add osmo_bcd2str()

Add a standalone bcd-to-string conversion function with generic parameters.
Add a regression test in utils_test.c.

So far there is no single universal implementation that converts a BCD to a
string. I could only find gsm48_mi_to_string(), which also interprets
surrounding bytes, MI type and TMSI as non-BCD value.

The idea is to use this function from gsm48_mi_to_string() and similar
implementations in subsequent commits.

Root cause: in osmo-msc, I want to have an alternative MI-to-string function
for composing an FSM name, which needs the BCD part of gsm48_mi_to_string() but
not the TMSI part.

Change-Id: I86b09d37ceef33331c1a56046a5443127d6c6be0

1 files changed, 2 insertions, 0 deletions

diff --git a/include/osmocom/core/utils.h b/include/osmocom/core/utils.h
index 0b54c880..04f2fb4b 100644
--- a/include/osmocom/core/utils.h
+++ b/include/osmocom/core/utils.h
@@ -49,6 +49,8 @@ char osmo_bcd2char(uint8_t bcd);
 /* only works for numbers in ascci */
 uint8_t osmo_char2bcd(char c);
 
+int osmo_bcd2str(char *dst, size_t dst_size, const uint8_t *bcd, int start_nibble, int end_nibble, bool allow_hex);
+
 int osmo_hexparse(const char *str, uint8_t *b, int max_len);
 
 char *osmo_ubit_dump(const uint8_t *bits, unsigned int len);