void proto_packet_seal(struct proto_packet *packet)
{
packet->sof = PROTO_SOF;
packet->crc = crc8_start();
packet->crc = crc8_calc(packet->crc, packet->addr);
packet->crc = crc8_calc(packet->crc, packet->cmd);
packet->crc = crc8_calc(packet->crc, packet->val);
packet->crc = crc8_end(packet->crc);
packet->eof = PROTO_EOF;
}
/*
* Given offset in flash area, fill in rest of the fcb_entry, and crc8 over
* the data.
*/
int
fcb_elem_crc8(struct fcb *fcb, struct fcb_entry *loc, uint8_t *c8p)
{
uint8_t tmp_str[FCB_TMP_BUF_SZ];
int cnt;
int blk_sz;
uint8_t crc8;
uint16_t len;
uint32_t off;
uint32_t end;
int rc;
if (loc->fe_elem_off + 2 > loc->fe_area->fa_size) {
return FCB_ERR_NOVAR;
}
rc = flash_area_read(loc->fe_area, loc->fe_elem_off, tmp_str, 2);
if (rc) {
return FCB_ERR_FLASH;
}
cnt = fcb_get_len(tmp_str, &len);
if (cnt < 0) {
return cnt;
}
loc->fe_data_off = loc->fe_elem_off + fcb_len_in_flash(fcb, cnt);
loc->fe_data_len = len;
crc8 = crc8_init();
crc8 = crc8_calc(crc8, tmp_str, cnt);
off = loc->fe_data_off;
end = loc->fe_data_off + len;
for (; off < end; off += blk_sz) {
blk_sz = end - off;
if (blk_sz > sizeof(tmp_str)) {
blk_sz = sizeof(tmp_str);
}
rc = flash_area_read(loc->fe_area, off, tmp_str, blk_sz);
if (rc) {
return FCB_ERR_FLASH;
}
crc8 = crc8_calc(crc8, tmp_str, blk_sz);
}
*c8p = crc8;
return 0;
}
/**
* @param credits - only used for RFCOMM flow control in UIH wiht P/F = 1
*/
void rfcomm_send_packet(uint16_t source_cid, uint8_t address, uint8_t control, uint8_t credits, uint8_t *data, uint16_t len){
uint16_t pos = 0;
uint8_t crc_fields = 3;
rfcomm_out_buffer[pos++] = address;
rfcomm_out_buffer[pos++] = control;
// length field can be 1 or 2 octets
if (len < 128){
rfcomm_out_buffer[pos++] = (len << 1)| 1; // bits 0-6
} else {
rfcomm_out_buffer[pos++] = (len & 0x7f) << 1; // bits 0-6
rfcomm_out_buffer[pos++] = len >> 7; // bits 7-14
crc_fields++;
}
// add credits for UIH frames when PF bit is set
if (control == BT_RFCOMM_UIH_PF){
rfcomm_out_buffer[pos++] = credits;
}
// copy actual data
memcpy(&rfcomm_out_buffer[pos], data, len);
pos += len;
// UIH frames only calc FCS over address + control (5.1.1)
if ((control & 0xef) == BT_RFCOMM_UIH){
crc_fields = 2;
}
rfcomm_out_buffer[pos++] = crc8_calc(rfcomm_out_buffer, crc_fields); // calc fcs
bt_send_l2cap( source_cid, rfcomm_out_buffer, pos);
}