// Accepts only a good packet. If the packet is a Ping, the Ping response (ACK) is sent.
// Otherwise, the command is NAK'ed.
static bool RespondToPacket(UsbStream pinger, WireProtocol.WP_Packet inPacket, UInt16 seq)
{
WireProtocol.WP_Packet outPacket = new WireProtocol.WP_Packet();
// Allocate space for any data following the packet
int size = (int)(inPacket.m_size & 0xFFFF);
byte[] buffer = new byte[size];
// Read in the data that came with the packet
if (inPacket.m_size != 0)
{
pinger.Read(buffer, 0, size);
}
// Fill in the blanks of the response packet
outPacket.m_signature = "MSdbgV1"; // Standard target signature
outPacket.m_cmd = inPacket.m_cmd; // Show which command this is a response to
outPacket.m_seq = seq++; // Keep track of the target message sequence number
outPacket.m_seqReply = inPacket.m_seq; // Show which host packet sequence number this is a response to
// If the host packet was a Ping
if (inPacket.m_cmd == WireProtocol.Commands.Ping)
{
byte[] data = new byte[8]; // The Ping has an 8 byte data response
outPacket.m_flags = 0x8003; // Return a low-priority ACK
for (int i = 0; i < 8; i++)
{
data[i] = 0; // Initialize all bytes of the data response to zero
}
data[0] = 1; // This tells the host that we are TinyBooter
data[4] = 2; // This is an innoccuous flag value
WireProtocol.SendPacket(pinger, outPacket, data); // Send response to the Ping
}
else
{
outPacket.m_flags = 0x4003; // Return a low-priority NACK
WireProtocol.SendPacket(pinger, outPacket, new byte[0]); // Signal to the host that we don't know what to do with the command
}
return(true);
}