
  19 #include <lwp_elf.h>
  20
  21         .file "process.s"
  22
  23         .data
  24
  25         .text
  26
  27 /*
  28  * struct savearea {
  29  *      char    *topstack;
  30  * }
  31  */
  32
  33         .set    topstack,0
  34
  35 /*
  36  * savecontext(f, area1, newsp)
  37  *      int (*f)(); struct savearea *area1; char *newsp;
  38  */
  39
  40 /* offsets, to make my life easier! */
  41         .set    f,8
  42         .set    area1,12
  43         .set    newsp,16
  44
  45 .globl  _C_LABEL(PRE_Block)
  46 .globl  _C_LABEL(savecontext)
  47
  48 ENTRY(savecontext)
  49         pushl   %ebp                    /* New Frame! */
  50         movl    %esp,%ebp
  51         pusha                           /* Push all registers */
  52         movl    $1,_C_LABEL(PRE_Block)  /* Pre-emption code */
  53         movl    area1(%ebp),%eax        /* eax = base of savearea */
  54         movl    %esp,(%eax)             /* area->topstack = esp */
  55         movl    newsp(%ebp),%eax        /* get new sp into eax */
  56         cmpl    $0,%eax
  57         je      L1                      /* if new sp is 0 then dont change esp */
  58         movl    %eax,%esp               /* go ahead.  make my day! */
  59 L1:
  60         jmp     *f(%ebp)                        /* ebx = &f */
  61
  62 /*
  63  * returnto(area2)
  64  *      struct savearea *area2;
  65  */
  66
  67 /* stack offset */
  68         .set    area2,8
  69
  70 .globl  _C_LABEL(returnto)
  71
  72 ENTRY(returnto)
  73         pushl   %ebp
  74         movl    %esp, %ebp              /* New frame, to get correct pointer */
  75         movl    area2(%ebp),%eax        /* eax = area2 */
  76         movl    (%eax),%esp             /* restore esp */
  77         popa
  78         movl    $0,_C_LABEL(PRE_Block)          /* clear it up... */
  79         popl    %ebp
  80         ret
  81
  82 #if defined(__linux__) && defined(__ELF__)
  83         .section .note.GNU-stack,"",%progbits
  84 #endif