| 1 | /** |
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| 2 | * File : reset.S |
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| 3 | * Author : Cesar FUGUET <cesar.fuguet-tortolero@lip6.fr> |
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| 4 | * Date : 16 October 2014 |
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| 5 | */ |
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| 6 | |
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| 7 | #include "hard_config.h" |
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| 8 | #include "cpu_registers.h" |
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| 9 | |
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| 10 | .section .reset,"ax",@progbits |
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| 11 | |
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| 12 | .extern seg_stack_base |
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| 13 | .extern seg_kcode_base |
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| 14 | .extern main |
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| 15 | |
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| 16 | .globl reset |
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| 17 | .ent reset |
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| 18 | .align 2 |
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| 19 | |
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| 20 | #define P_MASK ((1<<P_WIDTH)-1) |
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| 21 | #define Y_MASK ((1<<Y_WIDTH)-1) |
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| 22 | |
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| 23 | reset: |
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| 24 | .set noreorder |
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| 25 | |
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| 26 | /* |
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| 27 | * SR register initialization |
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| 28 | * - Disable interrupts |
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| 29 | * - Keep the Bootstrap Exception Vector (BEV) bit set |
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| 30 | */ |
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| 31 | li k0, 0x00400000 |
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| 32 | mtc0 k0, CP0_STATUS |
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| 33 | |
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| 34 | /* |
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| 35 | * All processors compute: |
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| 36 | * cid = (x * Y_SIZE) + y |
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| 37 | * pid = (cid * NB_PROCS_MAX) + lpid |
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| 38 | */ |
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| 39 | mfc0 k0, CP0_PROCID |
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| 40 | andi k0, k0, 0xFFF /* k0 <= proc_xyl */ |
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| 41 | andi t1, k0, P_MASK /* t1 <= lpid */ |
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| 42 | srl t2, k0, P_WIDTH /* t2 <= cluster_xy */ |
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| 43 | srl t3, t2, Y_WIDTH /* t3 <= x coordinate */ |
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| 44 | andi t4, t2, Y_MASK /* t4 <= y coordinate */ |
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| 45 | |
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| 46 | li t6, Y_SIZE /* t6 <= Y_SIZE */ |
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| 47 | multu t3, t6 |
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| 48 | mflo t5 |
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| 49 | addu k0, t5, t4 /* k0 <= cid */ |
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| 50 | |
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| 51 | li t7, NB_PROCS_MAX |
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| 52 | multu t5, t7 |
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| 53 | mflo t0 |
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| 54 | addu k1, t0, t1 /* k1 <= pid */ |
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| 55 | |
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| 56 | /* each proc initializes stack pointer (16K per processor) */ |
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| 57 | addi t0, k1, 1 /* t0 <= (pid + 1) */ |
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| 58 | sll t0, t0, 14 /* t0 <= (pid + 1) * 16K */ |
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| 59 | la sp, _stack |
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| 60 | addu sp, sp, t0 /* sp <= _stack[pid] */ |
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| 61 | |
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| 62 | /* jumps to main in kernel mode */ |
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| 63 | jal main |
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| 64 | nop |
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| 65 | |
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| 66 | j exit |
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| 67 | nop |
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| 68 | |
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| 69 | .set reorder |
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| 70 | .end reset |
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| 71 | |
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| 72 | |
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| 73 | |
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| 74 | .org 0x380 |
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| 75 | |
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| 76 | reset_exception_handler: |
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| 77 | mtc2 $0, MMU_DATA_PADDR_EXT |
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| 78 | j exception_handler |
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| 79 | |
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| 80 | |
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| 81 | |
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| 82 | .section .data |
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| 83 | |
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| 84 | /* |
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| 85 | * Stack segment definition |
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| 86 | * It contains the stacks of all processors, thus, if each one is using a |
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| 87 | * 16 Kbytes stack and the segment is 512 Kbytes length then the max number |
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| 88 | * of processors supported is 32 |
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| 89 | */ |
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| 90 | _stack: |
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| 91 | .space (1<<19) /* 512 Kbytes */ |
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| 92 | |
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| 93 | /* |
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| 94 | * vim: tabstop=4 : softtabstop=4 : shiftwidth=4 : expandtab |
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| 95 | */ |
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