Rev 2071 | Details | Compare with Previous | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 1120 | palkovsky | 1 | # |
| 2071 | jermar | 2 | # Copyright (c) 2001-2004 Jakub Jermar |
| 1120 | palkovsky | 3 | # All rights reserved. |
| 4 | # |
||
| 5 | # Redistribution and use in source and binary forms, with or without |
||
| 6 | # modification, are permitted provided that the following conditions |
||
| 7 | # are met: |
||
| 8 | # |
||
| 9 | # - Redistributions of source code must retain the above copyright |
||
| 10 | # notice, this list of conditions and the following disclaimer. |
||
| 11 | # - Redistributions in binary form must reproduce the above copyright |
||
| 12 | # notice, this list of conditions and the following disclaimer in the |
||
| 13 | # documentation and/or other materials provided with the distribution. |
||
| 14 | # - The name of the author may not be used to endorse or promote products |
||
| 15 | # derived from this software without specific prior written permission. |
||
| 16 | # |
||
| 17 | # THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
||
| 18 | # IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
||
| 19 | # OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
||
| 20 | # IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
||
| 21 | # INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
||
| 22 | # NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
||
| 23 | # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
||
| 24 | # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
||
| 25 | # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
||
| 26 | # THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
||
| 27 | # |
||
| 28 | |||
| 29 | .text |
||
| 30 | |||
| 31 | .global context_save |
||
| 32 | .global context_restore |
||
| 33 | |||
| 34 | |||
| 35 | ## Save current CPU context |
||
| 36 | # |
||
| 37 | # Save CPU context to the context_t variable |
||
| 38 | # pointed by the 1st argument. Returns 1 in EAX. |
||
| 39 | # |
||
| 40 | context_save: |
||
| 41 | movl 0(%esp),%eax # the caller's return %eip |
||
| 42 | movl 4(%esp),%edx # address of the kernel_context variable to save context to |
||
| 43 | |||
| 44 | movl %esp,0(%edx) # %esp -> ctx->sp |
||
| 45 | movl %eax,4(%edx) # %eip -> ctx->pc |
||
| 46 | movl %ebx,8(%edx) # %ebx -> ctx->ebx |
||
| 47 | movl %esi,12(%edx) # %esi -> ctx->esi |
||
| 48 | movl %edi,16(%edx) # %edi -> ctx->edi |
||
| 49 | movl %ebp,20(%edx) # %ebp -> ctx->ebp |
||
| 50 | |||
| 51 | # Save TLS |
||
| 52 | movl %gs:0, %eax |
||
| 53 | movl %eax, 24(%edx) # tls -> ctx->tls |
||
| 54 | |||
| 55 | xorl %eax,%eax # context_save returns 1 |
||
| 56 | incl %eax |
||
| 57 | ret |
||
| 58 | |||
| 59 | |||
| 60 | ## Restore saved CPU context |
||
| 61 | # |
||
| 62 | # Restore CPU context from context_t variable |
||
| 63 | # pointed by the 1st argument. Returns 0 in EAX. |
||
| 64 | # |
||
| 65 | context_restore: |
||
| 66 | movl 4(%esp),%eax # address of the kernel_context variable to restore context from |
||
| 67 | movl 0(%eax),%esp # ctx->sp -> %esp |
||
| 68 | movl 4(%eax),%edx # ctx->pc -> %edx |
||
| 69 | movl 8(%eax),%ebx # ctx->ebx -> %ebx |
||
| 70 | movl 12(%eax),%esi # ctx->esi -> %esi |
||
| 71 | movl 16(%eax),%edi # ctx->edi -> %edi |
||
| 72 | movl 20(%eax),%ebp # ctx->ebp -> %ebp |
||
| 73 | |||
| 74 | movl %edx,0(%esp) # ctx->pc -> saver's return %eip |
||
| 1391 | palkovsky | 75 | |
| 1120 | palkovsky | 76 | # Set thread local storage |
| 1391 | palkovsky | 77 | pushl %edi |
| 1120 | palkovsky | 78 | movl 24(%eax), %eax # Set arg1 to TLS addr |
| 79 | movl $1, %edi # Syscall 1 |
||
| 80 | int $0x30 |
||
| 1391 | palkovsky | 81 | popl %edi |
| 1120 | palkovsky | 82 | |
| 83 | xorl %eax,%eax # context_restore returns 0 |
||
| 84 | ret |