| 1 | /* |
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| 2 | * __cpu-context.S - low-level context operations |
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| 3 | * |
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| 4 | * Copyright (c) 2008,2009,2010,2011,2012 Ghassan Almaless |
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| 5 | * Copyright (c) 2011,2012 UPMC Sorbonne Universites |
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| 6 | * |
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| 7 | * This file is part of ALMOS-kernel. |
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| 8 | * |
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| 9 | * ALMOS-kernel is free software; you can redistribute it and/or modify it |
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| 10 | * under the terms of the GNU General Public License as published by |
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| 11 | * the Free Software Foundation; version 2.0 of the License. |
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| 12 | * |
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| 13 | * ALMOS-kernel is distributed in the hope that it will be useful, but |
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| 14 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 16 | * General Public License for more details. |
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| 17 | * |
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| 18 | * You should have received a copy of the GNU General Public License |
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| 19 | * along with ALMOS-kernel; if not, write to the Free Software Foundation, |
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| 20 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
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| 21 | */ |
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| 22 | |
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| 23 | #define KSP 10*4 |
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| 24 | #define TID 9*4 |
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| 25 | #define TSS 8*4 |
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| 26 | #define LOADABLE 7*4 |
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| 27 | #define CR3 6*4 |
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| 28 | #define EIP 5*4 |
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| 29 | #define ESI 4*4 |
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| 30 | #define EDI 3*4 |
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| 31 | #define EBP 2*4 |
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| 32 | #define ESP 1*4 |
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| 33 | #define EBX 0*4 |
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| 34 | |
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| 35 | #define ESP_R0 1*4 |
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| 36 | #define ESP_R1 3*4 |
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| 37 | |
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| 38 | .text |
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| 39 | .global cpu_context_save |
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| 40 | cpu_context_save: |
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| 41 | movl 0(%esp), %edx /* Return Address */ |
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| 42 | movl 4(%esp), %ecx /* ctx pointer */ |
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| 43 | movl %ebx, (EBX)(%ecx) |
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| 44 | movl %esp, (ESP)(%ecx) |
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| 45 | movl %ebp, (EBP)(%ecx) |
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| 46 | movl %edi, (EDI)(%ecx) |
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| 47 | movl %esi, (ESI)(%ecx) |
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| 48 | movl %edx, (EIP)(%ecx) |
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| 49 | /* movl %cr3, (CR3)(%ecx) */ |
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| 50 | movl $0x0, %eax |
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| 51 | ret |
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| 52 | |
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| 53 | .global cpu_context_restore |
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| 54 | .extern cpu_context_load |
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| 55 | cpu_context_restore: |
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| 56 | movl 4(%esp), %ecx /* ctx pointer */ |
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| 57 | movl (LOADABLE)(%ecx), %eax |
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| 58 | test $0x1, %eax |
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| 59 | jz restore |
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| 60 | movl $0x0, (LOADABLE)(%ecx) |
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| 61 | push %ecx |
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| 62 | call cpu_context_load |
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| 63 | restore: |
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| 64 | movl 8(%esp), %eax /* Return Value */ |
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| 65 | movl (TSS)(%ecx), %ebx |
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| 66 | movl (TID)(%ecx), %edx |
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| 67 | movl %edx, (ESP_R1)(%ebx) |
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| 68 | movl (KSP)(%ecx), %edx |
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| 69 | movl %edx, (ESP_R0)(%ebx) |
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| 70 | movl (EBX)(%ecx), %ebx |
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| 71 | movl (ESP)(%ecx), %esp |
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| 72 | movl (EBP)(%ecx), %ebp |
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| 73 | movl (EDI)(%ecx), %edi |
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| 74 | movl (ESI)(%ecx), %esi |
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| 75 | movl (EIP)(%ecx), %edx |
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| 76 | /* movl (CR3)(%ecx), %cr3 */ |
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| 77 | movl %edx, 0(%esp) |
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| 78 | ret |
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