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Line 34... Line 34...
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void exception(void)
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void exception(void)
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{
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{
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    int excno;
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    int excno;
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    __u32 epc;
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    __u32 epc;
- 
 
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    __u32 epc_shift = 0;
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    pri_t pri;
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    pri_t pri;
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    pri = cpu_priority_high();
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    pri = cpu_priority_high();
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    epc = cp0_epc_read();
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    epc = cp0_epc_read();
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    cp0_status_write(cp0_status_read() & ~ cp0_status_exl_exception_bit);
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    cp0_status_write(cp0_status_read() & ~ cp0_status_exl_exception_bit);
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    if (THREAD) {
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    if (THREAD) {
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        THREAD->saved_pri = pri;
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        THREAD->saved_pri = pri;
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        THREAD->saved_epc = epc;
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        THREAD->saved_epc = epc;
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    }
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    }
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    /* decode exception number and process the exception */
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    /* decode exception number and process the exception */
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    switch(excno = (cp0_cause_read()>>2)&0x1f) {
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    switch (excno = (cp0_cause_read() >> 2) & 0x1f) {
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        case EXC_Int: interrupt(); break;
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        case EXC_Int:
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            interrupt();
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            break;
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        case EXC_TLBL:
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        case EXC_TLBL:
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        case EXC_TLBS:
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        case EXC_TLBS: tlb_invalid(); break;
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            tlb_invalid();
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            break;
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        case EXC_Mod:
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            panic("unhandled TLB Modification Exception\n");
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            break;
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        case EXC_AdEL:
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            panic("unhandled Address Error Exception - load or instruction fetch\n");
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            break;
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        case EXC_AdES:
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            panic("unhandled Address Error Exception - store\n");
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            break;
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        case EXC_IBE:
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            panic("unhandled Bus Error Exception - fetch instruction\n");
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            break;
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        case EXC_DBE:
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            panic("unhandled Bus Error Exception - data reference: load or store\n");
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            break;
- 
 
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        case EXC_Bp:
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            /* it is necessary to not re-execute BREAK instruction after returning from Exception handler
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               (see page 138 in R4000 Manual for more information) */
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            epc_shift = 4;
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            break;
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        case EXC_RI:
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            panic("unhandled Reserved Instruction Exception\n");
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            break;
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        case EXC_CpU:
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            panic("unhandled Coprocessor Unusable Exception\n");
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            break;
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        case EXC_Ov:
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            panic("unhandled Arithmetic Overflow Exception\n");
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            break;
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        case EXC_Tr:
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            panic("unhandled Trap Exception\n");
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            break;
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        case EXC_VCEI:
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            panic("unhandled Virtual Coherency Exception - instruction\n");
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            break;
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        case EXC_FPE:
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            panic("unhandled Floating-Point Exception\n");
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            break;
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        case EXC_WATCH:
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            panic("unhandled reference to WatchHi/WatchLo address\n");
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            break;
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        case EXC_VCED:
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            panic("unhandled Virtual Coherency Exception - data\n");
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            break;
- 
 
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        default:
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        default: panic("unhandled exception %d\n", excno); break;
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            panic("unhandled exception %d\n", excno);
55 
    }
 105 
    }
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    if (THREAD) {
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    if (THREAD) {
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        pri = THREAD->saved_pri;
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        pri = THREAD->saved_pri;
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        epc = THREAD->saved_epc;
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        epc = THREAD->saved_epc;
60 
    }
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    }
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    cp0_epc_write(epc);
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    cp0_epc_write(epc + epc_shift);
63 
    cp0_status_write(cp0_status_read() | cp0_status_exl_exception_bit);
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    cp0_status_write(cp0_status_read() | cp0_status_exl_exception_bit);
64 
    cpu_priority_restore(pri);
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    cpu_priority_restore(pri);
65 
}
 115 
}