// **************************************************************************
// **************************************************************************
// dvm <sa> <ea> - dump lc3 virtual memory
void dumpVMemory(char *s, int sa, int ea)
{
int i, ma;
printf("\n%s", s);
for (ma = sa; ma < ea;)
{
printf("\n0x%04x:", ma);
for (i=0; i<8; i++)
{
printf(" %04x", getMemoryData(ma+i));
}
ma+=8;
}
return;
} // end dumpVMemory
// ***********************************************************************
// ***********************************************************************
// lc3 simulator task
//
// argc = 2
// argv[0] = 0 - load from system
// 1 - load from FAT
//
int lc3Task(int argc, char* argv[])
{
int DR, oldpc, ir; // local variables
int i;
int LC3_REGS[8]; // General purpose registers
int LC3_CC = 0x02; // NZP condition codes
int LC3_PC = 0x3000; // program counter
int ips = 0; // instructions per swap
// Initialize LC3 Simulator
// clear registers
for (i=0; i<8; i++) LC3_REGS[i] = 0;
// set condition codes to nZp
LC3_CC = 0x02;
// load program
if ((LC3_PC = loadLC3Program(argv)) < 0) return -1;
// Execute LC3 program
while(1)
{
oldpc = LC3_PC; // save old pc for debug message
ir = getMemoryData(LC3_PC); // load ir and increment pc
LC3_PC = LC3_PC + 1; // increment program counter
DR = GET_DR; // preload destination register #
switch(GET_OPCODE)
{
case LC3_ADD: // ADD instruction
if (!GET_IMMEDIATE_BIT)
{ if (LC3_DEBUG&0x01) printf(ADD_MSG, oldpc, DR, GET_SR1, GET_SR2);
LC3_REGS[DR] = MASKTO16BITS(LC3_REGS[GET_SR1] + LC3_REGS[GET_SR2]);
}
else
{ if (LC3_DEBUG&0x01) printf(ADDI_MSG, oldpc, DR, GET_SR1, MASKTO16BITS(SEXT5(ir)));
LC3_REGS[DR] = MASKTO16BITS(LC3_REGS[GET_SR1] + SEXT5(ir));
}
SET_CC(LC3_REGS[DR]);
break;
case LC3_AND: // AND instruction
if (!GET_IMMEDIATE_BIT)
{ if (LC3_DEBUG&0x01) printf(AND_MSG, oldpc, DR, GET_SR1, GET_SR2);
LC3_REGS[DR] = MASKTO16BITS(LC3_REGS[GET_SR1] & LC3_REGS[GET_SR2]);
}
else
{ if (LC3_DEBUG&0x01) printf(ANDI_MSG, oldpc, DR, GET_SR1, MASKTO16BITS(SEXT5(ir)));
LC3_REGS[DR] = MASKTO16BITS(LC3_REGS[GET_SR1] & SEXT5(ir));
}
SET_CC(LC3_REGS[DR]);
break;
case LC3_BR: // BR instruction
if (ir == 0)
{ printf("\n**(%d) Illegal instruction 0x%04x at 0x%04x (frame %d)", LC3_TID, ir, LC3_PC, LC3_PC>>6);
return -1; // abort!
}
if ((LC3_CC&0x04 && GET_N) || (LC3_CC&0x02 && GET_Z) || (LC3_CC&0x01 && GET_P))
LC3_PC = LC3_PC + SEXT9(ir);
if (LC3_DEBUG&0x01)
{ char cchr[4];
cchr[0] = 0;
if (GET_N) strcat(cchr, "N");
if (GET_Z) strcat(cchr, "Z");
if (GET_P) strcat(cchr, "P");
printf(BR_MSG, oldpc, cchr, LC3_PC);
}
break;
case LC3_JMP: // JMP instruction
if (LC3_DEBUG&0x01)
{ if (GET_BASER == 7) printf(RET_MSG, oldpc);
else printf(JMP_MSG, oldpc, GET_BASER);
}
LC3_PC = LC3_REGS[GET_BASER];
break;
case LC3_JSR: // JSR instruction
LC3_REGS[7] = MASKTO16BITS(LC3_PC);
if (GET_ADDR_BIT == 0)
{ if (LC3_DEBUG&0x01) printf(JSRR_MSG, oldpc, GET_BASER);
LC3_PC = LC3_REGS[GET_BASER];
}
else
{ if (LC3_DEBUG&0x01) printf(JSR_MSG, oldpc, LC3_PC + SEXT11(ir));
LC3_PC = LC3_PC + SEXT11(ir);
}
break;
case LC3_LD: // LD instruction
if (LC3_DEBUG&0x01) printf(LD_MSG, oldpc, DR, SEXT9(ir));
LC3_REGS[DR] = MASKTO16BITS(getMemoryData(LC3_PC + SEXT9(ir)));
SET_CC(LC3_REGS[DR]);
break;
case LC3_LDI: // LDI instruction
if (LC3_DEBUG&0x01) printf(LDI_MSG, oldpc, DR, SEXT9(ir));
LC3_REGS[DR] = MASKTO16BITS(getMemoryData(getMemoryData(LC3_PC + SEXT9(ir))));
SET_CC(LC3_REGS[DR]);
break;
case LC3_LDR: // LDR instruction
if (LC3_DEBUG&0x01) printf(LDR_MSG, oldpc, DR, GET_BASER, SEXT6(ir));
LC3_REGS[DR] = MASKTO16BITS(getMemoryData(LC3_REGS[GET_BASER] + SEXT6(ir)));
SET_CC(LC3_REGS[DR]);
break;
case LC3_LEA: // LEA instruction
if (LC3_DEBUG&0x01) printf(LEA_MSG, oldpc, DR, LC3_PC + SEXT9(ir));
LC3_REGS[DR] = MASKTO16BITS(LC3_PC + SEXT9(ir));
SET_CC(LC3_REGS[DR]);
break;
case LC3_NOT: // NOT instruction
if (LC3_DEBUG&0x01) printf(NOT_MSG, oldpc, DR, GET_SR1);
LC3_REGS[DR] = MASKTO16BITS(~LC3_REGS[GET_SR1]);
SET_CC(LC3_REGS[DR]);
break;
case LC3_ST: // ST instruction
if (LC3_DEBUG&0x01) printf(ST_MSG, oldpc, GET_SR, LC3_PC + SEXT9(ir));
setMemoryData(LC3_PC + SEXT9(ir), LC3_REGS[GET_SR]);
break;
case LC3_STI: // STI instruction
if (LC3_DEBUG&0x01) printf(STI_MSG, oldpc, GET_SR, SEXT9(ir));
setMemoryData(getMemoryData(LC3_PC + SEXT9(ir)), LC3_REGS[GET_SR]);
break;
case LC3_STR: // STR instruction
if (LC3_DEBUG&0x01) printf(STR_MSG, oldpc, GET_SR, GET_BASER, SEXT6(ir));
setMemoryData(LC3_REGS[GET_BASER] + SEXT6(ir), LC3_REGS[GET_SR]);
break;
case LC3_TRAP: // TRAP instruction
{
int trapv = getMemoryData(GET_TRAPVECT8); // access trap vector
getMemoryData(trapv); // access system routine
switch(GET_TRAPVECT8)
{ int tmp, string_address;
case LC3_GETID:
{
// Note: This function not supported by simulator.
if (LC3_DEBUG&0x01) printf(TRAP_MSG, oldpc, "GETTID");
//printf("\nLC3_TID = %d (%d)", LC3_TID, curTask);
LC3_REGS[0] = LC3_TID;
LC3_REGS[7] = MASKTO16BITS(LC3_PC);
break;
}
case LC3_GETC:
{
// Note: This does not function quite like GETC.
if (LC3_DEBUG&0x01) printf(TRAP_MSG, oldpc, "GETC");
LC3_REGS[0] = MASKTO8BITS(getCharacter());
LC3_REGS[7] = MASKTO16BITS(LC3_PC);
break;
}
case LC3_OUT:
{
if (LC3_DEBUG&0x01) printf(TRAP_MSG, oldpc, "OUT");
putchar(LC3_REGS[0]);
LC3_REGS[7] = MASKTO16BITS(LC3_PC);
break;
}
case LC3_PUTSP:
{
if (LC3_DEBUG&0x01) printf(TRAP_MSG, oldpc, "PUTSP");
putchar(' ');
LC3_REGS[7] = MASKTO16BITS(LC3_PC);
break;
}
case LC3_PUTS:
{
if (LC3_DEBUG&0x01) printf(TRAP_MSG, oldpc, "PUTS");
string_address = LC3_REGS[0];
while((tmp=getMemoryData(string_address++)) != 0) putchar(tmp);
LC3_REGS[7] = MASKTO16BITS(LC3_PC);
break;
}
case LC3_IN:
{
// Note: This does not function quite like IN.
if (LC3_DEBUG&0x01) printf(TRAP_MSG, oldpc, "IN");
putchar(':');
LC3_REGS[0] = MASKTO8BITS(getCharacter());
LC3_REGS[7] = MASKTO16BITS(LC3_PC);
break;
}
case LC3_HALT:
{
LC3_REGS[7] = MASKTO16BITS(LC3_PC);
if (LC3_DEBUG&0x01) printf(TRAP_MSG, oldpc, "HALT");
printf("\nProcess #%d Halted at 0x%04x\n", LC3_TID, LC3_PC);
charFlag = 0; // release input
return 0;
}
case LC3_getNextDirEntry:
{
// Note: This function not supported by simulator.
// IN: R0 = int *dirNum
// R1 = char* mask
// R2 = DirEntry* dirEntry
// R3 = int cDir
// OUT: R0 = 0-success, otherwise error
if (LC3_DEBUG&0x01) printf(TRAP_MSG, oldpc, "fmsGetNextDirEntry");
LC3_REGS[0] = fmsGetNextDirEntry((int*)getMemAdr(LC3_REGS[0], 1), // int *dirNum
(char*)getMemAdr(LC3_REGS[1], 0), // char* mask
(DirEntry*)getMemAdr(LC3_REGS[2], 1), // DirEntry* dirEntry
(short int)LC3_REGS[3]); // int cDir
SWAP
break;
}
case LC3_closeFile:
{
// Note: This function not supported by simulator.
// IN: R0 = int fileDescriptor
// OUT: R0 = 0-success, otherwise error
if (LC3_DEBUG&0x01) printf(TRAP_MSG, oldpc, "fmsCloseFile");
LC3_REGS[0] = fmsCloseFile((short int)LC3_REGS[0]); // int fileDescriptor
SWAP
break;
}
case LC3_defineFile:
{
// Note: This function not supported by simulator.
// IN: R0 = char* fileName
// OUT: R0 = 0-success, otherwise error
char fileName[32];
char* s = (char*)getMemAdr(LC3_REGS[0], 0);
int j = i = 0;
if(!s[j]) j++;
while((fileName[i++] = s[j])) j+=2;
if (LC3_DEBUG&0x01) printf(TRAP_MSG, oldpc, "fmsCreateFile");
LC3_REGS[0] = fmsDefineFile(fileName, 0); // char* fileName
SWAP
break;
}
case LC3_deleteFile:
{
// Note: This function not supported by simulator.
// IN: R0 = char* fileName
// OUT: R0 = 0-success, otherwise error
char fileName[32];
char* s = (char*)getMemAdr(LC3_REGS[0], 0);
int j = i = 0;
if(!s[j]) j++;
while((fileName[i++] = s[j])) j+=2;
if (LC3_DEBUG&0x01) printf(TRAP_MSG, oldpc, "fmsDeleteFile");
LC3_REGS[0] = fmsDeleteFile(fileName); // char* fileName
SWAP
break;
}
case LC3_openFile:
{
// Note: This function not supported by simulator.
// IN: R0 = char* fileName
// R1 = int rwMode
// OUT: R0 = 0-success, otherwise error
char fileName[32];
char* s = (char*)getMemAdr(LC3_REGS[0], 0);
int j = i = 0;
if(!s[j]) j++;
while((fileName[i++] = s[j])) j+=2;
if (LC3_DEBUG&0x01) printf(TRAP_MSG, oldpc, "fmsOpenFile");
LC3_REGS[0] = fmsOpenFile(fileName, // char* fileName
(short int)LC3_REGS[1]); // int rwMode
SWAP
break;
}
case LC3_readFile:
{
// Note: This function not supported by simulator.
// IN: R0 = int fileDescriptor
// R1 = char* buffer
// R2 = int nBytes
// OUT: R0 = 0-success, otherwise error
if (LC3_DEBUG&0x01) printf(TRAP_MSG, oldpc, "fmsReadFile");
LC3_REGS[0] = fmsReadFile((short int)LC3_REGS[0], // int fileDescriptor
(char*)getMemAdr(LC3_REGS[1], 0), // char* buffer
(short int)LC3_REGS[2]); // int nBytes
SWAP
break;
}
case LC3_seekFile:
{
// Note: This function not supported by simulator.
// IN: R0 = int fileDescriptor
// R1 = int index
// OUT: R0 = 0-success, otherwise error
if (LC3_DEBUG&0x01) printf(TRAP_MSG, oldpc, "fmsSeekFile");
LC3_REGS[0] = fmsSeekFile((short int)LC3_REGS[0], // int fileDescriptor
(short int)LC3_REGS[1]); // int index
SWAP
break;
}
case LC3_writeFile:
{
// Note: This function not supported by simulator.
// IN: R0 = int fileDescriptor
// R1 = char* buffer
// R2 = int nBytes
// OUT: R0 = 0-success, otherwise error
if (LC3_DEBUG&0x01) printf(TRAP_MSG, oldpc, "fmsWriteFile");
LC3_REGS[0] = fmsWriteFile((short int)LC3_REGS[0], // int fileDescriptor
(char*)getMemAdr(LC3_REGS[1], 0), // char* buffer
(short int)LC3_REGS[2]); // int nBytes
SWAP
break;
}
default:
printf(TRAP_ERROR_MSG, GET_TRAPVECT8);
break;
}
break;
}
default:
printf(UNDEFINED_OPCODE_MSG, GET_OPCODE);
return -1; // abort!
}
if (LC3_DEBUG&0x02) // debug mode
{ char cchr[4];
// \n--PC:3000 IR:193b Nzp - 0000 0001 0002 0003 0004 0005 0006 0007
printf("\n--PC:%04x IR:%04x ",LC3_PC, ir);
cchr[0] = (LC3_CC&0x04)?'N':'n';
cchr[1] = (LC3_CC&0x02)?'Z':'z';
cchr[2] = (LC3_CC&0x01)?'P':'p';
cchr[3] = 0;
printf("%s -", &cchr[0]);
for (i=0; i<8; i++) printf(" %04x", LC3_REGS[i]);
//getchar(); // enable to single step
}
// swap tasks every INSTRUCTIONS_PER_SWAP instructions
if (ips++ > INSTRUCTIONS_PER_SWAP)
{ ips = 0;
SWAP
}