diff --git a/lib/decoding/osmocom/core/bitvec.c b/lib/decoding/osmocom/core/bitvec.c
new file mode 100644
index 0000000..414c719
--- /dev/null
+++ b/lib/decoding/osmocom/core/bitvec.c
@@ -0,0 +1,708 @@
+/* (C) 2009 by Harald Welte <laforge@gnumonks.org>
+ * (C) 2012 Ivan Klyuchnikov
+ * (C) 2015 by sysmocom - s.f.m.c. GmbH
+ *
+ * All Rights Reserved
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+/*! \addtogroup bitvec
+ *  @{
+ *  Osmocom bit vector abstraction utility routines.
+ *
+ *  These functions assume a MSB (most significant bit) first layout of the
+ *  bits, so that for instance the 5 bit number abcde (a is MSB) can be
+ *  embedded into a byte sequence like in xxxxxxab cdexxxxx. The bit count
+ *  starts with the MSB, so the bits in a byte are numbered (MSB) 01234567 (LSB).
+ *  Note that there are other incompatible encodings, like it is used
+ *  for the EGPRS RLC data block headers (there the bits are numbered from LSB
+ *  to MSB).
+ *
+ * \file bitvec.c */
+
+#include <errno.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdbool.h>
+
+#include <osmocom/core/bits.h>
+#include <osmocom/core/bitvec.h>
+
+#define BITNUM_FROM_COMP(byte, bit)	((byte*8)+bit)
+
+static inline unsigned int bytenum_from_bitnum(unsigned int bitnum)
+{
+	unsigned int bytenum = bitnum / 8;
+
+	return bytenum;
+}
+
+/* convert ZERO/ONE/L/H to a bitmask at given pos in a byte */
+static uint8_t bitval2mask(enum bit_value bit, uint8_t bitnum)
+{
+	int bitval;
+
+	switch (bit) {
+	case ZERO:
+		bitval = (0 << bitnum);
+		break;
+	case ONE:
+		bitval = (1 << bitnum);
+		break;
+	case L:
+		bitval = ((0x2b ^ (0 << bitnum)) & (1 << bitnum));
+		break;
+	case H:
+		bitval = ((0x2b ^ (1 << bitnum)) & (1 << bitnum));
+		break;
+	default:
+		return 0;
+	}
+	return bitval;
+}
+
+/*! check if the bit is 0 or 1 for a given position inside a bitvec
+ *  \param[in] bv the bit vector on which to check
+ *  \param[in] bitnr the bit number inside the bit vector to check
+ *  \return value of the requested bit
+ */
+enum bit_value bitvec_get_bit_pos(const struct bitvec *bv, unsigned int bitnr)
+{
+	unsigned int bytenum = bytenum_from_bitnum(bitnr);
+	unsigned int bitnum = 7 - (bitnr % 8);
+	uint8_t bitval;
+
+	if (bytenum >= bv->data_len)
+		return -EINVAL;
+
+	bitval = bitval2mask(ONE, bitnum);
+
+	if (bv->data[bytenum] & bitval)
+		return ONE;
+
+	return ZERO;
+}
+
+/*! check if the bit is L or H for a given position inside a bitvec
+ *  \param[in] bv the bit vector on which to check
+ *  \param[in] bitnr the bit number inside the bit vector to check
+ *  \return value of the requested bit
+ */
+enum bit_value bitvec_get_bit_pos_high(const struct bitvec *bv,
+					unsigned int bitnr)
+{
+	unsigned int bytenum = bytenum_from_bitnum(bitnr);
+	unsigned int bitnum = 7 - (bitnr % 8);
+	uint8_t bitval;
+
+	if (bytenum >= bv->data_len)
+		return -EINVAL;
+
+	bitval = bitval2mask(H, bitnum);
+
+	if ((bv->data[bytenum] & (1 << bitnum)) == bitval)
+		return H;
+
+	return L;
+}
+
+/*! get the Nth set bit inside the bit vector
+ *  \param[in] bv the bit vector to use
+ *  \param[in] n the bit number to get
+ *  \returns the bit number (offset) of the Nth set bit in \a bv
+ */
+unsigned int bitvec_get_nth_set_bit(const struct bitvec *bv, unsigned int n)
+{
+	unsigned int i, k = 0;
+
+	for (i = 0; i < bv->data_len*8; i++) {
+		if (bitvec_get_bit_pos(bv, i) == ONE) {
+			k++;
+			if (k == n)
+				return i;
+		}
+	}
+
+	return 0;
+}
+
+/*! set a bit at given position in a bit vector
+ *  \param[in] bv bit vector on which to operate
+ *  \param[in] bitnr number of bit to be set
+ *  \param[in] bit value to which the bit is to be set
+ *  \returns 0 on success, negative value on error
+ */
+inline int bitvec_set_bit_pos(struct bitvec *bv, unsigned int bitnr,
+			enum bit_value bit)
+{
+	unsigned int bytenum = bytenum_from_bitnum(bitnr);
+	unsigned int bitnum = 7 - (bitnr % 8);
+	uint8_t bitval;
+
+	if (bytenum >= bv->data_len)
+		return -EINVAL;
+
+	/* first clear the bit */
+	bitval = bitval2mask(ONE, bitnum);
+	bv->data[bytenum] &= ~bitval;
+
+	/* then set it to desired value */
+	bitval = bitval2mask(bit, bitnum);
+	bv->data[bytenum] |= bitval;
+
+	return 0;
+}
+
+/*! set the next bit inside a bitvec
+ *  \param[in] bv bit vector to be used
+ *  \param[in] bit value of the bit to be set
+ *  \returns 0 on success, negative value on error
+ */
+inline int bitvec_set_bit(struct bitvec *bv, enum bit_value bit)
+{
+	int rc;
+
+	rc = bitvec_set_bit_pos(bv, bv->cur_bit, bit);
+	if (!rc)
+		bv->cur_bit++;
+
+	return rc;
+}
+
+/*! get the next bit (low/high) inside a bitvec
+ *  \return value of th next bit in the vector */
+int bitvec_get_bit_high(struct bitvec *bv)
+{
+	int rc;
+
+	rc = bitvec_get_bit_pos_high(bv, bv->cur_bit);
+	if (rc >= 0)
+		bv->cur_bit++;
+
+	return rc;
+}
+
+/*! set multiple bits (based on array of bitvals) at current pos
+ *  \param[in] bv bit vector
+ *  \param[in] bits array of \ref bit_value
+ *  \param[in] count number of bits to set
+ *  \return 0 on success; negative in case of error */
+int bitvec_set_bits(struct bitvec *bv, const enum bit_value *bits, unsigned int count)
+{
+	int i, rc;
+
+	for (i = 0; i < count; i++) {
+		rc = bitvec_set_bit(bv, bits[i]);
+		if (rc)
+			return rc;
+	}
+
+	return 0;
+}
+
+/*! set multiple bits (based on numeric value) at current pos.
+ *  \param[in] bv bit vector.
+ *  \param[in] v mask representing which bits needs to be set.
+ *  \param[in] num_bits number of meaningful bits in the mask.
+ *  \param[in] use_lh whether to interpret the bits as L/H values or as 0/1.
+ *  \return 0 on success; negative in case of error. */
+int bitvec_set_u64(struct bitvec *bv, uint64_t v, uint8_t num_bits, bool use_lh)
+{
+	uint8_t i;
+
+	if (num_bits > 64)
+		return -E2BIG;
+
+	for (i = 0; i < num_bits; i++) {
+		int rc;
+		enum bit_value bit = use_lh ? L : 0;
+
+		if (v & ((uint64_t)1 << (num_bits - i - 1)))
+			bit = use_lh ? H : 1;
+
+		rc = bitvec_set_bit(bv, bit);
+		if (rc != 0)
+			return rc;
+	}
+
+	return 0;
+}
+
+/*! set multiple bits (based on numeric value) at current pos.
+ *  \return 0 in case of success; negative in case of error. */
+int bitvec_set_uint(struct bitvec *bv, unsigned int ui, unsigned int num_bits)
+{
+	return bitvec_set_u64(bv, ui, num_bits, false);
+}
+
+/*! get multiple bits (num_bits) from beginning of vector (MSB side)
+ *  \return 16bit signed integer retrieved from bit vector */
+int16_t bitvec_get_int16_msb(const struct bitvec *bv, unsigned int num_bits)
+{
+	if (num_bits > 15 || bv->cur_bit < num_bits)
+		return -EINVAL;
+
+	if (num_bits < 9)
+		return bv->data[0] >> (8 - num_bits);
+
+	return osmo_load16be(bv->data) >> (16 - num_bits);
+}
+
+/*! get multiple bits (based on numeric value) from current pos
+ *  \return integer value retrieved from bit vector */
+int bitvec_get_uint(struct bitvec *bv, unsigned int num_bits)
+{
+	int i;
+	unsigned int ui = 0;
+
+	for (i = 0; i < num_bits; i++) {
+		int bit = bitvec_get_bit_pos(bv, bv->cur_bit);
+		if (bit < 0)
+			return bit;
+		if (bit)
+			ui |= (1 << (num_bits - i - 1));
+		bv->cur_bit++;
+	}
+
+	return ui;
+}
+
+/*! fill num_bits with \fill starting from the current position
+ *  \return 0 on success; negative otherwise (out of vector boundary)
+ */
+int bitvec_fill(struct bitvec *bv, unsigned int num_bits, enum bit_value fill)
+{
+	unsigned i, stop = bv->cur_bit + num_bits;
+	for (i = bv->cur_bit; i < stop; i++)
+		if (bitvec_set_bit(bv, fill) < 0)
+			return -EINVAL;
+
+	return 0;
+}
+
+/*! pad all remaining bits up to num_bits
+ *  \return 0 on success; negative otherwise */
+int bitvec_spare_padding(struct bitvec *bv, unsigned int up_to_bit)
+{
+	int n = up_to_bit - bv->cur_bit + 1;
+	if (n < 1)
+		return 0;
+
+	return bitvec_fill(bv, n, L);
+}
+
+/*! find first bit set in bit vector
+ *  \return 0 on success; negative otherwise */
+int bitvec_find_bit_pos(const struct bitvec *bv, unsigned int n,
+			enum bit_value val)
+{
+	unsigned int i;
+
+	for (i = n; i < bv->data_len*8; i++) {
+		if (bitvec_get_bit_pos(bv, i) == val)
+			return i;
+	}
+
+	return -1;
+}
+
+/*! get multiple bytes from current pos
+ *  Assumes MSB first encoding.
+ *  \param[in] bv bit vector
+ *  \param[in] bytes array
+ *  \param[in] count number of bytes to copy
+ *  \return 0 on success; negative otherwise
+ */
+int bitvec_get_bytes(struct bitvec *bv, uint8_t *bytes, unsigned int count)
+{
+	int byte_offs = bytenum_from_bitnum(bv->cur_bit);
+	int bit_offs = bv->cur_bit % 8;
+	uint8_t c, last_c;
+	int i;
+	uint8_t *src;
+
+	if (byte_offs + count + (bit_offs ? 1 : 0) > bv->data_len)
+		return -EINVAL;
+
+	if (bit_offs == 0) {
+		memcpy(bytes, bv->data + byte_offs, count);
+	} else {
+		src = bv->data + byte_offs;
+		last_c = *(src++);
+		for (i = count; i > 0; i--) {
+			c = *(src++);
+			*(bytes++) =
+				(last_c << bit_offs) |
+				(c >> (8 - bit_offs));
+			last_c = c;
+		}
+	}
+
+	bv->cur_bit += count * 8;
+	return 0;
+}
+
+/*! set multiple bytes at current pos
+ *  Assumes MSB first encoding.
+ *  \param[in] bv bit vector
+ *  \param[in] bytes array
+ *  \param[in] count number of bytes to copy
+ *  \return 0 on success; negative otherwise
+ */
+int bitvec_set_bytes(struct bitvec *bv, const uint8_t *bytes, unsigned int count)
+{
+	int byte_offs = bytenum_from_bitnum(bv->cur_bit);
+	int bit_offs = bv->cur_bit % 8;
+	uint8_t c, last_c;
+	int i;
+	uint8_t *dst;
+
+	if (byte_offs + count + (bit_offs ? 1 : 0) > bv->data_len)
+		return -EINVAL;
+
+	if (bit_offs == 0) {
+		memcpy(bv->data + byte_offs, bytes, count);
+	} else if (count > 0) {
+		dst = bv->data + byte_offs;
+		/* Get lower bits of first dst byte */
+		last_c = *dst >> (8 - bit_offs);
+		for (i = count; i > 0; i--) {
+			c = *(bytes++);
+			*(dst++) =
+				(last_c << (8 - bit_offs)) |
+				(c >> bit_offs);
+			last_c = c;
+		}
+		/* Overwrite lower bits of N+1 dst byte */
+		*dst = (*dst & ((1 << (8 - bit_offs)) - 1)) |
+			(last_c << (8 - bit_offs));
+	}
+
+	bv->cur_bit += count * 8;
+	return 0;
+}
+
+/*! Allocate a bit vector
+ *  \param[in] size Number of bits in the vector
+ *  \param[in] ctx Context from which to allocate
+ *  \return pointer to allocated vector; NULL in case of error /
+struct bitvec *bitvec_alloc(unsigned int size, TALLOC_CTX *ctx)
+{
+	struct bitvec *bv = talloc_zero(ctx, struct bitvec);
+	if (!bv)
+		return NULL;
+
+	bv->data = talloc_zero_array(bv, uint8_t, size);
+	if (!(bv->data)) {
+		talloc_free(bv);
+		return NULL;
+	}
+
+	bv->data_len = size;
+	bv->cur_bit = 0;
+	return bv;
+}
+
+/*! Free a bit vector (release its memory)
+ *  \param[in] bit vector to free *
+void bitvec_free(struct bitvec *bv)
+{
+	talloc_free(bv->data);
+	talloc_free(bv);
+}
+*/
+/*! Export a bit vector to a buffer
+ *  \param[in] bitvec (unpacked bits)
+ *  \param[out] buffer for the unpacked bits
+ *  \return number of bytes (= bits) copied */
+unsigned int bitvec_pack(const struct bitvec *bv, uint8_t *buffer)
+{
+	unsigned int i = 0;
+	for (i = 0; i < bv->data_len; i++)
+		buffer[i] = bv->data[i];
+
+	return i;
+}
+
+/*! Copy buffer of unpacked bits into bit vector
+ *  \param[in] buffer unpacked input bits
+ *  \param[out] bv unpacked bit vector
+ *  \return number of bytes (= bits) copied */
+unsigned int bitvec_unpack(struct bitvec *bv, const uint8_t *buffer)
+{
+	unsigned int i = 0;
+	for (i = 0; i < bv->data_len; i++)
+		bv->data[i] = buffer[i];
+
+	return i;
+}
+
+/*! read hexadecimap string into a bit vector
+ *  \param[in] src string containing hex digits
+ *  \param[out] bv unpacked bit vector
+ *  \return 0 in case of success; 1 in case of error
+ */
+int bitvec_unhex(struct bitvec *bv, const char *src)
+{
+	unsigned i;
+	unsigned val;
+	unsigned write_index = 0;
+	unsigned digits = bv->data_len * 2;
+
+	for (i = 0; i < digits; i++) {
+		if (sscanf(src + i, "%1x", &val) < 1) {
+			return 1;
+		}
+		bitvec_write_field(bv, &write_index, val, 4);
+	}
+	return 0;
+}
+
+/*! read part of the vector
+ *  \param[in] bv The boolean vector to work on
+ *  \param[in,out] read_index Where reading supposed to start in the vector
+ *  \param[in] len How many bits to read from vector
+ *  \returns read bits or negative value on error
+ */
+uint64_t bitvec_read_field(struct bitvec *bv, unsigned int *read_index, unsigned int len)
+{
+	unsigned int i;
+	uint64_t ui = 0;
+	bv->cur_bit = *read_index;
+
+	for (i = 0; i < len; i++) {
+		int bit = bitvec_get_bit_pos((const struct bitvec *)bv, bv->cur_bit);
+		if (bit < 0)
+			return bit;
+		if (bit)
+			ui |= ((uint64_t)1 << (len - i - 1));
+		bv->cur_bit++;
+	}
+	*read_index += len;
+	return ui;
+}
+
+/*! write into the vector
+ *  \param[in] bv The boolean vector to work on
+ *  \param[in,out] write_index Where writing supposed to start in the vector
+ *  \param[in] len How many bits to write
+ *  \returns next write index or negative value on error
+ */
+int bitvec_write_field(struct bitvec *bv, unsigned int *write_index, uint64_t val, unsigned int len)
+{
+	int rc;
+
+	bv->cur_bit = *write_index;
+
+	rc = bitvec_set_u64(bv, val, len, false);
+	if (rc != 0)
+		return rc;
+
+	*write_index += len;
+
+	return 0;
+}
+
+/*! convert enum to corresponding character
+ *  \param v input value (bit)
+ *  \return single character, either 0, 1, L or H */
+char bit_value_to_char(enum bit_value v)
+{
+	switch (v) {
+	case ZERO: return '0';
+	case ONE: return '1';
+	case L: return 'L';
+	case H: return 'H';
+	default: abort();
+	}
+}
+
+/*! prints bit vector to provided string
+ * It's caller's responsibility to ensure that we won't shoot him in the foot:
+ * the provided buffer should be at lest cur_bit + 1 bytes long
+ */
+void bitvec_to_string_r(const struct bitvec *bv, char *str)
+{
+	unsigned i, pos = 0;
+	char *cur = str;
+	for (i = 0; i < bv->cur_bit; i++) {
+		if (0 == i % 8)
+			*cur++ = ' ';
+		*cur++ = bit_value_to_char(bitvec_get_bit_pos(bv, i));
+		pos++;
+	}
+	*cur = 0;
+}
+
+/* we assume that x have at least 1 non-b bit */
+static inline unsigned leading_bits(uint8_t x, bool b)
+{
+	if (b) {
+		if (x < 0x80) return 0;
+		if (x < 0xC0) return 1;
+		if (x < 0xE0) return 2;
+		if (x < 0xF0) return 3;
+		if (x < 0xF8) return 4;
+		if (x < 0xFC) return 5;
+		if (x < 0xFE) return 6;
+	} else {
+		if (x > 0x7F) return 0;
+		if (x > 0x3F) return 1;
+		if (x > 0x1F) return 2;
+		if (x > 0xF) return 3;
+		if (x > 7) return 4;
+		if (x > 3) return 5;
+		if (x > 1) return 6;
+	}
+	return 7;
+}
+/*! force bit vector to all 0 and current bit to the beginnig of the vector */
+void bitvec_zero(struct bitvec *bv)
+{
+	bv->cur_bit = 0;
+	memset(bv->data, 0, bv->data_len);
+}
+
+/*! Return number (bits) of uninterrupted bit run in vector starting from the MSB
+ *  \param[in] bv The boolean vector to work on
+ *  \param[in] b The boolean, sequence of which is looked at from the vector start
+ *  \returns Number of consecutive bits of \p b in \p bv
+ */
+unsigned bitvec_rl(const struct bitvec *bv, bool b)
+{
+	unsigned i;
+	for (i = 0; i < (bv->cur_bit % 8 ? bv->cur_bit / 8 + 1 : bv->cur_bit / 8); i++) {
+		if ( (b ? 0xFF : 0) != bv->data[i])
+			return i * 8 + leading_bits(bv->data[i], b);
+	}
+
+	return bv->cur_bit;
+}
+
+/*! Return number (bits) of uninterrupted bit run in vector
+ *   starting from the current bit
+ *  \param[in] bv The boolean vector to work on
+ *  \param[in] b The boolean, sequence of 1's or 0's to be checked
+ *  \param[in] max_bits Total Number of Uncmopresed bits
+ *  \returns Number of consecutive bits of \p b in \p bv and cur_bit will
+ *  \go to cur_bit + number of consecutive bit
+ */
+unsigned bitvec_rl_curbit(struct bitvec *bv, bool b, int max_bits)
+{
+	unsigned i = 0;
+	unsigned j = 8;
+	int temp_res = 0;
+	int count = 0;
+	unsigned readIndex = bv->cur_bit;
+	unsigned remaining_bits = max_bits % 8;
+	unsigned remaining_bytes = max_bits / 8;
+	unsigned byte_mask = 0xFF;
+
+	if (readIndex % 8) {
+		for (j -= (readIndex % 8) ; j > 0 ; j--) {
+			if (readIndex < max_bits && bitvec_read_field(bv, &readIndex, 1) == b)
+				temp_res++;
+			else {
+				bv->cur_bit--;
+				return temp_res;
+			}
+		}
+	}
+	for (i = (readIndex / 8);
+			i < (remaining_bits ? remaining_bytes + 1 : remaining_bytes);
+			i++, count++) {
+		if ((b ? byte_mask : 0) != bv->data[i]) {
+			bv->cur_bit = (count * 8 +
+					leading_bits(bv->data[i], b) + readIndex);
+			return count * 8 +
+				leading_bits(bv->data[i], b) + temp_res;
+		}
+	}
+	bv->cur_bit = (temp_res + (count * 8)) + readIndex;
+	if (bv->cur_bit > max_bits)
+		bv->cur_bit = max_bits;
+	return (bv->cur_bit - readIndex + temp_res);
+}
+
+/*! Shifts bitvec to the left, n MSB bits lost */
+void bitvec_shiftl(struct bitvec *bv, unsigned n)
+{
+	if (0 == n)
+		return;
+	if (n >= bv->cur_bit) {
+		bitvec_zero(bv);
+		return;
+	}
+
+	memmove(bv->data, bv->data + n / 8, bv->data_len - n / 8);
+
+	uint8_t tmp[2];
+	unsigned i;
+	for (i = 0; i < bv->data_len - 2; i++) {
+		uint16_t t = osmo_load16be(bv->data + i);
+		osmo_store16be(t << (n % 8), &tmp);
+		bv->data[i] = tmp[0];
+	}
+
+	bv->data[bv->data_len - 1] <<= (n % 8);
+	bv->cur_bit -= n;
+}
+
+/*! Add given array to bitvec
+ *  \param[in,out] bv bit vector to work with
+ *  \param[in] array elements to be added
+ *  \param[in] array_len length of array
+ *  \param[in] dry_run indicates whether to return number of bits required
+ *  instead of adding anything to bv for real
+ *  \param[in] num_bits number of bits to consider in each element of array
+ *  \returns number of bits necessary to add array elements if dry_run is true,
+ *  0 otherwise (only in this case bv is actually changed)
+ *
+ * N. B: no length checks are performed on bv - it's caller's job to ensure
+ * enough space is available - for example by calling with dry_run = true first.
+ *
+ * Useful for common pattern in CSN.1 spec which looks like:
+ * { 1 < XXX : bit (num_bits) > } ** 0
+ * which means repeat any times (between 0 and infinity),
+ * start each repetition with 1, mark end of repetitions with 0 bit
+ * see app. note in 3GPP TS 24.007 § B.2.1 Rule A2
+ */
+unsigned int bitvec_add_array(struct bitvec *bv, const uint32_t *array,
+			      unsigned int array_len, bool dry_run,
+			      unsigned int num_bits)
+{
+	unsigned i, bits = 1; /* account for stop bit */
+	for (i = 0; i < array_len; i++) {
+		if (dry_run) {
+			bits += (1 + num_bits);
+		} else {
+			bitvec_set_bit(bv, 1);
+			bitvec_set_uint(bv, array[i], num_bits);
+		}
+	}
+
+	if (dry_run)
+		return bits;
+
+	bitvec_set_bit(bv, 0); /* stop bit - end of the sequence */
+	return 0;
+}
+
+/*! @} */