Temporary hack to make rs232bus read() work until devices learn to do packets (#1066)

* Temporary hack to make rs232bus read() work until devices learn to do packets
* Fix a bunch of problems with packet decoding

Author: FozzTexx

lib/bus/rs232/FujiBusPacket.cpp

@@ -114,6 +114,9 @@ bool FujiBusPacket::parse(const std::string &input)
     if (decoded.size() < sizeof(fujibus_header))
         return false;
     hdr = (fujibus_header *) &decoded[0];
+    Debug_printv("Header: dev:%02x cmd:%02x len:%d chk:%02x fld:%02x",
+                 hdr->device, hdr->command, hdr->length, hdr->checksum, hdr->fields);
+
     if (hdr->length != decoded.size())
         return false;
 
@@ -131,7 +134,8 @@ bool FujiBusPacket::parse(const std::string &input)
     fieldCount = numFieldsTable[hdr->fields & FUJI_FIELD_COUNT_MASK];
     if (fieldCount)
     {
-        _fieldSize = fieldSizeTable[fieldCount];
+        _fieldSize = fieldSizeTable[hdr->fields & FUJI_FIELD_COUNT_MASK];
+
         for (idx = 0; idx < fieldCount; idx++)
         {
             for (val = jdx = 0; jdx < _fieldSize; jdx++)
@@ -161,6 +165,7 @@ std::string FujiBusPacket::serialize()
     hdr.command = _command;
     hdr.length = sizeof(hdr);
     hdr.checksum = 0;
+    hdr.fields = 0;
 
     std::string output(sizeof(hdr), '\0');
 

lib/bus/rs232/FujiBusPacket.h

@@ -42,6 +42,7 @@ class FujiBusPacket
     fujiDeviceID_t device() { return _device; }
     fujiCommandID_t command() { return _command; }
     unsigned int param(unsigned int index) { return _params[index]; }
+    unsigned int paramCount() { return _params.size(); }
     std::optional<std::string> data() const { return _data; }
 };
 

lib/bus/rs232/rs232.cpp

@@ -97,6 +97,7 @@ void virtualDevice::bus_to_computer(uint8_t *buf, uint16_t len, bool err)
    len = length
    Returns checksum
 */
+#ifdef OBSOLETE
 uint8_t virtualDevice::bus_to_peripheral(uint8_t *buf, unsigned short len)
 {
     // Retrieve data frame from computer
@@ -130,13 +131,27 @@ uint8_t virtualDevice::bus_to_peripheral(uint8_t *buf, unsigned short len)
 
     return ck_rcv;
 }
+#else
+uint8_t virtualDevice::bus_to_peripheral(uint8_t *buf, unsigned short len)
+{
+    // FIXME - This is a terrible hack to allow devices to continue
+    // directly read/write the bus instead of upgrading them to work
+    // with packets.
+    size_t rlen = SYSTEM_BUS.read(buf, len);
+    return rs232_checksum(buf, rlen);
+}
+#endif /* OBSOLETE */
 
 // RS232 NAK
 void virtualDevice::rs232_nak()
 {
+#ifdef OBSOLETE
     SYSTEM_BUS.write('N');
     SYSTEM_BUS.flushOutput();
     Debug_println("NAK!");
+#else
+    rs232_error();
+#endif /* OBSOLETE */
 }
 
 // RS232 ACK
@@ -165,10 +180,13 @@ void virtualDevice::rs232_complete()
 // RS232 ERROR
 void virtualDevice::rs232_error()
 {
-    abort();
+#ifdef OBSOLETE
     fnSystem.delay_microseconds(DELAY_T5);
     SYSTEM_BUS.write('E');
     Debug_println("ERROR!");
+#else
+    SYSTEM_BUS.sendReplyPacket(_devnum, false, nullptr, 0);
+#endif /* OBSOLETE */
 }
 
 #ifdef OBSOLETE
@@ -219,6 +237,12 @@ void systemBus::_rs232_process_cmd()
                  tempFrame->device(), tempFrame->command(),
                  tempFrame->data() ? tempFrame->data()->size() : -1);
 
+    // FIXME - This is a terrible hack to allow devices to continue
+    // directly read/write the bus instead of upgrading them to work
+    // with packets.
+    _lastPacketReceived = tempFrame.get();
+    _lastReadPosition = 0;
+
     if (tempFrame->device() == FUJI_DEVICEID_DISK && _fujiDev != nullptr
         && _fujiDev->boot_config)
     {
@@ -500,8 +524,20 @@ void systemBus::sendReplyPacket(fujiDeviceID_t source, bool ack, void *data, siz
 /* Convert direct bus access into bus packets? */
 size_t systemBus::read(void *buffer, size_t length)
 {
-    abort();
-    return _port->read(buffer, length);
+    // FIXME - This is a terrible hack to allow devices to continue
+    // directly read/write the bus instead of upgrading them to work
+    // with packets.
+    // Assuming 'data()' returns the optional:
+    auto optional_data = _lastPacketReceived->data();
+
+    if (!optional_data.has_value())
+        return 0;
+
+    size_t avail = optional_data.value().size() - _lastReadPosition;
+    avail = std::min(avail, (size_t) length);
+    memcpy(buffer, optional_data.value().data() + _lastReadPosition, avail);
+    _lastReadPosition += avail;
+    return avail;
 }
 
 size_t systemBus::read()

lib/bus/rs232/rs232.h

@@ -199,6 +199,12 @@ struct rs232_message_t
 class systemBus
 {
 private:
+    // FIXME - DO NOT DO CACHE THE LAST PACKET RECEIVED. This is a
+    // terrible hack to allow devices to continue directly read/write
+    // the bus instead of upgrading them to work with packets.
+    FujiBusPacket *_lastPacketReceived;
+    size_t _lastReadPosition;
+
     std::forward_list<virtualDevice *> _daisyChain;
 
     int _command_frame_counter = 0;

lib/device/rs232/network.cpp

@@ -246,7 +246,10 @@ void rs232Network::rs232_read(uint16_t length)
 
     // And send off to the computer
     bus_to_computer((uint8_t *)receiveBuffer->data(), length, err);
-    receiveBuffer->clear();
+
+    // Remove from receive buffer and shrink.
+    receiveBuffer->erase(0, length);
+    receiveBuffer->shrink_to_fit();
 }
 
 /**
@@ -870,7 +873,12 @@ void rs232Network::rs232_process(FujiBusPacket &packet)
         rs232_write(packet.param(0));
         break;
     case FUJICMD_STATUS:
-        rs232_status(static_cast<FujiStatusReq>(packet.param(0)));
+        {
+            FujiStatusReq reqType = STATUS_NETWORK_CONNERR;
+            if (packet.paramCount() >= 2)
+                reqType = (FujiStatusReq) packet.param(1);
+            rs232_status(reqType);
+        }
         break;
     case FUJICMD_PARSE:
         rs232_ack();