/**************************************************************************************************
* @fn sblPoll
*
* @brief Boot Loader main executive processing.
*
* input parameters
*
* None.
*
* output parameters
*
* None.
*
* @return TRUE if sbCmnd() returns TRUE, indicating that an SB_ENABLE_CMD succeeded;
* FALSE otherwise.
**************************************************************************************************
*/
uint8 sblPoll(void)
{
/* Parse the incoming packet’s header, and verify its FCS. Valid packets are transferred to
* sbCmnd() for further processing. For detailed packet format, please see the document "Serial
* Boot Loader for CC2538".
*/
static uint8 sbFrameId, sbCmd, sbFcs, sbSte = SB_SOF_STATE;
static uint32 sbLen;
static uint32 sbIdx;
uint8 ch, rtrn = FALSE;
while(sbRx(&ch, 1))
{
switch (sbSte)
{
case SB_SOF_STATE:
if (SB_SOF == ch)
{
sbSte = SB_LEN_STATE;
sbIdx = 0;
}
break;
/* this field is kept for backward compatibility of the protocol. */
case SB_LEN_STATE:
/* In case the length is larger than 254, this fields is set to 0xFF,
* and there is an additional 32bit length, located in another location
* in this header.
*/
sbLen = ch;
sbFcs = 0;
sbSte = SB_FRAME_ID_STATE;
break;
case SB_FRAME_ID_STATE:
sbFrameId = ch;
sbSte = SB_CMD_STATE;
break;
case SB_CMD_STATE:
sbCmd = ch;
switch (sbLen)
{
case 0:
sbSte = SB_FCS_STATE;
break;
case 0xFF:
sbSte = SB_LEN1_STATE;
break;
default:
sbSte = SB_DATA_STATE;
break;
}
break;
case SB_LEN1_STATE:
sbLen = ch;
sbSte = SB_LEN2_STATE;
break;
case SB_LEN2_STATE:
sbLen += ch << 8;
sbSte = SB_LEN3_STATE;
break;
case SB_LEN3_STATE:
sbLen += ch << 16;
sbSte = SB_LEN4_STATE;
break;
case SB_LEN4_STATE:
sbLen += ch << 24;
sbSte = (sbLen) ? SB_DATA_STATE : SB_FCS_STATE;
break;
case SB_DATA_STATE:
if (sbIdx >= sizeof(_sbBuf))
{
/* discard this packet. the payload is too long. */
sbSte = SB_SOF_STATE;
}
else
{
sbBuf[sbIdx] = ch;
sbIdx++;
if (sbIdx == sbLen)
{
sbSte = SB_FCS_STATE;
}
}
break;
case SB_FCS_STATE:
if ((sbFcs == ch) && (sbFrameId == SB_RPC_SYS_BOOT))
{
rtrn = sbCmnd(sbCmd, sbLen);
}
sbSte = SB_SOF_STATE;
break;
default:
break;
}
sbFcs ^= ch;
}
return rtrn;
}
/**************************************************************************************************
* @fn sbExec
*
* @brief Boot Loader main executive processing.
*
* input parameters
*
* None.
*
* output parameters
*
* None.
*
* @return TRUE if sbCmnd() returns TRUE, indicating that an SB_ENABLE_CMD succeeded;
* FALSE otherwise.
**************************************************************************************************
*/
uint8 sbExec(void)
{
uint8 ch, rtrn = FALSE;
while (SB_RX(&ch))
{
sbBuf[sbSte + sbIdx] = ch;
switch (sbSte)
{
case SB_SOF_STATE:
if (SB_SOF == ch)
{
sbSte = SB_LEN_STATE;
}
break;
case SB_LEN_STATE:
sbFcs = 0;
sbSte = ((sbLen = ch) >= SB_BUF_SIZE) ? SB_SOF_STATE : SB_CMD1_STATE;
break;
case SB_CMD1_STATE:
sbCmd1 = ch;
sbSte = SB_CMD2_STATE;
break;
case SB_CMD2_STATE:
sbCmd2 = ch;
sbSte = (sbLen) ? SB_DATA_STATE : SB_FCS_STATE;
break;
case SB_DATA_STATE:
if (++sbIdx == sbLen)
{
sbSte = SB_FCS_STATE;
}
break;
case SB_FCS_STATE:
if ((sbFcs == ch) && (sbCmd1 == SB_RPC_SYS_BOOT))
{
rtrn = sbCmnd();
}
else
{
// TODO - RemoTI did not have here or on bad length - adding could cause > 1 SB_INVALID_FCS
// for a single data packet which could put out of sync with PC for awhile or
// infinte, depending on PC-side?
// sbResp(SB_INVALID_FCS, 1);
}
sbSte = sbIdx = 0;
break;
default:
break;
}
sbFcs ^= ch;
}
return rtrn;
}