srsLTE/liblte/src/liblte_common.cc

/*******************************************************************************

    Copyright 2014 Ben Wojtowicz

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as published by
    the Free Software Foundation, either version 3 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 Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.

*******************************************************************************

    File: liblte_common.cc

    Description: Contains all the implementations for the LTE common library.

    Revision History
    ----------    -------------    --------------------------------------------
    08/03/2014    Ben Wojtowicz    Created file.
    11/29/2014    Ben Wojtowicz    Added liblte prefix to value_2_bits and
                                   bits_2_value.

*******************************************************************************/

/*******************************************************************************
                              INCLUDES
*******************************************************************************/

#include "liblte_common.h"

/*******************************************************************************
                              DEFINES
*******************************************************************************/


/*******************************************************************************
                              TYPEDEFS
*******************************************************************************/


/*******************************************************************************
                              GLOBAL VARIABLES
*******************************************************************************/


/*******************************************************************************
                              FUNCTIONS
*******************************************************************************/

/*********************************************************************
    Name: liblte_value_2_bits

    Description: Converts a value to a bit string
*********************************************************************/
void liblte_value_2_bits(uint32   value,
                         uint8  **bits,
                         uint32   N_bits)
{
    uint32 i;

    for(i=0; i<N_bits; i++)
    {
        (*bits)[i] = (value >> (N_bits-i-1)) & 0x1;
    }
    *bits += N_bits;
}

/*********************************************************************
    Name: liblte_bits_2_value

    Description: Converts a bit string to a value
*********************************************************************/
uint32 liblte_bits_2_value(uint8  **bits,
                           uint32   N_bits)
{
    uint32 value = 0;
    uint32 i;

    for(i=0; i<N_bits; i++)
    {
        value |= (*bits)[i] << (N_bits-i-1);
    }
    *bits += N_bits;

    return(value);
}

/*********************************************************************
    Name: liblte_pack

    Description: Pack a bit array into a byte array
*********************************************************************/
void liblte_pack(LIBLTE_BIT_MSG_STRUCT  *bits,
                 LIBLTE_BYTE_MSG_STRUCT *bytes)
{
    uint8_t* bit_ptr = bits->msg;
    uint32_t i;

    for(i=0; i<bits->N_bits/8; i++)
    {
        bytes->msg[i] = liblte_bits_2_value(&bit_ptr, 8);
    }
    bytes->N_bytes = bits->N_bits/8;
    if(bits->N_bits%8 > 0)
    {
        bytes->msg[bytes->N_bytes] = liblte_bits_2_value(&bit_ptr, bits->N_bits%8);
        bytes->N_bytes++;
    }
}

/*********************************************************************
    Name: liblte_unpack

    Description: Unpack a byte array into a bit array
*********************************************************************/
void liblte_unpack(LIBLTE_BYTE_MSG_STRUCT *bytes,
                   LIBLTE_BIT_MSG_STRUCT  *bits)
{
    uint8_t *bit_ptr = bits->msg;
    uint32_t i;

    for(i=0; i<bytes->N_bytes; i++)
    {
        liblte_value_2_bits(bytes->msg[i], &bit_ptr, 8);
    }
    bits->N_bits = bytes->N_bytes*8;
}

/*********************************************************************
    Name: liblte_pack

    Description: Pack a bit array into a byte array
*********************************************************************/
void liblte_pack(uint8_t *bits,  uint32_t n_bits, uint8_t *bytes)
{
    uint8_t* bit_ptr = bits;
    uint32_t i;

    for(i=0; i<n_bits/8; i++)
    {
        bytes[i] = liblte_bits_2_value(&bit_ptr, 8);
    }
    if(n_bits%8 > 0)
    {
        bytes[n_bits/8] = liblte_bits_2_value(&bit_ptr, n_bits%8);
    }
}

/*********************************************************************
    Name: liblte_unpack

    Description: Unpack a byte array into a bit array
*********************************************************************/
void liblte_unpack(uint8_t *bytes, uint32_t n_bytes, uint8_t *bits)
{
    uint8_t *bit_ptr = bits;
    uint32_t i;

    for(i=0; i<n_bytes; i++)
    {
        liblte_value_2_bits(bytes[i], &bit_ptr, 8);
    }
}

/*********************************************************************
    Name: liblte_align_up

    Description: Aligns a pointer to a multibyte boundary
*********************************************************************/
void liblte_align_up(uint8_t **ptr, uint32_t align)
{
  while( (uint64_t)(*ptr) % align > 0)
  {
    (*ptr)++;
  }
}

/*********************************************************************
    Name: liblte_align_up_zero

    Description:  Aligns a pointer to a multibyte boundary and zeros
                  bytes skipped
*********************************************************************/
void liblte_align_up_zero(uint8_t **ptr, uint32_t align)
{
  while( (uint64_t)(*ptr) % align > 0)
  {
    **ptr = 0;
    (*ptr)++;
  }
}