emulator/src/toy.c

94 lines
2.2 KiB
C

#include "toy.h"
//gibt Anzahl der erfolgreich gelesenen Maschinenworte zurück(-1 im Fehlerfall).
int initialise_ram(uint16_t *ram, int argc, char **argv )
{
//open Input Stream
FILE *fp;
int j=0;
char tempS[CPU_WORD_SIZE+1]; //+1 for "\0"
for(int i=0;i<RAM_SIZE;i++) ram[i]=0;
if(argc<2)
{
fprintf(stderr,"%s","no \".toy\" input file!\n");
return -1;
}
if(argc >2)
{
fprintf(stderr,"%s","too many input files!\n");
return -1;
}
if(!(fp=fopen(argv[1],"rb")))
{
fprintf(stderr,"%s","open input stream fault !\n");
return -1;
}
// initialise Toy-RAM
do
{
for(int i=0;i<=CPU_WORD_SIZE;i++)
{
tempS[i]=fgetc(fp);
if(tempS[0]==EOF) break;
if(tempS[i]!='1' && tempS[i]!='0' && i<CPU_WORD_SIZE)
{
fprintf(stderr,"%s","input file corrupted\n");
return -1;
}
}
tempS[CPU_WORD_SIZE]='\0';
ram[j]=strtoul(tempS,NULL,2);
j++;
}while(tempS[0]!=EOF);
fclose(fp);
return j-1;
}
uint8_t get_opcode(uint16_t instruction)
{
uint8_t opcode;
opcode = instruction>>12;
return opcode;
}
int find_data(uint16_t instruction)
{
int instr;
if(instruction > 32767) instr = -1;
else instr=instruction & 4095;
return instr;
}
bool execute(uint8_t op_code, int data_addr, uint16_t *ram) // jump when 1
{
//vorsicht uint16 und Zweierkomplement noch nicht stringent !!!
//Vorsicht bool ops bei sigend int typs sind undefiniert !
static uint16_t accu;
switch(op_code)
{
case 0: ram[data_addr]=accu; break;
case 1: accu=ram[data_addr]; break;
// case 2: if(!accu) break;
case 3: accu=accu + ram[data_addr]; break;
case 4: accu=accu - ram[data_addr]; break;
case 5: accu=accu | ram[data_addr]; break;
case 6: accu=accu & ram[data_addr]; break;
case 7: accu=accu & ram[data_addr]; break;
case 8: break;
case 9: break;
case 10: break;
case 11: break;
case 12: break;
case 13: break;
case 14: break;
case 15: break;
}