WIP: More work on SuperChannel decode, but it doesn't work yet...
This commit is contained in:
parent
59b94d0611
commit
d83c51379b
|
@ -0,0 +1,29 @@
|
|||
#include <stdint.h>
|
||||
#include "flip_bits.h"
|
||||
|
||||
static uint8_t flip_table[256];
|
||||
|
||||
void init_flip_bits(void)
|
||||
{
|
||||
int i,k;
|
||||
|
||||
for (i = 0 ; i < 256 ; i++) {
|
||||
uint8_t sample = 0 ;
|
||||
for (k = 0; k<8; k++) {
|
||||
if ( i & 1 << k ) sample |= 0x80 >> k;
|
||||
}
|
||||
flip_table[i] = sample;
|
||||
}
|
||||
}
|
||||
|
||||
uint8_t *flip_buf_bits(uint8_t *buf, int len)
|
||||
{
|
||||
int i;
|
||||
uint8_t *start = buf;
|
||||
|
||||
for (i = 0 ; i < len; i++) {
|
||||
buf[i] = flip_table[(uint8_t)buf[i]];
|
||||
}
|
||||
|
||||
return start;
|
||||
}
|
|
@ -0,0 +1,4 @@
|
|||
#pragma once
|
||||
|
||||
void init_flip_bits(void);
|
||||
uint8_t *flip_buf_bits(uint8_t * buf , int len);
|
|
@ -0,0 +1,111 @@
|
|||
#include <stdint.h>
|
||||
#include <stdio.h>
|
||||
#include <stdlib.h>
|
||||
#include <string.h>
|
||||
|
||||
#include <sys/types.h>
|
||||
#include <sys/stat.h>
|
||||
#include <fcntl.h>
|
||||
|
||||
#include <osmocom/core/utils.h>
|
||||
#include <osmocom/core/bits.h>
|
||||
|
||||
#include "hdlc.h"
|
||||
|
||||
#if 0
|
||||
#define DEBUGP(x, args ...) fprintf(stderr, x, ## args)
|
||||
#else
|
||||
#define DEBUGP(x, args ...) do {} while (0)
|
||||
#endif
|
||||
|
||||
static const ubit_t five_ones[] = { 1,1,1,1,1 };
|
||||
|
||||
static int append_bit(struct hdlc_proc *hdlc, uint8_t bit, int ignore)
|
||||
{
|
||||
memmove(hdlc->history+1, hdlc->history, sizeof(hdlc->history)-1);
|
||||
hdlc->history[0] = bit;
|
||||
if (ignore)
|
||||
return -1;
|
||||
|
||||
memmove(hdlc->next_outbyte+1, hdlc->next_outbyte, sizeof(hdlc->next_outbyte)-1);
|
||||
hdlc->next_outbyte[0] = bit;
|
||||
hdlc->num_bits++;
|
||||
|
||||
if (hdlc->num_bits == 8) {
|
||||
pbit_t out;
|
||||
/* generate one output byte */
|
||||
osmo_ubit2pbit_ext(&out, 0, hdlc->next_outbyte, 0, 8, 0);
|
||||
hdlc->num_bits = 0;
|
||||
return out;
|
||||
}
|
||||
|
||||
return -1;
|
||||
}
|
||||
|
||||
static int process_hdlc_bit(struct hdlc_proc *hdlc, uint8_t bit)
|
||||
{
|
||||
int ignore = 0;
|
||||
int out, flag = 0;
|
||||
|
||||
DEBUGP("bit=%u, history_in = %s, ", bit, osmo_ubit_dump(hdlc->history, sizeof(hdlc->history)));
|
||||
|
||||
switch (hdlc->state) {
|
||||
case STATE_FLAG_WAIT_ZERO:
|
||||
if (bit == 0) {
|
||||
DEBUGP("F ");
|
||||
flag = 1;
|
||||
hdlc->state = STATE_PAYLOAD;
|
||||
} else {
|
||||
hdlc->state = STATE_INIT;
|
||||
}
|
||||
ignore = 1;
|
||||
hdlc->num_bits = 0;
|
||||
break;
|
||||
default:
|
||||
if (!memcmp(five_ones, hdlc->history, sizeof(five_ones))) {
|
||||
if (bit == 1) {
|
||||
//DEBUGP("F ");
|
||||
hdlc->state = STATE_FLAG_WAIT_ZERO;
|
||||
ignore = 1;
|
||||
} else {
|
||||
/* discard bit */
|
||||
ignore = 1;
|
||||
}
|
||||
}
|
||||
break;
|
||||
}
|
||||
out = append_bit(hdlc, bit, ignore);
|
||||
DEBUGP("history_out = %s", osmo_ubit_dump(hdlc->history, sizeof(hdlc->history)));
|
||||
if (out > 0)
|
||||
DEBUGP(", out 0x%02x\n", out);
|
||||
else
|
||||
DEBUGP("\n");
|
||||
|
||||
if (flag)
|
||||
return -123;
|
||||
else
|
||||
return out;
|
||||
}
|
||||
|
||||
int process_raw_hdlc(struct hdlc_proc *hdlc, uint8_t *data, unsigned int len)
|
||||
{
|
||||
unsigned int i;
|
||||
int out;
|
||||
static int last_out;
|
||||
|
||||
for (i = 0; i < len; i ++) {
|
||||
out = process_hdlc_bit(hdlc, data[i]);
|
||||
if (out == -123) {
|
||||
/* suppress repeating Flag characters */
|
||||
if (last_out != out)
|
||||
printf("\nF ");
|
||||
last_out = out;
|
||||
} else if (out >= 0) {
|
||||
/* suppress 0xAA and 0x55 bit pattern */
|
||||
if (out != 0xaa && out != 0x55)
|
||||
printf("%02x ", out);
|
||||
last_out = out;
|
||||
}
|
||||
}
|
||||
return 0;
|
||||
}
|
|
@ -0,0 +1,18 @@
|
|||
#pragma once
|
||||
|
||||
#include <osmocom/core/bits.h>
|
||||
|
||||
enum hdlc_proc_state {
|
||||
STATE_INIT,
|
||||
STATE_FLAG_WAIT_ZERO,
|
||||
STATE_PAYLOAD,
|
||||
};
|
||||
|
||||
struct hdlc_proc {
|
||||
ubit_t history[8];
|
||||
ubit_t next_outbyte[8];
|
||||
enum hdlc_proc_state state;
|
||||
uint8_t num_bits;
|
||||
};
|
||||
|
||||
int process_raw_hdlc(struct hdlc_proc *hdlc, uint8_t *data, unsigned int len);
|
Loading…
Reference in New Issue