static void trap_dispatch(struct trapframe *tf)
{
int i;
int code = GET_CAUSE_EXCODE(tf->tf_cause);
switch (code) {
case EX_IRQ:
interrupt_handler(tf);
break;
case EX_MOD:
handle_tlbmiss(tf, 1, 1);
break;
case EX_TLBL:
handle_tlbmiss(tf, 0, 0);
break;
case EX_TLBS:
handle_tlbmiss(tf, 1, 0);
break;
case EX_RI: {
if(tf->tf_cause & (1 << 31)) {
print_trapframe(tf);
panic("Cannot fix unimplemented instruction in branch delay slot.");
}
const uint32_t DIV_OPCODE_MASK = 0xFC00FFFF;
const uint32_t DIV_OPCODE = 0x0000001A;
const uint32_t DIVU_OPCODE = 0x0000001B;
const uint32_t MULTU_OPCODE = 0x00000019;
uint32_t instruction = *(uint32_t*)tf->tf_epc;
if((instruction & DIV_OPCODE_MASK) == DIV_OPCODE) {
int rt = (instruction >> 16) & 0x1F;
int rs = (instruction >> 21) & 0x1F;
int dividend = rs == 0 ? 0 : tf->tf_regs.reg_r[rs - 1];
int division = rt == 0 ? 0 : tf->tf_regs.reg_r[rt - 1];
tf->tf_lo = __divsi3(dividend, division);
tf->tf_hi = __modsi3(dividend, division);
tf->tf_epc = (void*)((uint32_t)tf->tf_epc + 4);
break;
}
else if((instruction & DIV_OPCODE_MASK) == DIVU_OPCODE) {
int rt = (instruction >> 16) & 0x1F;
int rs = (instruction >> 21) & 0x1F;
int dividend = rs == 0 ? 0 : tf->tf_regs.reg_r[rs - 1];
int division = rt == 0 ? 0 : tf->tf_regs.reg_r[rt - 1];
tf->tf_lo = udivmodsi4(dividend, division, 0);
tf->tf_hi = udivmodsi4(dividend, division, 1);
tf->tf_epc = (void*)((uint32_t)tf->tf_epc + 4);
break;
}
static void
trap_dispatch(struct trapframe *tf) {
int code = GET_CAUSE_EXCODE(tf->tf_cause);
switch(code){
case EX_IRQ:
interrupt_handler(tf);
break;
case EX_TLBL:
handle_tlbmiss(tf, 0);
break;
case EX_TLBS:
handle_tlbmiss(tf, 1);
break;
case EX_RI:
print_trapframe(tf);
kprintf("inst not include, I will use software to implement\n");
tf->tf_epc += 4;
//panic("hey man! Do NOT use that insn!");
break;
case EX_SYS:
//print_trapframe(tf);
tf->tf_epc += 4;
syscall();
break;
/* alignment error or access kernel
* address space in user mode */
case EX_ADEL:
case EX_ADES:
if(trap_in_kernel(tf)){
print_trapframe(tf);
panic("Alignment Error");
}else{
print_trapframe(tf);
do_exit(-E_KILLED);
}
break;
default:
print_trapframe(tf);
panic("Unhandled Exception");
}
}
