Harald Welte | 2230c13 | 2011-01-19 10:10:16 +0100 | [diff] [blame] | 1 | #ifndef _OSMO_BITS_H |
| 2 | #define _OSMO_BITS_H |
| 3 | |
| 4 | #include <stdint.h> |
| 5 | |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 6 | /*! \defgroup bits soft, unpacked and packed bits |
| 7 | * @{ |
| 8 | */ |
| 9 | |
Harald Welte | bd598e3 | 2011-08-16 23:26:52 +0200 | [diff] [blame] | 10 | /*! \file bits.h |
| 11 | * \brief Osmocom bit level support code |
| 12 | */ |
| 13 | |
| 14 | typedef int8_t sbit_t; /*!< \brief soft bit (-127...127) */ |
| 15 | typedef uint8_t ubit_t; /*!< \brief unpacked bit (0 or 1) */ |
| 16 | typedef uint8_t pbit_t; /*!< \brief packed bis (8 bits in a byte) */ |
Harald Welte | 2230c13 | 2011-01-19 10:10:16 +0100 | [diff] [blame] | 17 | |
Christian Vogel | c7f84e9 | 2011-01-22 22:48:37 +0100 | [diff] [blame] | 18 | /* |
| 19 | NOTE on the endianess of pbit_t: |
| 20 | Bits in a pbit_t are ordered MSB first, i.e. 0x80 is the first bit. |
| 21 | Bit i in a pbit_t array is array[i/8] & (1<<(7-i%8)) |
| 22 | */ |
| 23 | |
Harald Welte | bd598e3 | 2011-08-16 23:26:52 +0200 | [diff] [blame] | 24 | /*! \brief determine how many bytes we would need for \a num_bits packed bits |
| 25 | * \param[in] num_bits Number of packed bits |
| 26 | */ |
Harald Welte | 2230c13 | 2011-01-19 10:10:16 +0100 | [diff] [blame] | 27 | static inline unsigned int osmo_pbit_bytesize(unsigned int num_bits) |
| 28 | { |
| 29 | unsigned int pbit_bytesize = num_bits / 8; |
| 30 | |
| 31 | if (num_bits % 8) |
| 32 | pbit_bytesize++; |
| 33 | |
| 34 | return pbit_bytesize; |
| 35 | } |
| 36 | |
Harald Welte | 2230c13 | 2011-01-19 10:10:16 +0100 | [diff] [blame] | 37 | int osmo_ubit2pbit(pbit_t *out, const ubit_t *in, unsigned int num_bits); |
| 38 | |
Harald Welte | 2230c13 | 2011-01-19 10:10:16 +0100 | [diff] [blame] | 39 | int osmo_pbit2ubit(ubit_t *out, const pbit_t *in, unsigned int num_bits); |
| 40 | |
Sylvain Munaut | aeb1077 | 2011-01-21 12:22:30 +0100 | [diff] [blame] | 41 | int osmo_ubit2pbit_ext(pbit_t *out, unsigned int out_ofs, |
| 42 | const ubit_t *in, unsigned int in_ofs, |
| 43 | unsigned int num_bits, int lsb_mode); |
| 44 | |
Sylvain Munaut | aeb1077 | 2011-01-21 12:22:30 +0100 | [diff] [blame] | 45 | int osmo_pbit2ubit_ext(ubit_t *out, unsigned int out_ofs, |
| 46 | const pbit_t *in, unsigned int in_ofs, |
| 47 | unsigned int num_bits, int lsb_mode); |
| 48 | |
Harald Welte | 712691d | 2011-09-01 14:47:31 +0200 | [diff] [blame] | 49 | |
| 50 | /* BIT REVERSAL */ |
| 51 | |
| 52 | /*! \brief bit-reversal mode for osmo_bit_reversal() */ |
| 53 | enum osmo_br_mode { |
| 54 | /*! \brief reverse all bits in a 32bit dword */ |
| 55 | OSMO_BR_BITS_IN_DWORD = 31, |
| 56 | /*! \brief reverse byte order in a 32bit dword */ |
| 57 | OSMO_BR_BYTES_IN_DWORD = 24, |
| 58 | /*! \brief reverse bits of each byte in a 32bit dword */ |
| 59 | OSMO_BR_BITS_IN_BYTE = 7, |
| 60 | /*! \brief swap the two 16bit words in a 32bit dword */ |
| 61 | OSMO_BR_WORD_SWAP = 16, |
| 62 | }; |
| 63 | |
| 64 | /*! \brief generic bit reversal function */ |
| 65 | uint32_t osmo_bit_reversal(uint32_t x, enum osmo_br_mode k); |
| 66 | |
| 67 | /* \brief reverse the bits within each byte of a 32bit word */ |
| 68 | uint32_t osmo_revbytebits_32(uint32_t x); |
| 69 | |
| 70 | /* \brief reverse the bits within a byte */ |
| 71 | uint32_t osmo_revbytebits_8(uint8_t x); |
| 72 | |
| 73 | /* \brief reverse the bits of each byte in a given buffer */ |
| 74 | void osmo_revbytebits_buf(uint8_t *buf, int len); |
| 75 | |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 76 | /*! }@ */ |
| 77 | |
| 78 | #endif /* _OSMO_BITS_H */ |