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First/assembly.c

567 lines
16 KiB
C
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#include "assembly.h"
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#define MAX_LABEL_SIZE 30
#define MAX_LABEL_SIZE_str "30"
// Max instruction width is 25 characters without the null char
//
// INSTRUCTIONS:
// BYTE 3 BYTE 2 BYTE 1 BYTE 0
// +===================================================+
// | | | | |
// +===================================================+
//
//
// Exception:
// The bytecode 0xFFFFFFFx is an invalid command
// where x is any nibble
//
//
// INSTRUCTION FORMAT 0:
// +===================================================+
// | OPCODE | 24 BIT IMMEDIATE ADDRESS |
// +===================================================+
//
// INSTRUCTION FORMAT 1:
// +===================================================+
// | OPCODE | SOURCE REG | DEST REG |
// +===================================================+
//
// INSTRUCTION FORMAT 2:
// +===================================================+
// | OPCODE | DEST REG | 16 BIT IMMEDIATE |
// +===================================================+
//
//
//
// OPCODE FORMAT:
// ______________________________________________________________________________________________________
// |BIT | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 |
// +----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
// | | INSTR. FORMAT | 8bit opcode num : 16bit opcode num |
// +----+-----------------+-----------------------------+-----------------------------------------------+
//
//
// INSTRUCTION FORMAT 0 OPCODE NUM:
// +-------+----------------------------------+--------------+
// | NUM | DESCRIPTION | AFFECT FLAGS |
// +-------+----------------------------------+--------------+
// | 5'h0 | NOP | NO |
// +-------+----------------------------------+--------------+
// | 5'h1 | Unconditional Jump | NO |
// +-------+----------------------------------+--------------+
// | 5'h2 | Jump if zero flag is set | NO |
// +-------+----------------------------------+--------------+
// | 5'h3 | Jump if zero flag is not set | NO |
// +-------+----------------------------------+--------------+
// | 5'h4 | Jump if carry flag is set | NO |
// +-------+----------------------------------+--------------+
// | 5'h5 | Jump if carry flag is not set | NO |
// +-------+----------------------------------+--------------+
// | 5'h10 | Unconditional ret | NO |
// +-------+----------------------------------+--------------+
// | 5'h11 | Unconditional call | NO |
// +-------+----------------------------------+--------------+
// | 5'h12 | Call if zero flag is set | NO |
// +-------+----------------------------------+--------------+
// | 5'h13 | Call if zero flag is not set | NO |
// +-------+----------------------------------+--------------+
// | 5'h14 | Call if carry flag is set | NO |
// +-------+----------------------------------+--------------+
// | 5'h15 | Call if carry flag is not set | NO |
//
//
// | | | |
// +-------+----------------------------------+--------------+
// | 5'h0F | MOV immediate to SP | |
// +-------+----------------------------------+--------------+
// | | | |
//
//
// INSTRUCTION FORMAT 1 OPCODE NUM:
// +-------+---------------------------------------------+--------------+------------+------------+
// | NUM | DESCRIPTION | AFFECT FLAGS | SOURCE REG | DEST REG |
// +-------+---------------------------------------------+--------------+------------+------------+
// | 13'h0 | ADD | YES | operand 1 | operand 1 |
// +-------+---------------------------------------------+--------------|------------+------------+
// | 13'h1 | SUBTRACT | YES | operand 1 | operand 1 |
// +-------+---------------------------------------------+--------------|------------+------------+
// | 13'h2 | SHIFT LEFT | YES | operand | |
// +-------+---------------------------------------------+--------------|------------+------------+
// | 13'h3 | SHIFT RIGHT | YES | operand | |
// +-------+---------------------------------------------+--------------|------------+------------+
// | 13'h4 | COMPARE (SUBTRACT WITHOUT SAVE) | YES | operand 1 | operand 1 |
// +-------+---------------------------------------------+--------------+------------+------------+
// | 13'h5 | HALT | NO | | |
// +-------+---------------------------------------------+--------------+------------+------------+
// | 13'h6 | PUSH | NO | operand | |
// +-------+---------------------------------------------+--------------+------------+------------+
// | 13'h7 | POP | NO | operand | |
// +-------+---------------------------------------------+--------------+------------+------------+
// | 13'h8 | MOV register to indirect register ( 32-bit )| NO | operand | (operand) |
// +-------+---------------------------------------------+--------------+------------+------------+
// | 13'h9 | MOV indirect register to register ( 32-bit )| NO | (operand) | operand |
//
//
// INSTRUCTION FORMAT 2 OPCODE NUM:
// +-------+----------------------------------------------+--------------+
// | NUM | DESCRIPTION | AFFECT FLAGS |
// +-------+----------------------------------------------+--------------+
// | 5'd0 | MOV IMMEDIATE TO DEST LOW PART OF REGISTER | NO |
// +-------+----------------------------------------------+--------------+
// | 5'd1 | MOV IMMEDIATE TO DEST HIGH PART OF REGISTER | NO |
#define MAX_INSTRUCTION_LENGTH 26
char *disassemble(uint32_t opcode_be){
uint32_t opcode=(opcode_be&0x000000FF)<<24|(opcode_be&0x0000FF00)<<8|(opcode_be&0x00FF0000)>>8|(opcode_be&0xFF000000)>>24;
char *ret=malloc(MAX_INSTRUCTION_LENGTH);
if (!ret)
return NULL;
//////// PARSE BITECODE //////////
int instruction_format,opcode_num;
uint32_t val;
uint8_t val1;
uint8_t val2;
instruction_format=(opcode&0xE0000000)>>29;
if(instruction_format==0){
// 8bit opcode
opcode_num=(opcode&0x1F000000)>>24;
val=opcode&0x00FFFFFF;
switch(opcode_num){
case 0x00:
snprintf(ret,MAX_INSTRUCTION_LENGTH,"NOP");
break;
case 0x10:
snprintf(ret,MAX_INSTRUCTION_LENGTH,"RET");
break;
case 0x01:
case 0x11:
snprintf(ret,MAX_INSTRUCTION_LENGTH,"%s $%06X",(opcode_num&0x10)?"CALL":"JMP",val);
break;
case 0x02:
case 0x03:
case 0x12:
case 0x13:
snprintf(ret,MAX_INSTRUCTION_LENGTH,"%s,%s $%06X",(opcode_num&0x10)?"CALL":"JMP",opcode_num&1?"NZ":"Z",val);
break;
case 0x04:
case 0x05:
case 0x14:
case 0x15:
snprintf(ret,MAX_INSTRUCTION_LENGTH,"%s,%s $%06X",(opcode_num&0x10)?"CALL":"JMP",opcode_num&1?"NC":"C",val);
break;
case 0x0F:
snprintf(ret,MAX_INSTRUCTION_LENGTH,"MOV $%06X,%%SP",val);
break;
default:
snprintf(ret,MAX_INSTRUCTION_LENGTH,"UNRECOGNISED INSTR");
break;
}
}else if(instruction_format==1){
// 16bit opcode
opcode_num=(opcode&0x1FFF0000)>>16;
val1=(opcode&0x0000FF00)>>8;
val2=opcode&0x000000FF;
switch(opcode_num){
case 0x00:
snprintf(ret,MAX_INSTRUCTION_LENGTH,"ADD %%R%0d, %%R%0d",val1,val2);
break;
case 0x01:
snprintf(ret,MAX_INSTRUCTION_LENGTH,"SUB %%R%0d, %%R%0d",val1,val2);
break;
case 0x02:
snprintf(ret,MAX_INSTRUCTION_LENGTH,"SL %%R%0d",val1);
break;
case 0x03:
snprintf(ret,MAX_INSTRUCTION_LENGTH,"SR %%R%0d",val1);
break;
case 0x04:
snprintf(ret,MAX_INSTRUCTION_LENGTH,"CMP %%R%0d, %%R%0d",val1,val2);
break;
case 0x05:
snprintf(ret,MAX_INSTRUCTION_LENGTH,"HALT");
break;
case 0x06:
snprintf(ret,MAX_INSTRUCTION_LENGTH,"PUSH %%R%0d",val1);
break;
case 0x07:
snprintf(ret,MAX_INSTRUCTION_LENGTH,"POP %%R%0d",val1);
break;
case 0x08:
snprintf(ret,MAX_INSTRUCTION_LENGTH,"MOV %%R%0d,(%%R%0d)",val1,val2);
break;
case 0x09:
snprintf(ret,MAX_INSTRUCTION_LENGTH,"MOV (%%R%0d),%%R%0d",val1,val2);
break;
default:
snprintf(ret,MAX_INSTRUCTION_LENGTH,"UNRECOGNISED INSTRUCTION");
break;
}
}else if(instruction_format==2){
// 16bit opcode
opcode_num=(opcode&0x1F000000)>>24;
val1=(opcode&0x00FF0000)>>16;
val=opcode&0x0000FFFF;
switch(opcode_num){
case 0x00:
snprintf(ret,MAX_INSTRUCTION_LENGTH,"MOV $%04X, %%R%0dl",val,val1);
break;
case 0x01:
snprintf(ret,MAX_INSTRUCTION_LENGTH,"MOV $%04X, %%R%0dh",val,val1);
break;
default:
snprintf(ret,MAX_INSTRUCTION_LENGTH,"UNRECOGNISED INSTRUCTION");
break;
}
}else
snprintf(ret,MAX_INSTRUCTION_LENGTH,"UNRECOGNISED INSTRUCTION");
return ret;
}
int64_t parse_immediate(char* str,struct assembler_context_t *assembler_context){
if(*str=='0'){
uint32_t addr;
if(sscanf(str,"0x%08X",&addr)!=1){
return -1;
}else
return addr;
}else{
// Get name size
int len=0;
for(int i=0;i<MAX_LABEL_SIZE+1;i++){
if(i==MAX_LABEL_SIZE)
return -2;
if(str[i]==0||str[i]=='\n'||str[i]==' '){
break;
}else
len++;
}
struct label_ll_t *search=assembler_context->label_ll;
while(search){
if(strncmp(str,search->name,len)==0)
return search->address;
search=search->next;
}
return -2;
}
}
int64_t assemble_line(char *line, struct assembler_context_t *assembler_context){
uint16_t opcode;
int x;
int call;
if( ((call=strncmp(line,"JMP ",4))==0) || (strncmp(line,"CALL ",5)==0) ){
if(call){
x=4;
opcode=0x10;
}else{
x=3;
opcode=0x00;
}
if(line[x]==' '){
opcode|=0x01;
}else if(line[x]==','){
x++;
if(line[x]=='Z'){
opcode|=0x02;
x++;
}else if(line[x]=='C'){
opcode|=0x04;
x++;
}else if(line[x]=='N'){
x++;
if(line[x]=='Z'){
opcode|=0x03;
x++;
}else if(line[x]=='C'){
opcode|=0x09;
x++;
}else
return -2;
}else
return -2;
}else
return -2;
while(line[x]==' ')x++;
if(line[x]=='$'){
x++;
int64_t imm=parse_immediate(line+x,assembler_context);
if(imm<0){
switch(imm){
default:
return -2;
case -2:
return -3;
}
}else
return opcode<<24|(imm&0x00FFFFFF);
}else
return -2;
}else{
uint8_t r1,r0,params;
if(strncmp(line,"ADD ",4)==0){
x=3;
opcode=0x2000;
params=2;
}else if(strncmp(line,"SUB ",4)==0){
x=3;
opcode=0x2001;
params=2;
}else if(strncmp(line,"SL ",3)==0){
x=2;
opcode=0x2002;
params=1;
}else if(strncmp(line,"SR ",3)==0){
x=2;
opcode=0x2003;
params=1;
}else if(strncmp(line,"CMP ",4)==0){
x=3;
opcode=0x2004;
params=2;
}else
params=0;
if(params!=0){
while(line[x]==' ')x++;
if(line[x]=='%'){
x++;
if(line[x]=='R'){
x++;
if(line[x]>='0'&&line[x]<='7'){
r0=line[x]-'0';
if(params==2){
x++;
while(line[x]==' ')x++;
if(line[x]==','){
x++;
while(line[x]==' ')x++;
if(line[x]=='%'){
x++;
if(line[x]=='R'){
x++;
if(line[x]>='0'&&line[x]<='7'){
r1=line[x]-'0';
return (opcode<<16)|r0<<8|r1;
}else
return -2;
}else
return -2;
}else
return -2;
}else
return -2;
}else
return (opcode<<16)|r0<<2;
}else
return -2;
}else
return -2;
}else
return -2;
}else if(strncmp(line,"MOV ",4)==0){
uint32_t data;
x=3;
while(line[x]==' ')x++;
if(line[x]=='$'){
x++;
if(sscanf(line+x,"%06X",&data)==1){
x+=4;
while(line[x]==' ')x++;
if(line[x]!=','){ //24 bit TODO: not the best way to parse this
x+=2;
while(line[x]==' ')x++;
}
if(line[x]==','){
x++;
while(line[x]==' ')x++;
if(line[x]=='%'){
x++;
if(line[x]=='R'){
x++;
if(line[x]>='0'&&line[x]<='7'){
r1=line[x]-'0';
x++;
if(line[x]=='l')
return 0x40000000|r1<<16|(data&0xFFFF);
else if(line[x]=='h')
return 0x41000000|r1<<16|(data&0xFFFF);
else
return -2;
}else
return -2;
}else if(line[x]=='S'){
x++;
if(line[x]=='P'){
return 0x0F000000|(data&0x00FFFFFF);
}else
return -2;
}else
return -2;
}else
return -2;
}else
return -2;
}else
return -2;
}else if(line[x]=='%'){
x++;
if(line[x]=='R'){
x++;
if(line[x]>='0'&&line[x]<='7'){
r0=line[x]-'0';
x++;
while(line[x]==' ')x++;
if(line[x]==','){
x++;
while(line[x]==' ')x++;
if(line[x]=='('){
x++;
while(line[x]==' ')x++;
if(line[x]=='%'){
x++;
if(line[x]=='R'){
x++;
if(line[x]>='0'&&line[x]<='7'){
r1=line[x]-'0';
x++;
while(line[x]==' ')x++;
if(line[x]==')'){
return 0x20080000|(r0&0xFF)<<8|(r1&0xFF);
}else
return -2;
}else
return -2;
}else
return -2;
}else
return -2;
}else
return -2;
}else
return -2;
}else
return -2;
}else
return -2;
}else
return -2;
}else if(strncmp(line,"HALT ",5)==0||strncmp(line,"HALT\0",5)==0){
x=4;
while(line[x]==' ')x++;
if(line[x]==0)
return 0x20050000;
else
return -2;
}else if(strncmp(line,"RET ",4)==0||strncmp(line,"RET\0",4)==0){
return 0x10000000;
}else if(*line==':'){
return -1;
}else if(strncmp(line,"PUSH ",5)==0){
x=4;
while(line[x]==' ')x++;
if(line[x]=='%'){
x++;
if(line[x]=='R'){
x++;
if(line[x]>='0'&&line[x]<='7')
return 0x20060000|(line[x]-'0')<<8;
else
return -2;
}
}else
return -2;
}else if(strncmp(line,"POP ",4)==0){
x=3;
while(line[x]==' ')x++;
if(line[x]=='%'){
x++;
if(line[x]=='R'){
x++;
if(line[x]>='0'&&line[x]<='7')
return 0x20070000|(line[x]-'0')<<8;
else
return -2 ;
}
}else
return -2;
}else if(strncmp(line,"DDW ",4)==0){
x=4;
while(line[x]==' ')x++;
if(line[x]=='$'){
x++;
int64_t imm=parse_immediate(line+x,assembler_context);
if(imm<0){
switch(imm){
default:
return -2;
case -2:
return -3;
}
}else
return imm;
}else
return -2;
}
return -2;//TODO: figure out which statemnt falls through to this
}
}
int assembler_context_process(char* line,struct assembler_context_t *assembler_context){
switch(line[0]){
case ':':
if(line[1]==0)
return 1;
else{
char* label=malloc(MAX_LABEL_SIZE+1);
sscanf(line+1,"%"MAX_LABEL_SIZE_str"s",label);
struct label_ll_t **current;
current=&(assembler_context->label_ll);
while(*current)
current=&((*current)->next);
*current=malloc(sizeof(struct label_ll_t));
(*current)->name=label;
(*current)->address=assembler_context->current_location;
(*current)->next=NULL;
}
break;
case 0:
return 0;
default:
assembler_context->current_location+=4;
}
return 0;
}
struct assembler_context_t *malloc_assembler_context(){
struct assembler_context_t *ret;
ret=malloc(sizeof(struct assembler_context_t));
ret->current_location=0x00000000;
ret->label_ll=NULL;
return ret;
}
void free_assembler_context(struct assembler_context_t *tofree){
struct label_ll_t *tofree_ll=tofree->label_ll;
while(tofree_ll){
struct label_ll_t *temp=tofree_ll;
tofree_ll=tofree_ll->next;
free(temp->name);
free(temp);
}
free(tofree);
}
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