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6502-emu
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Added usage statement

This commit is contained in:
Rob McMullen 2017-12-19 18:33:13 -08:00
parent ff67a94658
commit 99aac0a85f
1 changed files with 31 additions and 7 deletions
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38
6502-emu.c
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@ -67,6 +67,29 @@ int hextoint(char *str) {
return val;
}
void usage(char *argv[]) {
fprintf(stderr, "Usage: %s [OPTIONS] FILE\n"
"Simulate a NMOS 6502 processor\n"
"\nOPTIONS:\n"
"\n CPU Initialization (specify all values in hex; $nn, 0xNN, etc.)\n"
" -a HEX set A register (default 0)\n"
" -x HEX set X register (default 0)\n"
" -y HEX set Y register (default 0)\n"
" -s HEX set stack pointer (default $ff)\n"
" -p HEX set processor status register (default 0)\n"
" -r ADDR set initial run address (default: use value at RST_VEC)\n"
"\n Emulator Control\n"
" -v print CPU info at every step\n"
" -i connect stdin/stdout to the emulator\n"
" -b ADDR stop when PC reaches this address, write memory dump, and exit\n"
" -c NUM exit after number of cycles (default: never)\n"
" -f run as fast as possible; no delay loop\n"
"\n Memory Initialization\n"
" -l ADDR load address for ROM file (default $c000)\n"
" FILE binary file to load\n"
, argv[0]);
}
int main(int argc, char *argv[])
{
int a, x, y, sp, sr, pc, load_addr;
@ -87,7 +110,7 @@ int main(int argc, char *argv[])
sp = 0;
sr = 0;
pc = -RST_VEC; // negative implies indirect
while ((opt = getopt(argc, argv, "vimfa:b:x:y:r:p:s:g:c:l:")) != -1) {
while ((opt = getopt(argc, argv, "hvimfa:b:x:y:r:p:s:g:c:l:")) != -1) {
switch (opt) {
case 'v':
verbose = 1;
@ -129,15 +152,16 @@ int main(int argc, char *argv[])
case 'l':
load_addr = hextoint(optarg);
break;
default: /* '?' */
fprintf(stderr, "Usage: %s [-v] [-i] [-a HEX] [-x HEX] [-y HEX] [-s HEX] [-p HEX] [-g|-r ADDR] file.rom\nThe first 16k of \"file.rom\" is loaded into the last 16k of memory.\n",
argv[0]);
exit(EXIT_FAILURE);
}
case 'h':
default: /* '?' */
usage(argv);
exit(EXIT_FAILURE);
}
}
if (optind >= argc) {
fprintf(stderr, "Expected argument after options\n");
fprintf(stderr, "Error: expected binary file to load\n\n");
usage(argv);
exit(EXIT_FAILURE);
}
if (load_rom(argv[optind], load_addr) != 0) {