/*
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/*
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* main.c -- start the ball rolling
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* main.c -- start the ball rolling
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*/
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*/
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#include "stdarg.h"
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#include "stdarg.h"
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#include "start.h"
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#include "start.h"
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/**************************************************************/
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/**************************************************************/
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void putchar(char c) {
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void putchar(char c) {
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unsigned int *base;
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unsigned int *base;
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if (c == '\n') {
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if (c == '\n') {
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putchar('\r');
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putchar('\r');
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}
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}
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base = (unsigned int *) 0xF0300000;
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base = (unsigned int *) 0xF0300000;
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while ((*(base + 2) & 1) == 0) ;
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while ((*(base + 2) & 1) == 0) ;
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*(base + 3) = c;
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*(base + 3) = c;
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}
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}
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void puts(char *s) {
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void puts(char *s) {
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char c;
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char c;
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while ((c = *s++) != '\0') {
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while ((c = *s++) != '\0') {
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putchar(c);
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putchar(c);
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}
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}
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}
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}
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void printn(int n) {
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void printn(int n) {
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int a;
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int a;
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if (n < 0) {
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if (n < 0) {
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putchar('-');
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putchar('-');
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n = -n;
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n = -n;
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}
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}
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a = n / 10;
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a = n / 10;
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if (a != 0) {
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if (a != 0) {
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printn(a);
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printn(a);
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}
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}
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putchar(n % 10 + '0');
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putchar(n % 10 + '0');
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}
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}
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void printu(unsigned int n, unsigned int b) {
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void printu(unsigned int n, unsigned int b) {
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unsigned int a;
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unsigned int a;
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a = n / b;
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a = n / b;
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if (a != 0) {
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if (a != 0) {
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printu(a, b);
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printu(a, b);
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}
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}
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putchar("0123456789ABCDEF"[n % b]);
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putchar("0123456789ABCDEF"[n % b]);
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}
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}
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void printf(char *fmt, ...) {
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void printf(char *fmt, ...) {
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va_list ap;
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va_list ap;
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char c;
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char c;
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int n;
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int n;
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unsigned int u;
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unsigned int u;
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char *s;
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char *s;
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va_start(ap, fmt);
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va_start(ap, fmt);
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while (1) {
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while (1) {
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while ((c = *fmt++) != '%') {
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while ((c = *fmt++) != '%') {
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if (c == '\0') {
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if (c == '\0') {
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va_end(ap);
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va_end(ap);
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return;
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return;
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}
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}
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putchar(c);
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putchar(c);
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}
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}
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c = *fmt++;
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c = *fmt++;
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if (c == 'd') {
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if (c == 'd') {
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n = va_arg(ap, int);
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n = va_arg(ap, int);
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printn(n);
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printn(n);
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} else
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} else
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if (c == 'u' || c == 'o' || c == 'x') {
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if (c == 'u' || c == 'o' || c == 'x') {
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u = va_arg(ap, int);
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u = va_arg(ap, int);
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printu(u, c == 'o' ? 8 : (c == 'x' ? 16 : 10));
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printu(u, c == 'o' ? 8 : (c == 'x' ? 16 : 10));
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} else
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} else
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if (c == 's') {
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if (c == 's') {
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s = va_arg(ap, char *);
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s = va_arg(ap, char *);
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puts(s);
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puts(s);
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} else {
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} else {
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putchar(c);
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putchar(c);
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}
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}
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}
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}
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}
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}
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/**************************************************************/
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/**************************************************************/
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static char *exceptionCause[32] = {
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static char *exceptionCause[32] = {
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/* 00 */ "terminal 0 transmitter interrupt",
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/* 00 */ "terminal 0 transmitter interrupt",
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/* 01 */ "terminal 0 receiver interrupt",
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/* 01 */ "terminal 0 receiver interrupt",
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/* 02 */ "terminal 1 transmitter interrupt",
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/* 02 */ "terminal 1 transmitter interrupt",
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/* 03 */ "terminal 1 receiver interrupt",
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/* 03 */ "terminal 1 receiver interrupt",
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/* 04 */ "keyboard interrupt",
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/* 04 */ "keyboard interrupt",
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/* 05 */ "unknown interrupt",
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/* 05 */ "unknown interrupt",
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/* 06 */ "unknown interrupt",
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/* 06 */ "unknown interrupt",
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/* 07 */ "unknown interrupt",
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/* 07 */ "unknown interrupt",
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/* 08 */ "disk interrupt",
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/* 08 */ "disk interrupt",
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/* 09 */ "unknown interrupt",
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/* 09 */ "unknown interrupt",
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/* 10 */ "unknown interrupt",
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/* 10 */ "unknown interrupt",
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/* 11 */ "unknown interrupt",
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/* 11 */ "unknown interrupt",
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/* 12 */ "unknown interrupt",
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/* 12 */ "unknown interrupt",
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/* 13 */ "unknown interrupt",
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/* 13 */ "unknown interrupt",
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/* 14 */ "timer interrupt",
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/* 14 */ "timer 0 interrupt",
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/* 15 */ "unknown interrupt",
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/* 15 */ "timer 1 interrupt",
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/* 16 */ "bus timeout exception",
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/* 16 */ "bus timeout exception",
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/* 17 */ "illegal instruction exception",
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/* 17 */ "illegal instruction exception",
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/* 18 */ "privileged instruction exception",
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/* 18 */ "privileged instruction exception",
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/* 19 */ "divide instruction exception",
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/* 19 */ "divide instruction exception",
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/* 20 */ "trap instruction exception",
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/* 20 */ "trap instruction exception",
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/* 21 */ "TLB miss exception",
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/* 21 */ "TLB miss exception",
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/* 22 */ "TLB write exception",
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/* 22 */ "TLB write exception",
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/* 23 */ "TLB invalid exception",
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/* 23 */ "TLB invalid exception",
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/* 24 */ "illegal address exception",
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/* 24 */ "illegal address exception",
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/* 25 */ "privileged address exception",
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/* 25 */ "privileged address exception",
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/* 26 */ "unknown exception",
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/* 26 */ "unknown exception",
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/* 27 */ "unknown exception",
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/* 27 */ "unknown exception",
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/* 28 */ "unknown exception",
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/* 28 */ "unknown exception",
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/* 29 */ "unknown exception",
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/* 29 */ "unknown exception",
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/* 30 */ "unknown exception",
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/* 30 */ "unknown exception",
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/* 31 */ "unknown exception"
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/* 31 */ "unknown exception"
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};
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};
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int defaultISR(int irq) {
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int defaultISR(int irq) {
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printf("\n%s\n", exceptionCause[irq]);
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printf("\n%s\n", exceptionCause[irq]);
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return 0; /* do not skip any instruction */
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return 0; /* do not skip any instruction */
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}
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}
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void initInterrupts(void) {
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void initInterrupts(void) {
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int i;
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int i;
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for (i = 0; i < 32; i++) {
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for (i = 0; i < 32; i++) {
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setISR(i, defaultISR);
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setISR(i, defaultISR);
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}
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}
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}
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}
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/**************************************************************/
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/**************************************************************/
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static int busTimeoutSeen;
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static int busTimeoutSeen;
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int busTimeoutISR(int irq) {
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int busTimeoutISR(int irq) {
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busTimeoutSeen = 1;
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busTimeoutSeen = 1;
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return 1; /* skip offending instruction */
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return 1; /* skip offending instruction */
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}
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}
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int memsize(void) {
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int memsize(void) {
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unsigned char *ptr;
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unsigned char *ptr;
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unsigned char b;
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unsigned char b;
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ISR oldService;
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ISR oldService;
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busTimeoutSeen = 0;
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busTimeoutSeen = 0;
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oldService = getISR(16);
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oldService = getISR(16);
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setISR(16, busTimeoutISR);
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setISR(16, busTimeoutISR);
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ptr = (unsigned char *) 0xC0000000;
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ptr = (unsigned char *) 0xC0000000;
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while (1) {
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while (1) {
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b = *ptr;
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b = *ptr;
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if (busTimeoutSeen) {
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if (busTimeoutSeen) {
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break;
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break;
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}
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}
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ptr += (1 << 12);
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ptr += (1 << 12);
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}
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}
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setISR(16, oldService);
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setISR(16, oldService);
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return (ptr - (unsigned char *) 0xC0000000) >> 12;
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return (ptr - (unsigned char *) 0xC0000000) >> 12;
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}
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}
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/**************************************************************/
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/**************************************************************/
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void main(void) {
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void main(void) {
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int numberPages;
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int numberPages;
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initInterrupts();
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initInterrupts();
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printf("\n");
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printf("\n");
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printf("Probing memory...\n");
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printf("Probing memory...\n");
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numberPages = memsize();
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numberPages = memsize();
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printf("Memory size = %d pages * 4 Kbytes\n", numberPages);
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printf("Memory size = %d pages * 4 Kbytes\n", numberPages);
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printf("Halting...\n");
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printf("Halting...\n");
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}
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}
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