laforge has uploaded this change for review. ( https://gerrit.osmocom.org/c/libosmocore/+/32650 )

Change subject: Add osmo_gsm48_si1ro_nch_pos_{encode,decode} functions ......................................................................

Add osmo_gsm48_si1ro_nch_pos_{encode,decode} functions

These functions encode/decode the NCH position field within the SI1 rest octets. This is used within ASCI (VBS/VGCS).

Change-Id: I24a0095ac6eee0197f9d9ef9895c7795df6cdc49 Related: OS#5781 --- M src/gsm/gsm48_rest_octets.c M src/gsm/libosmogsm.map 2 files changed, 91 insertions(+), 0 deletions(-)

git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/50/32650/1

diff --git a/src/gsm/gsm48_rest_octets.c b/src/gsm/gsm48_rest_octets.c index 77fd349..b63c63f 100644 --- a/src/gsm/gsm48_rest_octets.c +++ b/src/gsm/gsm48_rest_octets.c @@ -59,6 +59,82 @@ return bv.data_len; }

+struct nch_pos { + uint8_t num_blocks; + uint8_t first_block; +}; + +/* 3GPP TS 44.010 Table 10.5.2.32.1b */ +static const struct nch_pos si1ro_nch_positions[] = { + [0x00] = {1, 0}, + [0x01] = {1, 1}, + [0x02] = {1, 2}, + [0x03] = {1, 3}, + [0x04] = {1, 4}, + [0x05] = {1, 5}, + [0x06] = {1, 6}, + + [0x07] = {2, 0}, + [0x08] = {2, 1}, + [0x08] = {2, 2}, + [0x0a] = {2, 3}, + [0x0b] = {2, 4}, + [0x0c] = {2, 5}, + + [0x0d] = {3, 0}, + [0x0e] = {3, 1}, + [0x0f] = {3, 2}, + [0x10] = {3, 3}, + [0x11] = {3, 4}, + + [0x12] = {4, 0}, + [0x13] = {4, 1}, + [0x14] = {4, 2}, + [0x15] = {4, 3}, + + [0x16] = {5, 0}, + [0x17] = {5, 1}, + [0x18] = {5, 2}, + + [0x19] = {6, 0}, + [0x1a] = {6, 1}, + + [0x1b] = {7, 0}, +}; + +/*! Decode the 5-bit 'NCH position' field within SI1 Rest Octets. + * \param[in] value 5-bit value from SI1 rest octets + * \param[out] num_blocks Number of CCCH used for NCH + * \param[out] first_block First CCCH block used for NCH + * \returns 0 on success; negative in case of error */ +int osmo_gsm48_si1ro_nch_pos_decode(uint8_t value, uint8_t *num_blocks, uint8_t *first_block) +{ + if (value >= ARRAY_SIZE(si1ro_nch_positions)) + return -EINVAL; + + *num_blocks = si1ro_nch_positions[value].num_blocks; + *first_block = si1ro_nch_positions[value].first_block; + + return 0; +} + +/*! Encode the 5-bit 'NCH position' field within SI1 Rest Octets. + * \param[in] num_blocks Number of CCCH used for NCH + * \param[in] first_block First CCCH block used for NCH + * \returns 5-bit value for SI1 rest octets on success; negative in case of error */ +int osmo_gsm48_si1ro_nch_pos_encode(uint8_t num_blocks, uint8_t first_block) +{ + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(si1ro_nch_positions); i++) { + if (si1ro_nch_positions[i].num_blocks == num_blocks && + si1ro_nch_positions[i].first_block == first_block) { + return i; + } + } + return -EINVAL; +} + /* Append Repeated E-UTRAN Neighbour Cell to bitvec: see 3GPP TS 44.018 Table 10.5.2.33b.1 */ static inline bool append_eutran_neib_cell(struct bitvec *bv, const struct osmo_earfcn_si2q *e, size_t *e_offset, uint8_t budget) diff --git a/src/gsm/libosmogsm.map b/src/gsm/libosmogsm.map index 0018e1c..003d6e8 100644 --- a/src/gsm/libosmogsm.map +++ b/src/gsm/libosmogsm.map @@ -336,6 +336,8 @@ osmo_gsm48_rest_octets_si13_encode; osmo_gsm48_rest_octets_si3_decode; osmo_gsm48_rest_octets_si4_decode; +osmo_gsm48_si1ro_nch_pos_encode; +osmo_gsm48_si1ro_nch_pos_decode; gsm48_rr_short_pd_msg_name; gsm48_rr_msg_name; gsm48_cc_state_name;