FreeCalypso > hg > freecalypso-sw
view miscutil/imei-luhn.c @ 923:10b4bed10192
gsm-fw/L1: fix for the DSP patch corruption bug
The L1 code we got from the LoCosto fw contains a feature for DSP CPU load
measurement. This feature is a LoCosto-ism, i.e., not applicable to earlier
DBB chips (Calypso) with their respective earlier DSP ROMs. Most of the
code dealing with that feature is conditionalized as #if (DSP >= 38),
but one spot was missed, and the MCU code was writing into an API word
dealing with this feature. In TCS211 this DSP API word happens to be
used by the DSP code patch, hence that write was corrupting the patched
DSP code.
author | Mychaela Falconia <falcon@ivan.Harhan.ORG> |
---|---|
date | Mon, 19 Oct 2015 17:13:56 +0000 |
parents | cd043e690621 |
children |
line wrap: on
line source
/* * This program computes the Luhn check digit for an IMEI number given * the first 14 digits, or verifies the correctness of this check digit * given a 15-digit number as input. * * The number given on the command line may optionally include punctuation, * which is skipped and ignored. */ #include <stdio.h> #include <ctype.h> #include <stdlib.h> char digits[15]; compute_cd() { int i, dig, sum; sum = 0; for (i = 0; i < 14; i++) { dig = digits[i]; if (i & 1) { dig *= 2; if (dig > 9) dig -= 9; } sum += dig; } dig = sum % 10; if (dig) dig = 10 - dig; return dig; } main(argc, argv) char **argv; { char *cp; int i; if (argc != 2) { usage: fprintf(stderr, "usage: %s number\n", argv[0]); exit(2); } cp = argv[1]; if (!isdigit(*cp)) goto usage; for (i = 0; *cp; ) { if (ispunct(*cp)) cp++; if (!isdigit(*cp)) goto usage; if (i >= 15) { wrong_len: fprintf(stderr, "error: argument must have 14 or 15 digits\n"); exit(2); } digits[i++] = *cp++ - '0'; } switch (i) { case 14: printf("%d\n", compute_cd()); exit(0); case 15: if (digits[14] == compute_cd()) { printf("IMEI OK\n"); exit(0); } else { printf("Check digit mismatch!\n"); exit(1); } default: goto wrong_len; } }