426 lines
13 KiB
C
426 lines
13 KiB
C
#include "simdata.h"
|
|
#include "cpu.h"
|
|
#include <stdlib.h>
|
|
|
|
|
|
|
|
struct fetch_data_t *malloc_fetch_data(){
|
|
return NULL;
|
|
}
|
|
void free_fetch_data(__attribute__((unused)) struct fetch_data_t *tofree){
|
|
}
|
|
int fetch(struct simdata_t *simdata){
|
|
free_instr_list(&simdata->cpu_gui_hints->fetching_list);
|
|
simdata->decode_data->in_bytecode=(uint32_t)(simdata->RAM[simdata->registers->PC])<<24|(uint32_t)(simdata->RAM[simdata->registers->PC+1])<<16|(uint32_t)(simdata->RAM[simdata->registers->PC+2])<<8|(uint32_t)(simdata->RAM[simdata->registers->PC+3]);
|
|
simdata->decode_data->address=simdata->registers->PC;
|
|
add_to_instr_list(&simdata->cpu_gui_hints->fetching_list,simdata->registers->PC);
|
|
simdata->registers->PC+=4;
|
|
return 0;
|
|
}
|
|
|
|
|
|
|
|
|
|
struct decode_data_t *malloc_decode_data(){
|
|
return malloc(sizeof(struct decode_data_t));
|
|
}
|
|
void free_decode_data(struct decode_data_t *tofree){
|
|
free(tofree);
|
|
}
|
|
int decode(struct simdata_t *simdata){
|
|
uint16_t opcode,op1,op2,imm;
|
|
free_instr_list(&simdata->cpu_gui_hints->decoding_list);
|
|
switch((simdata->decode_data->in_bytecode&0xE0000000)>>29){
|
|
case 0:
|
|
opcode=(simdata->decode_data->in_bytecode&0x1F000000)>>24;
|
|
switch(opcode){
|
|
case 0x00:
|
|
simdata->exec_data->EXEC_ACTION=NOP;
|
|
break;
|
|
case 0x01:
|
|
case 0x02:
|
|
case 0x03:
|
|
case 0x04:
|
|
case 0x05:
|
|
case 0x11:
|
|
case 0x12:
|
|
case 0x13:
|
|
case 0x14:
|
|
case 0x15:
|
|
switch(opcode){
|
|
case 0x01: case 0x11: simdata->exec_data->COND=NONE; break;
|
|
case 0x02: case 0x12: simdata->exec_data->COND=ZERO; break;
|
|
case 0x03: case 0x13: simdata->exec_data->COND=NZERO; break;
|
|
case 0x04: case 0x14: simdata->exec_data->COND=CARRY; break;
|
|
case 0x05: case 0x15: simdata->exec_data->COND=NCARRY; break;
|
|
default: return 1;
|
|
}
|
|
simdata->exec_data->out_op->OP_ADDR=IMMEDIATE;
|
|
simdata->exec_data->out_op->data=simdata->decode_data->in_bytecode&0x00FFFFFF;
|
|
simdata->exec_data->EXEC_ACTION=(opcode&0x10)?CALL:JUMP;
|
|
break;
|
|
case 0x0F:
|
|
simdata->exec_data->EXEC_ACTION=MOVE;
|
|
simdata->exec_data->in_op1->OP_ADDR=IMMEDIATE;
|
|
simdata->exec_data->in_op1->data=simdata->decode_data->in_bytecode&0x00FFFFFF;
|
|
simdata->exec_data->out_op->OP_ADDR=REGISTER;
|
|
simdata->exec_data->out_op->data=0;
|
|
break;
|
|
case 0x10:
|
|
simdata->exec_data->EXEC_ACTION=RET;
|
|
break;
|
|
default:
|
|
return 1;
|
|
}
|
|
break;
|
|
case 1:
|
|
opcode=(simdata->decode_data->in_bytecode&0x1FFF0000)>>16;
|
|
op1=(simdata->decode_data->in_bytecode&0x0000FF00)>>8;
|
|
op2=(simdata->decode_data->in_bytecode&0x000000FF);
|
|
|
|
|
|
simdata->exec_data->in_op1->data=op1;
|
|
simdata->exec_data->in_op2->data=op2;
|
|
switch(opcode){
|
|
case 0x01:
|
|
case 0x02:
|
|
case 0x03:
|
|
case 0x04:
|
|
case 0x05:
|
|
case 0x06:
|
|
case 0x07:
|
|
simdata->exec_data->in_op1->OP_ADDR=REGISTER;
|
|
simdata->exec_data->in_op2->OP_ADDR=REGISTER;
|
|
break;
|
|
case 0x08:
|
|
simdata->exec_data->in_op1->OP_ADDR=REGISTER;
|
|
simdata->exec_data->in_op2->OP_ADDR=REGISTER_IND;
|
|
break;
|
|
case 0x09:
|
|
simdata->exec_data->in_op1->OP_ADDR=REGISTER_IND;
|
|
simdata->exec_data->in_op2->OP_ADDR=REGISTER;
|
|
break;
|
|
}
|
|
|
|
switch(opcode){
|
|
case 0x05:
|
|
simdata->exec_data->EXEC_ACTION=HALT;
|
|
break;
|
|
case 0x06:
|
|
simdata->exec_data->EXEC_ACTION=PUSH;
|
|
break;
|
|
case 0x07:
|
|
simdata->exec_data->EXEC_ACTION=POP;
|
|
break;
|
|
case 0x08:
|
|
case 0x09:
|
|
simdata->exec_data->EXEC_ACTION=MOVE;
|
|
break;
|
|
default:
|
|
simdata->exec_data->EXEC_ACTION=EXEC_ALU;
|
|
break;
|
|
}
|
|
|
|
switch(opcode){
|
|
case 0:
|
|
case 1:
|
|
case 4:
|
|
simdata->exec_data->out_op->OP_ADDR=REGISTER;
|
|
simdata->exec_data->out_op->data=op2;
|
|
break;
|
|
case 2:
|
|
case 3:
|
|
simdata->exec_data->out_op->OP_ADDR=REGISTER;
|
|
simdata->exec_data->out_op->data=op1;
|
|
break;
|
|
case 0x08:
|
|
simdata->exec_data->out_op->data=op2;
|
|
simdata->exec_data->out_op->OP_ADDR=REGISTER_IND;
|
|
break;
|
|
case 0x09:
|
|
simdata->exec_data->out_op->data=op2;
|
|
simdata->exec_data->out_op->OP_ADDR=REGISTER;
|
|
break;
|
|
}
|
|
|
|
|
|
switch(opcode){
|
|
case 0: simdata->exec_data->ALU_OP=ALU_ADD; break;
|
|
case 1: simdata->exec_data->ALU_OP=ALU_SUB; break;
|
|
case 2: simdata->exec_data->ALU_OP=ALU_SL; break;
|
|
case 3: simdata->exec_data->ALU_OP=ALU_SR; break;
|
|
case 4: simdata->exec_data->ALU_OP=ALU_CMP; break;
|
|
case 5:
|
|
case 6:
|
|
case 7:
|
|
case 8:
|
|
case 9:
|
|
break;
|
|
default:
|
|
return 1;
|
|
}
|
|
break;
|
|
case 2:
|
|
opcode=(simdata->decode_data->in_bytecode&0x1F000000)>>24;
|
|
op1=(simdata->decode_data->in_bytecode&0x00FF0000)>>16;
|
|
imm=(simdata->decode_data->in_bytecode&0x0000FFFF);
|
|
switch(opcode){
|
|
case 0:
|
|
simdata->exec_data->EXEC_ACTION=MOVE;
|
|
simdata->exec_data->in_op1->OP_ADDR=IMMEDIATE;
|
|
simdata->exec_data->in_op1->data=imm;
|
|
|
|
simdata->exec_data->out_op->OP_ADDR=REGISTERL;
|
|
simdata->exec_data->out_op->data=op1;
|
|
break;
|
|
case 1:
|
|
simdata->exec_data->EXEC_ACTION=MOVE;
|
|
simdata->exec_data->in_op1->OP_ADDR=IMMEDIATE;
|
|
simdata->exec_data->in_op1->data=imm;
|
|
|
|
simdata->exec_data->out_op->OP_ADDR=REGISTERH;
|
|
simdata->exec_data->out_op->data=op1;
|
|
break;
|
|
}
|
|
break;
|
|
default:
|
|
return 1;
|
|
}
|
|
simdata->exec_data->address=simdata->decode_data->address;
|
|
add_to_instr_list(&simdata->cpu_gui_hints->decoding_list,simdata->decode_data->address);
|
|
return 0;
|
|
}
|
|
|
|
|
|
|
|
|
|
struct exec_data_t *malloc_exec_data(){
|
|
struct exec_data_t *ret;
|
|
ret=malloc(sizeof(struct exec_data_t));
|
|
if(!ret)
|
|
return 0;
|
|
ret->in_op1=malloc(sizeof(struct exec_op_t));
|
|
if(!ret->in_op1){
|
|
free(ret);
|
|
return 0;
|
|
}
|
|
ret->in_op2=malloc(sizeof(struct exec_op_t));
|
|
if(!ret->in_op2){
|
|
free(ret->in_op1);
|
|
free(ret);
|
|
return 0;
|
|
}
|
|
ret->out_op=malloc(sizeof(struct exec_op_t));
|
|
if(!ret->out_op){
|
|
free(ret->in_op1);
|
|
free(ret->in_op2);
|
|
free(ret);
|
|
return 0;
|
|
}
|
|
return ret;
|
|
}
|
|
void free_exec_data(struct exec_data_t *tofree){
|
|
free(tofree->in_op1);
|
|
free(tofree->in_op2);
|
|
free(tofree->out_op);
|
|
free(tofree);
|
|
}
|
|
int exec(struct simdata_t *simdata){
|
|
free_instr_list(&simdata->cpu_gui_hints->executing_list);
|
|
switch(simdata->exec_data->EXEC_ACTION){
|
|
case CALL:
|
|
case JUMP:
|
|
int condition=0;
|
|
switch(simdata->exec_data->COND){
|
|
case NONE: condition=1; break;
|
|
case ZERO: condition=simdata->registers->FLAGS&1; break;
|
|
case NZERO: condition=!(simdata->registers->FLAGS&1); break;
|
|
case CARRY: condition=simdata->registers->FLAGS&2; break;
|
|
case NCARRY: condition=!(simdata->registers->FLAGS&2); break;
|
|
}
|
|
if(condition){
|
|
if(simdata->exec_data->EXEC_ACTION==CALL){
|
|
*(uint32_t*)(simdata->RAM+simdata->registers->SP)=simdata->registers->PC;
|
|
simdata->registers->SP+=4;
|
|
}
|
|
if(simdata->exec_data->out_op->OP_ADDR==IMMEDIATE)
|
|
simdata->registers->PC=(uint32_t)(simdata->exec_data->out_op->data);
|
|
else
|
|
return 1;
|
|
}
|
|
break;
|
|
case RET:
|
|
simdata->registers->SP-=4;
|
|
simdata->registers->PC=simdata->RAM[simdata->registers->SP];
|
|
break;
|
|
case EXEC_ALU:
|
|
if( simdata->exec_data->in_op1->OP_ADDR==REGISTER &&
|
|
simdata->exec_data->in_op2->OP_ADDR==REGISTER &&
|
|
simdata->exec_data->out_op->OP_ADDR==REGISTER ){
|
|
|
|
uint32_t result;
|
|
switch(simdata->exec_data->ALU_OP){
|
|
case ALU_ADD:
|
|
result = simdata->registers->GPR[simdata->exec_data->in_op1->data] +
|
|
simdata->registers->GPR[simdata->exec_data->in_op2->data];
|
|
simdata->registers->FLAGS=(simdata->registers->FLAGS&0xFFFFFFFD)|
|
|
(simdata->registers->GPR[simdata->exec_data->out_op->data] < simdata->registers->GPR[simdata->exec_data->in_op1->data])<<1;
|
|
break;
|
|
case ALU_SUB:
|
|
case ALU_CMP:
|
|
result = simdata->registers->GPR[simdata->exec_data->in_op1->data] -
|
|
simdata->registers->GPR[simdata->exec_data->in_op2->data];
|
|
simdata->registers->FLAGS=(simdata->registers->FLAGS&0xFFFFFFFD)|
|
|
(simdata->registers->GPR[simdata->exec_data->out_op->data] > simdata->registers->GPR[simdata->exec_data->in_op1->data])<<1;
|
|
break;
|
|
case ALU_SL:
|
|
simdata->registers->FLAGS=(simdata->registers->FLAGS&0xFFFFFFFD)|
|
|
((simdata->registers->GPR[simdata->exec_data->in_op1->data]&0x80000000)?2:0);
|
|
result = simdata->registers->GPR[simdata->exec_data->in_op1->data]<<1;
|
|
break;
|
|
case ALU_SR:
|
|
simdata->registers->FLAGS=(simdata->registers->FLAGS&0xFFFFFFFD)|
|
|
((simdata->registers->GPR[simdata->exec_data->in_op1->data]&0x00000001)?2:0);
|
|
result = simdata->registers->GPR[simdata->exec_data->in_op1->data]>>1;
|
|
break;
|
|
default:
|
|
return 1;
|
|
}
|
|
simdata->registers->FLAGS=(simdata->registers->FLAGS&0xFFFFFFFE)|(result==0);
|
|
if(simdata->exec_data->ALU_OP!=ALU_CMP)
|
|
simdata->registers->GPR[simdata->exec_data->out_op->data]=result;
|
|
}else
|
|
return 1;
|
|
break;
|
|
case MOVE:
|
|
switch(simdata->exec_data->out_op->OP_ADDR){
|
|
case REGISTERL:
|
|
if(simdata->exec_data->in_op1->OP_ADDR==IMMEDIATE)
|
|
simdata->registers->GPR[simdata->exec_data->out_op->data]=(simdata->registers->GPR[simdata->exec_data->out_op->data]&0xFFFF0000)|(0x0000FFFF&
|
|
simdata->exec_data->in_op1->data);
|
|
else
|
|
simdata->registers->GPR[simdata->exec_data->out_op->data]=(simdata->registers->GPR[simdata->exec_data->out_op->data]&0xFFFF0000)|(0x0000FFFF&
|
|
simdata->registers->GPR[simdata->exec_data->in_op1->data]);
|
|
break;
|
|
case REGISTERH:
|
|
if(simdata->exec_data->in_op1->OP_ADDR==IMMEDIATE)
|
|
simdata->registers->GPR[simdata->exec_data->out_op->data]=(simdata->registers->GPR[simdata->exec_data->out_op->data]&0x0000FFFF)|((0x0000FFFF&
|
|
simdata->exec_data->in_op1->data)<<16);
|
|
else
|
|
simdata->registers->GPR[simdata->exec_data->out_op->data]=(simdata->registers->GPR[simdata->exec_data->out_op->data]&0x0000FFFF)|((0x0000FFFF&
|
|
simdata->registers->GPR[simdata->exec_data->in_op1->data])<<16);
|
|
break;
|
|
case REGISTER: /* This is for special registers like the SP which is 24bits long */
|
|
if(simdata->exec_data->in_op1->OP_ADDR==IMMEDIATE){
|
|
if( (simdata->exec_data->in_op1->data&0xFF000000) == 0 )
|
|
simdata->registers->SP=simdata->exec_data->in_op1->data;
|
|
else
|
|
return 2;
|
|
}else{
|
|
if( (simdata->registers->GPR[simdata->exec_data->in_op1->data]&0xFF000000) == 0 )
|
|
simdata->registers->SP=simdata->registers->GPR[simdata->exec_data->in_op1->data];
|
|
else
|
|
return 2;
|
|
}
|
|
break;
|
|
case REGISTER_IND:
|
|
if(simdata->exec_data->in_op1->OP_ADDR==REGISTER){
|
|
*(uint32_t*)(simdata->RAM+(simdata->registers->GPR[simdata->exec_data->out_op->data]&0x00FFFFFF))=simdata->registers->GPR[simdata->exec_data->in_op1->data];
|
|
if(simdata->registers->GPR[simdata->exec_data->out_op->data]==0x00FFFFFC)
|
|
if(terminal_output(simdata->registers->GPR[simdata->exec_data->in_op1->data],simdata))
|
|
return 1;
|
|
}else
|
|
return 1;
|
|
break;
|
|
default:
|
|
return 1;
|
|
}
|
|
case NOP: break;
|
|
case HALT:
|
|
simdata->cpu_state=CPU_HALTED;
|
|
break;
|
|
case PUSH:
|
|
simdata->RAM[simdata->registers->SP ]=simdata->registers->GPR[simdata->exec_data->in_op1->data]&0x000000FF;
|
|
simdata->RAM[simdata->registers->SP+1]=(simdata->registers->GPR[simdata->exec_data->in_op1->data]&0x0000FF00)>>8;
|
|
simdata->RAM[simdata->registers->SP+2]=(simdata->registers->GPR[simdata->exec_data->in_op1->data]&0x00FF0000)>>16;
|
|
simdata->registers->SP+=4;
|
|
break;
|
|
case POP:
|
|
simdata->registers->SP-=4;
|
|
simdata->registers->GPR[simdata->exec_data->in_op1->data]=simdata->RAM[simdata->registers->SP];
|
|
simdata->registers->GPR[simdata->exec_data->in_op1->data]|=simdata->RAM[simdata->registers->SP+1]<<8;
|
|
simdata->registers->GPR[simdata->exec_data->in_op1->data]|=simdata->RAM[simdata->registers->SP+2]<<16;
|
|
break;
|
|
}
|
|
add_to_instr_list(&simdata->cpu_gui_hints->executing_list,simdata->exec_data->address);
|
|
return 0;
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
int state=0;
|
|
|
|
|
|
/*
|
|
* RETURN CODES:
|
|
* 0 : success
|
|
* 1 : error in execution stage
|
|
* 2 : error in decode stage
|
|
* 3 : error in fetch stage
|
|
* 4 : internal error
|
|
*/
|
|
int cpu_cycle_clock(struct simdata_t *simdata){
|
|
free_instr_list(&simdata->cpu_gui_hints->fetching_list);
|
|
free_instr_list(&simdata->cpu_gui_hints->decoding_list);
|
|
free_instr_list(&simdata->cpu_gui_hints->executing_list);
|
|
switch(state){
|
|
case 0:
|
|
switch(fetch(simdata)){
|
|
case 0: break;
|
|
default: return 3;
|
|
}
|
|
break;
|
|
case 1:
|
|
switch(decode(simdata)){
|
|
case 0: break;
|
|
default: return 2;
|
|
}
|
|
break;
|
|
case 2:
|
|
switch(exec(simdata)){
|
|
case 0: break;
|
|
case 2: return 4;
|
|
default: return 1;
|
|
}
|
|
break;
|
|
}
|
|
if(state==2)
|
|
state=0;
|
|
else
|
|
state++;
|
|
return 0;
|
|
}
|
|
|
|
|
|
int cpu_simdata_malloc(struct simdata_t *simdata){
|
|
simdata->fetch_data=malloc_fetch_data();
|
|
simdata->decode_data=malloc_decode_data();
|
|
simdata->exec_data=malloc_exec_data();
|
|
simdata->registers=malloc(sizeof(struct registers_t));
|
|
simdata->registers->PC=0x00000000;
|
|
simdata->registers->SP&=0x00FFFFFF; //intentionally leave it uninitialised but within the legal range
|
|
if((simdata->fetch_data!=NULL)&&(simdata->decode_data!=NULL)&&(simdata->exec_data!=NULL))
|
|
return 1;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
void cpu_simdata_free(struct simdata_t *simdata){
|
|
free_fetch_data(simdata->fetch_data);
|
|
free_decode_data(simdata->decode_data);
|
|
free_exec_data(simdata->exec_data);
|
|
free(simdata->registers);
|
|
}
|