implemation serial HAL

client.cpp

// Step 4  

// test client
#include <vendor/labworks/serialport/1.0/ISerialPort.h>

using vendor::labworks::serialport::V1_0::ISerialPort;
int main(int argc, char *argv[]) 
{
    android::sp<ISerialPort> ser;

    ser = ISerialPort::getService({);
    if (!ser) {
        std::cout << "Error requesting service handler!" << std::endl;
        return 1;
    }
    
    // TX
    ser->tx('0');
    // RX
    printf("RX: %c\n", ser->rx());

    return 0;
}

ISerialPort.hal

// Step 1

interface ISerialPort {
  oneway tx(uint8_t data);
  rx() generates (uint8_t data);
};

// SerialPort.h - generated by hidl-gen
struct SerialPort : public V1_0::ISerialPort {
  // Methods from ::vendor:: labworks::serialport::V1 0::ISerialPort follow.
  Return<void> tx(uint8_t data) override;
  Return<uint8_t> rx() override;

  // Methods from ::android::hidl::base::V1_0::IBase follow.
};


// SerialPort.cpp - generated by hidl-gen
Return<void> SerialPort::tx(uint8_t data) {
  // TODO implement
  return Void();
}

Return<uint8_t> SerialPort::rx() {
  // TODO implement
  return uint8_t {};
}

manifest. xml

// Step 2
$ cat device/generic/goldfish/manifest. xml

<manifest version="1.0" type="device" target-level="3">
  <hal format="hidl">
    <name>vendor.labworks.serialport</name>
    <transport>hwbinder</transport>
    <version>1.0</version>
    <interface>
        <name>ISerialPort</name>
        <instance>default</instance>
    </interface>
  </hal>
<hal format="hid1">
    <name>android.hardware.drm</name>
    <transport>hwbinder</transport>
...

service.cpp

// Step 3
#include "SerialPort .h"

using vendor::labworks::serialport::implementation::SerialPort;
using android::hardware::configureRpcThreadpool;
using android::hardware::joinRpcThreadpool;

int main()
{
    configureRpcThreadpool(16, true);

    android::sp<SerialPort> serialport = new SerialPort();

    if (serialport->registerAsService() != ::android::OK) {
        ALOG(LOG_ERROR, TAG, “Error registering service!");
        return 1;
    }

    ALOG(LOG_INFO, TAG, "Successfully initialized!");
    joinRpcThreadpool();

    return 0; // should never get here
}