openblt_usb.cpp

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#include "pch.h"
#include "usbcfg.h"
#include "usbconsole.h"
 
extern "C" {
    #include "boot.h"
    #include "rs232.h"
}
 
extern blt_bool stayInBootloader;
 
void Rs232Init() {
#if (BOOT_BACKDOOR_ENTRY_TIMEOUT_MS == 0)
    if (stayInBootloader || (NvmVerifyChecksum() == BLT_FALSE))
#endif
    {
      // Set up USB serial
    usb_serial_start();
    }
}
 
#define RS232_CTO_RX_PACKET_TIMEOUT_MS (100u)
 
static blt_bool Rs232ReceiveByte(blt_int8u *data);
static void     Rs232TransmitByte(blt_int8u data);
 
/************************************************************************************//**
** \brief     Transmits a packet formatted for the communication interface.
** \param     data Pointer to byte array with data that it to be transmitted.
** \param     len  Number of bytes that are to be transmitted.
** \return    none.
**
****************************************************************************************/
void Rs232TransmitPacket(blt_int8u *data, blt_int8u len)
{
 
  /* verify validity of the len-paramenter */
  // ASSERT_RT(len <= BOOT_COM_RS232_TX_MAX_DATA);
 
  /* first transmit the length of the packet */
  Rs232TransmitByte(len);
 
  chnWriteTimeout(&SDU1, data, len, TIME_INFINITE);
 
  /* wait for transmission ends */
  usb_serial_flush();
} /*** end of Rs232TransmitPacket ***/
 
PUBLIC_API_WEAK void openBltUnexpectedByte(blt_int8u firstByte) {
#if defined(OPEN_BLT_TEST_COMMAND)
// 'z' is right at the end of 128 ascii range
static_assert(BOOT_COM_RS232_RX_MAX_DATA < 'z');
  if (firstByte == 'z') {
  const char * bltTest = "openblt\n";
    chnWriteTimeout(&SDU1, (const uint8_t*)bltTest, sizeof(bltTest), TIME_INFINITE);
  }
#endif // OPEN_BLT_TEST_COMMAND
}
 
/************************************************************************************//**
** \brief     Receives a communication interface packet if one is present.
** \param     data Pointer to byte array where the data is to be stored.
** \param     len Pointer where the length of the packet is to be stored.
** \return    BLT_TRUE if a packet was received, BLT_FALSE otherwise.
**
****************************************************************************************/
blt_bool Rs232ReceivePacket(blt_int8u *data, blt_int8u *len)
{
  static blt_int8u xcpCtoReqPacket[BOOT_COM_RS232_RX_MAX_DATA+1];  /* one extra for length */
  static blt_int8u xcpCtoRxLength;
  static blt_bool  xcpCtoRxInProgress = BLT_FALSE;
  static blt_int32u xcpCtoRxStartTime = 0;
 
  /* start of cto packet received? */
  if (xcpCtoRxInProgress == BLT_FALSE)
  {
    /* store the message length when received */
    if (Rs232ReceiveByte(&xcpCtoReqPacket[0]) == BLT_TRUE)
    {
      if ( (xcpCtoReqPacket[0] > 0) &&
           (xcpCtoReqPacket[0] <= BOOT_COM_RS232_RX_MAX_DATA) )
      {
        /* store the start time */
        xcpCtoRxStartTime = TimerGet();
        /* reset packet data count */
        xcpCtoRxLength = 0;
        /* indicate that a cto packet is being received */
        xcpCtoRxInProgress = BLT_TRUE;
      } else {
        openBltUnexpectedByte(xcpCtoReqPacket[0]);
      }
    }
  }
  else
  {
    /* store the next packet byte */
    if (Rs232ReceiveByte(&xcpCtoReqPacket[xcpCtoRxLength+1]) == BLT_TRUE)
    {
      /* increment the packet data count */
      xcpCtoRxLength++;
 
      /* check to see if the entire packet was received */
      if (xcpCtoRxLength == xcpCtoReqPacket[0])
      {
        /* copy the packet data */
        CpuMemCopy((blt_int32u)data, (blt_int32u)&xcpCtoReqPacket[1], xcpCtoRxLength);
        /* done with cto packet reception */
        xcpCtoRxInProgress = BLT_FALSE;
        /* set the packet length */
        *len = xcpCtoRxLength;
        /* packet reception complete */
        return BLT_TRUE;
      }
    }
    else
    {
      /* check packet reception timeout */
      if (TimerGet() > (xcpCtoRxStartTime + RS232_CTO_RX_PACKET_TIMEOUT_MS))
      {
        /* cancel cto packet reception due to timeout. note that that automaticaly
         * discards the already received packet bytes, allowing the host to retry.
         */
        xcpCtoRxInProgress = BLT_FALSE;
      }
    }
  }
  /* packet reception not yet complete */
  return BLT_FALSE;
} /*** end of Rs232ReceivePacket ***/
 
static blt_bool Rs232ReceiveByte(blt_int8u *data)
{
    if (!is_usb_serial_ready()) {
        return BLT_FALSE;
    }
 
    auto bytesRead = chnReadTimeout(&SDU1, data, 1, TIME_IMMEDIATE);
 
    return bytesRead == 0 ? BLT_FALSE : BLT_TRUE;
}
 
static void Rs232TransmitByte(blt_int8u data)
{
    chnWriteTimeout(&SDU1, &data, 1, TIME_INFINITE);
}