[16] | 1 | /* |
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[121] | 2 | * hal_kentry.h - MIPS32 registers mnemonics |
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[16] | 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 | #ifndef _HAL_KENTRY_H_ |
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| 24 | #define _HAL_KENTRY_H_ |
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| 25 | |
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[406] | 26 | ////////////////////////////////////////////////////////////////////////////////////////// |
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| 27 | // This file defines the MIPS32 specific mnemonics to access the "uzone", that is |
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| 28 | // a fixed size array of 32 bits integers, used by the kentry function to save/restore |
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| 29 | // the MIPS32 CPU registers, at each exception / interruption / syscall. |
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| 30 | // It also defines several initial values for the SR register. |
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| 31 | // |
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| 32 | // This file is included in the hal_kentry.S, hal_syscall.c, hal_exception.c, |
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| 33 | // and hal_context.c files. |
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| 34 | ////////////////////////////////////////////////////////////////////////////////////////// |
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[121] | 35 | |
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[16] | 36 | |
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[406] | 37 | /**************************************************************************************** |
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| 38 | * This structure defines the cpu_uzone for TSAR MIPS32, as well as the |
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| 39 | * mnemonics used by the hal_kentry assembly code. |
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| 40 | ***************************************************************************************/ |
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| 41 | |
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| 42 | #define UZ_MODE 0 /* c2_mode */ |
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| 43 | #define UZ_AT 1 |
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| 44 | #define UZ_V0 2 |
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| 45 | #define UZ_V1 3 |
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| 46 | #define UZ_A0 4 |
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| 47 | #define UZ_A1 5 |
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| 48 | #define UZ_A2 6 |
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| 49 | #define UZ_A3 7 |
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| 50 | #define UZ_T0 8 |
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| 51 | #define UZ_T1 9 |
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| 52 | #define UZ_T2 10 |
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| 53 | #define UZ_T3 11 |
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| 54 | #define UZ_T4 12 |
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| 55 | #define UZ_T5 13 |
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| 56 | #define UZ_T6 14 |
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| 57 | #define UZ_T7 15 |
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| 58 | #define UZ_T8 16 |
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| 59 | #define UZ_T9 17 |
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| 60 | #define UZ_S0 18 |
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| 61 | #define UZ_S1 19 |
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| 62 | #define UZ_S2 20 |
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| 63 | #define UZ_S3 21 |
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| 64 | #define UZ_S4 22 |
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| 65 | #define UZ_S5 23 |
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| 66 | #define UZ_S6 24 |
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| 67 | #define UZ_S7 25 |
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| 68 | #define UZ_S8 26 |
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| 69 | #define UZ_GP 27 |
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| 70 | #define UZ_RA 28 |
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| 71 | #define UZ_EPC 29 /* c0_epc */ |
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| 72 | #define UZ_CR 30 /* c0_cr */ |
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| 73 | #define UZ_SP 31 |
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| 74 | #define UZ_SR 32 /* c0_sr */ |
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| 75 | #define UZ_LO 33 |
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| 76 | #define UZ_HI 34 |
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| 77 | |
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| 78 | #define UZ_REGS 35 |
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| 79 | |
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| 80 | /************************************************************************************* |
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| 81 | * The hal_kentry_enter() function is the unique kernel entry point in case of |
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| 82 | * exception, interrupt, or syscall for the TSAR_MIPS32 architecture. |
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| 83 | * |
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| 84 | * When we enter the kernel, we test the status register: |
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| 85 | * - If the core is in user mode, we desactivate the MMU, and we save |
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| 86 | * the core context in the uzone of the calling thread descriptor. |
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| 87 | * - If the core is already in kernel mode (in case of interrupt), |
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| 88 | * we save the context in the kernel stack. |
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| 89 | * - In both cases, we increment the cores_in_kernel variable, |
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| 90 | * and we call the relevant exception/interrupt/syscall handler |
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| 91 | * |
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| 92 | * When we exit the kernel after handler execution: |
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| 93 | * - we restore the core context from the uzone and return to user space, |
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| 94 | * calling the hal_kentry_eret() |
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| 95 | ************************************************************************************/ |
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| 96 | void hal_kentry_enter(); |
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| 97 | |
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| 98 | /************************************************************************************* |
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| 99 | * The hal_kentry_eret() function contains only the assembly "eret" instruction, |
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| 100 | * that and the EXL bit in the c0_sr register, and jump to the address |
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| 101 | * contained in the c0_epc register. |
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| 102 | * ************************************************************************************/ |
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| 103 | void hal_kentry_eret(); |
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| 104 | |
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[121] | 105 | #endif /* _HAL_KENTRY_H_ */ |
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