+ int sz;
+ char *bptr = sb->buf;
+ char *start = sb->buf;
+ char *end = sb->buf + sb->len;
+
+ /* see if we have a CR in the buffer */
+ while(bptr < end) {
+ if(*bptr == '\r') {
+ *bptr = 0;
+ mag_parsepkt(*start, start + 1, bptr - start - 1);
+ start = ++bptr;
+ } else {
+ bptr++;
+ }
+ }
+
+ sz = start - sb->buf;
+ if(sz > 0) {
+ memmove(sb->buf, start, sz);
+ sb->len -= sz;
+ }
+ return 0;
+}
+
+static int mag_parsepkt(int id, char *data, int len)
+{
+ int i, mot[6];
+ unsigned int keystate;
+
+ /*printf("magellan packet: %c - %s (%d bytes)\n", (char)id, data, len);*/
+
+ switch(id) {
+ case 'd':
+ if(len != 24) {
+ fprintf(stderr, "magellan: invalid data packet, expected 24 bytes, got: %d\n", len);
+ return -1;
+ }
+ for(i=0; i<6; i++) {
+ mot[i] = ((((int)data[0] & 0xf) << 12) | (((int)data[1] & 0xf) << 8) |
+ (((int)data[2] & 0xf) << 4) | (data[3] & 0xf)) - 0x8000;
+ data += 4;
+ }
+ printf("motion: T %+4d %+4d %+4d R %+4d %+4d %+4d\n", mot[0], mot[1], mot[2], mot[3], mot[4], mot[5]);
+ break;
+
+ case 'k':
+ if(len != 3) {
+ fprintf(stderr, "magellan: invalid keyboard pakcet, expected 3 bytes, got: %d\n", len);
+ return -1;
+ }
+ keystate = (data[0] & 0xf) | ((data[1] & 0xf) << 4) | (((unsigned int)data[2] & 0xf) << 8);
+ printf("keystate: ");
+ for(i=0; i<12; i++) {
+ int b = 11 - i;
+ int hex = b < 10 ? b + '0' : b - 10 + 'a';
+ putchar(keystate & (1 << b) ? hex : '-');
+ }
+ putchar('\n');
+ break;
+
+ case 'e':
+ if(data[0] == 1) {
+ fprintf(stderr, "magellan error: illegal command: %c%c\n", data[1], data[2]);
+ } else if(data[0] == 2) {
+ fprintf(stderr, "magellan error: framing error\n");
+ } else {
+ fprintf(stderr, "magellan error: unknown device error\n");
+ }
+ return -1;
+
+ default:
+ break;
+ }
+ return 0;