AtomBusMon/firmware/AtomBusMon.c

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#include <stdio.h>
#include <string.h>
#include <avr/pgmspace.h>
#include "hd44780.h"
#include "status.h"
#define CTRL_PORT PORTB
#define CTRL_DDR DDRB
#define CTRL_DIN PINB
// Outputs
#define STEP_MASK 0x01
#define SINGLE_MASK 0x02
#define RESET_MASK 0x04
#define BRKPT_ENABLE_MASK 0x08
#define BRKPT_CLOCK_MASK 0x10
#define BRKPT_DATA_MASK 0x20
// Inputs
#define BRKPT_INTERRUPTED_MASK 0x40
#define BRKPT_ACTIVE_MASK 0x80
// Breakpoint Modes
#define BRKPT_INSTR 0x01
#define BRKPT_READ 0x02
#define BRKPT_WRITE 0x04
char *brkptStrings[8] = {
"No breakpoint",
"Instruction breakpoint",
"Read breakpoint",
"Instruction, read breakpoints",
"Write breakpoint",
"Instruction, write breakpoints",
"Read, write breakpoints",
"Instruction, read, write breakpoints"
};
#define CTRL_MASK (SINGLE_MASK | STEP_MASK | RESET_MASK | BRKPT_ENABLE_MASK | BRKPT_CLOCK_MASK | BRKPT_DATA_MASK)
#define AL_PORT PORTD
#define AL_DIN PIND
#define AL_MASK 0x00
#define AL_DDR DDRD
#define AH_PORT PORTE
#define AH_DIN PINE
#define AH_MASK 0x00
#define AH_DDR DDRE
#define VERSION "0.11"
#define NUMCMDS 12
#define MAXBKPTS 4
int numbkpts = 0;
int single;
long trace;
long instructions = 1;
unsigned int breakpoints[MAXBKPTS] = {
0,
0,
0,
0
};
unsigned int modes[MAXBKPTS] = {
0,
0,
0,
0
};
char *cmdStrings[NUMCMDS] = {
"help",
"reset",
"interrupt",
"address",
"step",
"trace",
"blist",
"breaki",
"breakr",
"breakw",
"bclear",
"continue",
};
#define Delay_us(__us) \
if((unsigned long) (F_CPU/1000000.0 * __us) != F_CPU/1000000.0 * __us)\
__builtin_avr_delay_cycles((unsigned long) ( F_CPU/1000000.0 * __us)+1);\
else __builtin_avr_delay_cycles((unsigned long) ( F_CPU/1000000.0 * __us))
#define Delay_ms(__ms) \
if((unsigned long) (F_CPU/1000.0 * __ms) != F_CPU/1000.0 * __ms)\
__builtin_avr_delay_cycles((unsigned long) ( F_CPU/1000.0 * __ms)+1);\
else __builtin_avr_delay_cycles((unsigned long) ( F_CPU/1000.0 * __ms))
char message[32];
char command[32];
void readCmd(char *cmd) {
char c;
int i = 0;
log0(">> ");
while (1) {
c = Serial_RxByte0();
if (c == 8) {
// Handle backspace/delete
if (i > 0) {
i--;
Serial_TxByte0(c);
Serial_TxByte0(32);
Serial_TxByte0(c);
}
} else if (c == 13) {
// Handle return
if (i == 0) {
while (cmd[i]) {
Serial_TxByte0(cmd[i++]);
}
} else {
cmd[i] = 0;
}
Serial_TxByte0(10);
Serial_TxByte0(13);
return;
} else {
// Handle any other character
Serial_TxByte0(c);
cmd[i] = c;
i++;
}
}
}
void setSingle(int i) {
single = i;
if (single) {
CTRL_PORT |= SINGLE_MASK;
} else {
CTRL_PORT &= ~SINGLE_MASK;
}
Delay_us(10);
}
void setTrace(long i) {
trace = i;
if (trace) {
log0("Tracing every %ld instructions while single stepping\n", trace);
} else {
log0("Tracing disabled\n");
}
}
void version() {
log0("Atom Bus Monitor version %s\n", VERSION);
log0("Compiled at %s on %s\n",__TIME__,__DATE__);
}
/*******************************************
* Commands
*******************************************/
void doCmdHelp(char *params) {
int i;
version();
log0("Commands:\n");
for (i = 0; i < NUMCMDS; i++) {
log0(" %s\n", cmdStrings[i]);
}
}
void doCmdAddr() {
int i, nibble;
unsigned int addr = AH_DIN << 8 | AL_DIN;
// Update the serial port
log0("%04X\n", addr);
// Update the LCD display
lcd_goto(6);
// Avoid using sprintf, as it adds quite a lot of code
for (i = 3; i >= 0; i--) {
nibble = addr >> (i * 4);
nibble &= 0x0F;
nibble += '0';
if (nibble > '9') {
nibble += 'A' - '9' - 1;
}
lcd_putc(nibble);
}
}
void doCmdStep(char *params) {
long i;
long j;
if (!single) {
log0("Use the break command to stop the 6502\n");
return;
}
sscanf(params, "%ld", &instructions);
if (instructions <= 0) {
log0("Number of instuctions must be positive\n");
return;
}
log0("Stepping %ld instructions\n", instructions);
j = trace;
for (i = 1; i <= instructions; i++) {
// Step the 6502
CTRL_PORT &= ~STEP_MASK;
Delay_us(2);
CTRL_PORT |= STEP_MASK;
Delay_us(2);
if (i == instructions || (trace && (--j == 0))) {
Delay_us(10);
doCmdAddr();
j = trace;
}
}
}
void doCmdReset(char *params) {
log0("Resetting 6502\n");
CTRL_PORT |= RESET_MASK;
Delay_us(100);
CTRL_PORT &= ~RESET_MASK;
}
void doCmdInterrupt(char *params) {
setSingle(1);
doCmdAddr();
}
void doCmdTrace(char *params) {
long i;
sscanf(params, "%ld", &i);
setTrace(i);
}
void doCmdBList(char *params) {
int i;
if (numbkpts) {
for (i = 0; i < numbkpts; i++) {
log0("%d: %04X %s\n", i, breakpoints[i], brkptStrings[modes[i]]);
}
} else {
log0("No breakpoints set\n");
}
}
void setBreakpoint(int i, int addr, int mode) {
log0("%s set at %04X\n", brkptStrings[mode], addr);
breakpoints[i] = addr;
modes[i] = mode;
}
void doCmdBreak(char *params, unsigned int mode) {
int i;
unsigned int addr;
sscanf(params, "%x", &addr);
for (i = 0; i < numbkpts; i++) {
if (breakpoints[i] == addr) {
if (modes[i] & mode) {
log0("%s already set at %04X\n", brkptStrings[mode], addr);
} else {
setBreakpoint(i, addr, modes[i] | mode);
}
doCmdBList(NULL);
return;
}
}
if (numbkpts == MAXBKPTS) {
log0("All breakpoints are already set\n");
doCmdBList(NULL);
return;
}
numbkpts++;
for (i = numbkpts - 2; i >= -1; i--) {
if (i == -1 || breakpoints[i] < addr) {
setBreakpoint(i + 1, addr, mode);
doCmdBList(NULL);
return;
} else {
breakpoints[i + 1] = breakpoints[i];
modes[i + 1] = modes[i];
}
}
}
void doCmdBreakI(char *params) {
doCmdBreak(params, BRKPT_INSTR);
}
void doCmdBreakR(char *params) {
doCmdBreak(params, BRKPT_READ);
}
void doCmdBreakW(char *params) {
doCmdBreak(params, BRKPT_WRITE);
}
void doCmdBClear(char *params) {
int i;
int n = 0;
sscanf(params, "%d", &n);
if (n >= numbkpts) {
log0("Breakpoint %d not set\n", n);
} else {
log0("Removing %s at %04X\n", brkptStrings[modes[n]], breakpoints[n]);
for (i = n; i < numbkpts; i++) {
breakpoints[i] = breakpoints[i + 1];
modes[i] = modes[i + 1];
}
numbkpts--;
}
doCmdBList(NULL);
}
void shiftBreakpointRegister(unsigned int addr, unsigned int mode) {
int i;
long reg = mode;
reg <<= 16;
reg |= addr;
for (i = 0; i < 20; i++) {
CTRL_PORT &= ~BRKPT_CLOCK_MASK;
if (reg & 1) {
CTRL_PORT |= BRKPT_DATA_MASK;
} else {
CTRL_PORT &= ~BRKPT_DATA_MASK;
}
Delay_us(10);
CTRL_PORT |= BRKPT_CLOCK_MASK;
Delay_us(10);
reg >>= 1;
}
}
void doCmdContinue(char *params) {
int i;
int status;
doCmdBList(NULL);
// Disable breakpoints to allow loading
CTRL_PORT &= ~BRKPT_ENABLE_MASK;
// Load breakpoints into comparators
for (i = 0; i < numbkpts; i++) {
shiftBreakpointRegister(breakpoints[i], modes[i]);
}
for (i = numbkpts; i < MAXBKPTS; i++) {
shiftBreakpointRegister(0, 0);
}
// Enable breakpoints
CTRL_PORT |= BRKPT_ENABLE_MASK;
// Disable single stepping
setSingle(0);
// Wait for breakpoint to become active
log0("6502 free running...\n");
do {
status = CTRL_DIN;
} while (!(status & BRKPT_ACTIVE_MASK) && !(status && BRKPT_INTERRUPTED_MASK));
// Output cause
if (status & BRKPT_ACTIVE_MASK) {
log0("Breakpoint hit at ");
} else {
log0("Interrupted at ");
}
doCmdAddr();
// Enable single stepping
setSingle(1);
// Disable breakpoints
CTRL_PORT &= ~BRKPT_ENABLE_MASK;
}
void initialize() {
CTRL_DDR = CTRL_MASK;
AL_DDR = AL_MASK;
AH_DDR = AH_MASK;
CTRL_PORT &= 0;
Serial_Init(57600,57600);
lcd_init();
lcd_puts("Addr: xxxx");
version();
setSingle(1);
setTrace(1);
log0("6502 paused...\n");
doCmdAddr();
}
void (*cmdFuncs[NUMCMDS])(char *params) = {
doCmdHelp,
doCmdReset,
doCmdInterrupt,
doCmdAddr,
doCmdStep,
doCmdTrace,
doCmdBList,
doCmdBreakI,
doCmdBreakR,
doCmdBreakW,
doCmdBClear,
doCmdContinue
};
void dispatchCmd(char *cmd) {
int i;
char *cmdString;
int minLen;
int cmdStringLen;
int cmdLen = 0;
while (cmd[cmdLen] >= 'a' && cmd[cmdLen] <= 'z') {
cmdLen++;
}
for (i = 0; i < NUMCMDS; i++) {
cmdString = cmdStrings[i];
cmdStringLen = strlen(cmdString);
minLen = cmdLen < cmdStringLen ? cmdLen : cmdStringLen;
if (strncmp(cmdString, cmd, minLen) == 0) {
(*cmdFuncs[i])(command + cmdLen);
return;
}
}
log0("Unknown command %s\n", cmd);
}
int main(void) {
initialize();
while (1) {
readCmd(command);
dispatchCmd(command);
}
return 0;
}