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| Rev | Author | Line No. | Line |
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| 1 | jermar | 1 | # |
| 2 | # Copyright (C) 2001-2004 Jakub Jermar |
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| 3 | # All rights reserved. |
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| 4 | # |
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| 5 | # Redistribution and use in source and binary forms, with or without |
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| 6 | # modification, are permitted provided that the following conditions |
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| 7 | # are met: |
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| 8 | # |
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| 9 | # - Redistributions of source code must retain the above copyright |
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| 10 | # notice, this list of conditions and the following disclaimer. |
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| 11 | # - Redistributions in binary form must reproduce the above copyright |
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| 12 | # notice, this list of conditions and the following disclaimer in the |
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| 13 | # documentation and/or other materials provided with the distribution. |
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| 14 | # - The name of the author may not be used to endorse or promote products |
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| 15 | # derived from this software without specific prior written permission. |
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| 16 | # |
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| 17 | # THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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| 18 | # IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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| 19 | # OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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| 20 | # IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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| 21 | # INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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| 22 | # NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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| 23 | # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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| 24 | # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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| 25 | # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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| 26 | # THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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| 27 | # |
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| 28 | |||
| 29 | .text |
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| 30 | |||
| 414 | jermar | 31 | .global context_save_arch |
| 32 | .global context_restore_arch |
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| 1 | jermar | 33 | |
| 65 | decky | 34 | |
| 35 | ## Save current CPU context |
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| 1 | jermar | 36 | # |
| 414 | jermar | 37 | # Save CPU context to the context_t variable |
| 65 | decky | 38 | # pointed by the 1st argument. Returns 1 in EAX. |
| 39 | # |
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| 414 | jermar | 40 | context_save_arch: |
| 312 | jermar | 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 |
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| 1 | jermar | 43 | |
| 312 | jermar | 44 | movl %esp,0(%edx) # %esp -> ctx->sp |
| 45 | movl %eax,4(%edx) # %eip -> ctx->pc |
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| 46 | movl %ebx,8(%edx) # %ebx -> ctx->ebx |
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| 47 | movl %esi,12(%edx) # %esi -> ctx->esi |
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| 48 | movl %edi,16(%edx) # %edi -> ctx->edi |
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| 49 | movl %ebp,20(%edx) # %ebp -> ctx->ebp |
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| 1 | jermar | 50 | |
| 51 | xorl %eax,%eax # context_save returns 1 |
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| 52 | incl %eax |
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| 53 | ret |
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| 65 | decky | 54 | |
| 55 | |||
| 414 | jermar | 56 | ## Restore saved CPU context |
| 1 | jermar | 57 | # |
| 414 | jermar | 58 | # Restore CPU context from context_t variable |
| 65 | decky | 59 | # pointed by the 1st argument. Returns 0 in EAX. |
| 125 | jermar | 60 | # |
| 414 | jermar | 61 | context_restore_arch: |
| 1 | jermar | 62 | movl 4(%esp),%eax # address of the kernel_context variable to restore context from |
| 312 | jermar | 63 | movl 0(%eax),%esp # ctx->sp -> %esp |
| 64 | movl 4(%eax),%edx # ctx->pc -> %edx |
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| 65 | movl 8(%eax),%ebx # ctx->ebx -> %ebx |
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| 66 | movl 12(%eax),%esi # ctx->esi -> %esi |
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| 67 | movl 16(%eax),%edi # ctx->edi -> %edi |
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| 68 | movl 20(%eax),%ebp # ctx->ebp -> %ebp |
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| 1 | jermar | 69 | |
| 312 | jermar | 70 | movl %edx,0(%esp) # ctx->pc -> saver's return %eip |
| 125 | jermar | 71 | xorl %eax,%eax # context_restore returns 0 |
| 1 | jermar | 72 | ret |