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| Rev | Author | Line No. | Line |
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| 2362 | jancik | 1 | /* |
| 2 | * Copyright (c) 2007 Petr Stepan, Pavel Jancik |
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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 | /** @addtogroup arm32 |
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| 30 | * @{ |
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| 31 | */ |
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| 32 | /** @file |
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| 2413 | kebrt | 33 | * @brief Userspace switch. |
| 2362 | jancik | 34 | */ |
| 35 | |||
| 36 | #include <userspace.h> |
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| 37 | |||
| 2413 | kebrt | 38 | /** Struct for holding all general purpose registers. |
| 39 | * |
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| 40 | * Used to set registers when going to userspace. |
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| 41 | */ |
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| 2362 | jancik | 42 | typedef struct { |
| 43 | uint32_t r0; |
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| 44 | uint32_t r1; |
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| 45 | uint32_t r2; |
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| 46 | uint32_t r3; |
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| 47 | uint32_t r4; |
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| 48 | uint32_t r5; |
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| 49 | uint32_t r6; |
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| 50 | uint32_t r7; |
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| 51 | uint32_t r8; |
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| 52 | uint32_t r9; |
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| 53 | uint32_t r10; |
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| 54 | uint32_t r11; |
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| 55 | uint32_t r12; |
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| 56 | uint32_t sp; |
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| 57 | uint32_t lr; |
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| 58 | uint32_t pc; |
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| 59 | } ustate_t; |
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| 60 | |||
| 2464 | jermar | 61 | /** Changes processor mode and jumps to the address specified in the first |
| 62 | * parameter. |
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| 2362 | jancik | 63 | * |
| 64 | * @param kernel_uarg Userspace settings (entry point, stack, ...). |
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| 65 | */ |
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| 66 | void userspace(uspace_arg_t *kernel_uarg) |
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| 67 | { |
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| 68 | volatile ustate_t ustate; |
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| 69 | |||
| 2464 | jermar | 70 | /* set first parameter */ |
| 2362 | jancik | 71 | ustate.r0 = (uintptr_t) kernel_uarg->uspace_uarg; |
| 72 | |||
| 2464 | jermar | 73 | /* clear other registers */ |
| 74 | ustate.r1 = ustate.r2 = ustate.r3 = ustate.r4 = ustate.r5 = |
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| 75 | ustate.r6 = ustate.r7 = ustate.r8 = ustate.r9 = ustate.r10 = |
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| 76 | ustate.r11 = ustate.r12 = ustate.lr = 0; |
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| 2362 | jancik | 77 | |
| 2464 | jermar | 78 | /* set user stack */ |
| 2413 | kebrt | 79 | ustate.sp = ((uint32_t)kernel_uarg->uspace_stack) + PAGE_SIZE; |
| 2362 | jancik | 80 | |
| 2464 | jermar | 81 | /* set where uspace execution starts */ |
| 2362 | jancik | 82 | ustate.pc = (uintptr_t) kernel_uarg->uspace_entry; |
| 83 | |||
| 2464 | jermar | 84 | /* status register in user mode */ |
| 85 | ipl_t user_mode = current_status_reg_read() & |
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| 86 | (~STATUS_REG_MODE_MASK | USER_MODE); |
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| 2362 | jancik | 87 | |
| 2464 | jermar | 88 | /* set user mode, set registers, jump */ |
| 89 | asm volatile ( |
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| 90 | "mov r0, %0 \n" |
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| 91 | "msr spsr_c, %1 \n" |
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| 92 | "ldmfd r0!, {r0-r12, sp, lr}^ \n" |
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| 93 | "ldmfd r0!, {pc}^\n" |
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| 2413 | kebrt | 94 | : |
| 2464 | jermar | 95 | : "r" (&ustate), "r" (user_mode) |
| 2413 | kebrt | 96 | : "r0", "r1" |
| 2362 | jancik | 97 | ); |
| 98 | |||
| 2464 | jermar | 99 | /* unreachable */ |
| 100 | while(1) |
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| 101 | ; |
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| 2362 | jancik | 102 | } |
| 103 | |||
| 104 | /** @} |
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| 105 | */ |