--- a/.hgignore	Fri Nov 27 03:53:11 2020 +0000
+++ b/.hgignore	Fri Nov 27 04:39:38 2020 +0000
@@ -43,6 +43,7 @@
 ^miscutil/make-imeisv$
 ^miscutil/mokosrec2bin$
 ^miscutil/srec-regions$
+^miscutil/ti2arfcn$
 
 ^ringtools/fc-e1decode$
 ^ringtools/fc-e1gen$

--- a/miscutil/Makefile	Fri Nov 27 03:53:11 2020 +0000
+++ b/miscutil/Makefile	Fri Nov 27 04:39:38 2020 +0000
@@ -2,7 +2,7 @@
 CFLAGS=	-O2
 PROGS=	arfcn2ti fc-fr2tch fc-gsm2vm fc-pulse-dtr fc-pulse-rts fc-rgbconv \
 	fc-serterm fc-tch2fr fc-vm2hex imei-luhn make-imeisv mokosrec2bin \
-	srec-regions
+	srec-regions ti2arfcn
 SCRIPTS=c139explore pirexplore
 
 INSTALL_PREFIX=	/opt/freecalypso
@@ -58,6 +58,9 @@
 srec-regions:	srec-regions.c
 	${CC} ${CFLAGS} -o $@ $@.c
 
+ti2arfcn:	ti2arfcn.c
+	${CC} ${CFLAGS} -o $@ $@.c
+
 install:
 	mkdir -p ${INSTBIN}
 	install -c ${PROGS} ${SCRIPTS} ${INSTBIN}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/miscutil/ti2arfcn.c	Fri Nov 27 04:39:38 2020 +0000
@@ -0,0 +1,73 @@
+/*
+ * TI's TCS211 L1 does not use standard ARFCNs internally, instead it uses
+ * its own non-standard radio_freq numbers in their place.  Other firmware
+ * components and all external interfaces do use standard ARFCNs, thus
+ * conversion functions are invoked at appropriate points in the firmware.
+ * However, L1-internal radio_freq numbers are emitted in L1 debug traces,
+ * thus anyone looking at these traces needs to be able to convert between
+ * standard ARFCNs and L1-internal radio_freq.
+ *
+ * The present utility converts TI's radio_freq numbers as seen in L1 traces
+ * into standard ARFCNs.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+
+main(argc, argv)
+	char **argv;
+{
+	int ti_num;
+
+	if (argc != 3) {
+usage:		fprintf(stderr, "usage: %s {eu|us} L1_radio_freq\n", argv[0]);
+		exit(1);
+	}
+	ti_num = atoi(argv[2]);
+	if (!strcmp(argv[1], "eu"))
+		ti2arfcn_eu(ti_num);
+	else if (!strcmp(argv[1], "us"))
+		ti2arfcn_us(ti_num);
+	else
+		goto usage;
+	exit(0);
+}
+
+ti2arfcn_eu(radio_freq)
+{
+	int arfcn;
+
+	if (radio_freq < 1 || radio_freq > 548) {
+		fprintf(stderr,
+		"error: specified radio_freq is out of range for dual-EU\n");
+		exit(1);
+	}
+	if (radio_freq < 175) {
+		if (radio_freq <= 124)
+			arfcn = radio_freq;
+		else if (radio_freq < 174)
+			arfcn = radio_freq - 125 + 975;
+		else
+			arfcn = 0;
+	} else
+		arfcn = radio_freq - 175 + 512;
+	printf("%d\n", arfcn);
+}
+
+ti2arfcn_us(radio_freq)
+{
+	int arfcn;
+
+	if (radio_freq < 1 || radio_freq > 423) {
+		fprintf(stderr,
+		"error: specified radio_freq is out of range for dual-US\n");
+		exit(1);
+	}
+	if (radio_freq < 125)
+		arfcn = radio_freq - 1 + 128;
+	else
+		arfcn = radio_freq - 125 + 512;
+	printf("%d\n", arfcn);
+}