diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
new file mode 100644
index 0000000..b172482
--- /dev/null
+++ b/.github/workflows/test.yaml
@@ -0,0 +1,92 @@
+name: test
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  create-test-artifacts:
+    runs-on: ubuntu-20.04
+
+    steps:
+      - name: checkout
+        uses: actions/checkout@v1
+        with:
+          fetch-depth: 0
+
+      - name: Install Taskfile
+        uses: arduino/actions/setup-taskfile@master
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          version: 3.x
+
+      - name: Build
+        run: |
+          PACKAGE_NAME_PREFIX="${{ github.workflow }}"
+          if [ "${{ github.event_name }}" = "pull_request" ]; then
+            PACKAGE_NAME_PREFIX="$PACKAGE_NAME_PREFIX-${{ github.event.number }}"
+          fi
+          PACKAGE_NAME_PREFIX="$PACKAGE_NAME_PREFIX-${{ github.sha }}-"
+          export PACKAGE_NAME_PREFIX
+          task dist:all
+
+      # Uploads all architectures as separate artifacts
+      - name: Upload Linux 32 bit artifact
+        uses: actions/upload-artifact@v2
+        with:
+          name: Linux_32bit
+          path: dist/*Linux_32bit.tar.gz
+
+      - name: Upload Linux 64 bit artifact
+        uses: actions/upload-artifact@v2
+        with:
+          name: Linux_64bit
+          path: dist/*Linux_64bit.tar.gz
+
+      - name: Upload Windows 32 bit artifact
+        uses: actions/upload-artifact@v2
+        with:
+          name: Windows_32bit
+          path: dist/*Windows_32bit.zip
+
+      - name: Upload Windows 64 bit artifact
+        uses: actions/upload-artifact@v2
+        with:
+          name: Windows_64bit
+          path: dist/*Windows_64bit.zip
+
+      - name: Upload Linux ARMv6 artifact
+        uses: actions/upload-artifact@v2
+        with:
+          name: Linux_ARMv6
+          path: dist/*Linux_ARMv6.tar.gz
+
+      - name: Upload Linux ARMv7 artifact
+        uses: actions/upload-artifact@v2
+        with:
+          name: Linux_ARMv7
+          path: dist/*Linux_ARMv7.tar.gz
+
+      - name: Upload Linux ARM64 artifact
+        uses: actions/upload-artifact@v2
+        with:
+          name: Linux_ARM64
+          path: dist/*Linux_ARM64.tar.gz
+
+      - name: Upload Linux ARM64 bit artifact
+        uses: actions/upload-artifact@v2
+        with:
+          name: Linux_ARM64
+          path: dist/*Linux_ARM64.tar.gz
+
+      - name: Upload MacOS 64 bit artifact
+        uses: actions/upload-artifact@v2
+        with:
+          name: macOS_64bit
+          path: dist/*macOS_64bit.tar.gz
+
+      - name: Upload checksums
+        uses: actions/upload-artifact@v2
+        with:
+          name: checksums
+          path: dist/*checksums.txt
diff --git a/DistTasks.yml b/DistTasks.yml
new file mode 100644
index 0000000..3534328
--- /dev/null
+++ b/DistTasks.yml
@@ -0,0 +1,211 @@
+version: "3"
+
+# This taskfile is ideally meant to be project agnostic and could be dropped in
+# on other Go projects with minimal or no changes.
+#
+# To use it simply add the following lines to your main taskfile:
+#   includes:
+#     dist: ./DistTasks.yml
+#
+# The following variables must be declared in the including taskfile for the
+# build process to work correctly:
+# * DIST_DIR: the folder that will contain the final binaries and packages
+# * PROJECT_NAME: the name of the project, used in package name
+# * VERSION: the version of the project, used in package name and checksum file
+# * LD_FLAGS: flags used at build time
+#
+# The project MUST contain a LICENSE.txt file in the root folder or packaging will fail.
+
+tasks:
+  all:
+    desc: Build for distribution for all platforms
+    cmds:
+      - task: Windows_32bit
+      - task: Windows_64bit
+      - task: Linux_32bit
+      - task: Linux_64bit
+      - task: Linux_ARMv6
+      - task: Linux_ARMv7
+      - task: Linux_ARM64
+      - task: macOS_64bit
+
+  Windows_32bit:
+    desc: Builds Windows 32 bit binaries
+    dir: "{{ .DIST_DIR }}"
+    cmds:
+      - |
+        docker run -v `pwd`/..:/home/build -w /home/build \
+        -e CGO_ENABLED=1 \
+        {{ .CONTAINER }}:{{ .CONTAINER_TAG }} \
+        --build-cmd "{{ .BUILD_COMMAND }}" \
+        -p "{{ .BUILD_PLATFORM }}"
+
+        zip {{ .PACKAGE_NAME}} {{ .PLATFORM_DIR }}/{{ .PROJECT_NAME }}.exe ../LICENSE.txt -j
+        sha256sum {{ .PACKAGE_NAME }} >> {{ .CHECKSUM_FILE }}
+
+    vars:
+      PLATFORM_DIR: "{{ .PROJECT_NAME }}_windows_386"
+      BUILD_COMMAND: "go build -o {{ .DIST_DIR }}/{{ .PLATFORM_DIR }}/{{ .PROJECT_NAME }}.exe {{ .LDFLAGS }}"
+      BUILD_PLATFORM: "windows/386"
+      CONTAINER_TAG: "{{ .GO_VERSION }}-main"
+      PACKAGE_PLATFORM: "Windows_32bit"
+      PACKAGE_NAME: "{{ .PROJECT_NAME }}_{{ .VERSION }}_{{ .PACKAGE_PLATFORM }}.zip"
+
+  Windows_64bit:
+    desc: Builds Windows 64 bit binaries
+    dir: "{{ .DIST_DIR }}"
+    cmds:
+      - |
+        docker run -v `pwd`/..:/home/build -w /home/build \
+        -e CGO_ENABLED=1 \
+        {{ .CONTAINER }}:{{ .CONTAINER_TAG }} \
+        --build-cmd "{{ .BUILD_COMMAND }}" \
+        -p "{{ .BUILD_PLATFORM }}"
+
+        zip {{ .PACKAGE_NAME}} {{ .PLATFORM_DIR }}/{{ .PROJECT_NAME }}.exe ../LICENSE.txt -j
+        sha256sum {{ .PACKAGE_NAME }} >> {{ .CHECKSUM_FILE }}
+
+    vars:
+      PLATFORM_DIR: "{{ .PROJECT_NAME }}_windows_amd64"
+      BUILD_COMMAND: "go build -o {{ .DIST_DIR }}/{{ .PLATFORM_DIR }}/{{ .PROJECT_NAME }}.exe {{ .LDFLAGS }}"
+      BUILD_PLATFORM: "windows/amd64"
+      CONTAINER_TAG: "{{ .GO_VERSION }}-main"
+      PACKAGE_PLATFORM: "Windows_64bit"
+      PACKAGE_NAME: "{{ .PROJECT_NAME }}_{{ .VERSION }}_{{ .PACKAGE_PLATFORM }}.zip"
+
+  Linux_32bit:
+    desc: Builds Linux 32 bit binaries
+    dir: "{{ .DIST_DIR }}"
+    cmds:
+      - |
+        docker run -v `pwd`/..:/home/build -w /home/build \
+        -e CGO_ENABLED=1 \
+        {{ .CONTAINER }}:{{ .CONTAINER_TAG }} \
+        --build-cmd "{{ .BUILD_COMMAND }}" \
+        -p "{{ .BUILD_PLATFORM }}"
+
+        tar cz -C {{ .PLATFORM_DIR }} {{ .PROJECT_NAME }} -C ../.. LICENSE.txt  -f {{ .PACKAGE_NAME }}
+        sha256sum {{ .PACKAGE_NAME }} >> {{ .CHECKSUM_FILE }}
+
+    vars:
+      PLATFORM_DIR: "{{ .PROJECT_NAME }}_linux_386"
+      BUILD_COMMAND: "go build -o {{ .DIST_DIR }}/{{ .PLATFORM_DIR }}/{{ .PROJECT_NAME }} {{ .LDFLAGS }}"
+      BUILD_PLATFORM: "linux/386"
+      CONTAINER_TAG: "{{ .GO_VERSION }}-main"
+      PACKAGE_PLATFORM: "Linux_32bit"
+      PACKAGE_NAME: "{{ .PROJECT_NAME }}_{{ .VERSION }}_{{ .PACKAGE_PLATFORM }}.tar.gz"
+
+  Linux_64bit:
+    desc: Builds Linux 64 bit binaries
+    dir: "{{ .DIST_DIR }}"
+    cmds:
+      - |
+        docker run -v `pwd`/..:/home/build -w /home/build \
+        -e CGO_ENABLED=1 \
+        {{ .CONTAINER }}:{{ .CONTAINER_TAG }} \
+        --build-cmd "{{ .BUILD_COMMAND }}" \
+        -p "{{ .BUILD_PLATFORM }}"
+
+        tar cz -C {{ .PLATFORM_DIR }} {{ .PROJECT_NAME }} -C ../.. LICENSE.txt  -f {{ .PACKAGE_NAME }}
+        sha256sum {{ .PACKAGE_NAME }} >> {{ .CHECKSUM_FILE }}
+
+    vars:
+      PLATFORM_DIR: "{{ .PROJECT_NAME }}_linux_amd64"
+      BUILD_COMMAND: "go build -o {{ .DIST_DIR }}/{{ .PLATFORM_DIR }}/{{ .PROJECT_NAME }} {{ .LDFLAGS }}"
+      BUILD_PLATFORM: "linux/amd64"
+      CONTAINER_TAG: "{{ .GO_VERSION }}-main"
+      PACKAGE_PLATFORM: "Linux_64bit"
+      PACKAGE_NAME: "{{ .PROJECT_NAME }}_{{ .VERSION }}_{{ .PACKAGE_PLATFORM }}.tar.gz"
+
+  Linux_ARMv7:
+    desc: Builds Linux ARMv7 binaries
+    dir: "{{ .DIST_DIR }}"
+    cmds:
+      - |
+        docker run -v `pwd`/..:/home/build -w /home/build \
+        -e CGO_ENABLED=1 \
+        {{ .CONTAINER }}:{{ .CONTAINER_TAG }} \
+        --build-cmd "{{ .BUILD_COMMAND }}" \
+        -p "{{ .BUILD_PLATFORM }}"
+
+        tar cz -C {{ .PLATFORM_DIR }} {{ .PROJECT_NAME }} -C ../.. LICENSE.txt  -f {{ .PACKAGE_NAME }}
+        sha256sum {{ .PACKAGE_NAME }} >> {{ .CHECKSUM_FILE }}
+
+    vars:
+      PLATFORM_DIR: "{{ .PROJECT_NAME }}_linux_arm_7"
+      BUILD_COMMAND: "go build -o {{ .DIST_DIR }}/{{ .PLATFORM_DIR }}/{{ .PROJECT_NAME }} {{ .LDFLAGS }}"
+      BUILD_PLATFORM: "linux/armv7"
+      CONTAINER_TAG: "{{ .GO_VERSION }}-arm"
+      PACKAGE_PLATFORM: "Linux_ARMv7"
+      PACKAGE_NAME: "{{ .PROJECT_NAME }}_{{ .VERSION }}_{{ .PACKAGE_PLATFORM }}.tar.gz"
+
+  Linux_ARMv6:
+    desc: Builds Linux ARMv6 binaries
+    dir: "{{ .DIST_DIR }}"
+    cmds:
+      - |
+        docker run -v `pwd`/..:/home/build -w /home/build \
+        -e CGO_ENABLED=1 \
+        {{ .CONTAINER }}:{{ .CONTAINER_TAG }} \
+        --build-cmd "{{ .BUILD_COMMAND }}" \
+        -p "{{ .BUILD_PLATFORM }}"
+
+        tar cz -C {{ .PLATFORM_DIR }} {{ .PROJECT_NAME }} -C ../.. LICENSE.txt  -f {{ .PACKAGE_NAME }}
+        sha256sum {{ .PACKAGE_NAME }} >> {{ .CHECKSUM_FILE }}
+
+    vars:
+      PLATFORM_DIR: "{{ .PROJECT_NAME }}_linux_arm_6"
+      BUILD_COMMAND: "go build -o {{ .DIST_DIR }}/{{ .PLATFORM_DIR }}/{{ .PROJECT_NAME }} {{ .LDFLAGS }}"
+      BUILD_PLATFORM: "linux/armv6"
+      CONTAINER_TAG: "{{ .GO_VERSION }}-arm"
+      PACKAGE_PLATFORM: "Linux_ARMv6"
+      PACKAGE_NAME: "{{ .PROJECT_NAME }}_{{ .VERSION }}_{{ .PACKAGE_PLATFORM }}.tar.gz"
+
+  Linux_ARM64:
+    desc: Builds Linux ARM64 binaries
+    dir: "{{ .DIST_DIR }}"
+    cmds:
+      - |
+        docker run -v `pwd`/..:/home/build -w /home/build \
+        -e CGO_ENABLED=1 \
+        {{ .CONTAINER }}:{{ .CONTAINER_TAG }} \
+        --build-cmd "{{ .BUILD_COMMAND }}" \
+        -p "{{ .BUILD_PLATFORM }}"
+
+        tar cz -C {{ .PLATFORM_DIR }} {{ .PROJECT_NAME }} -C ../.. LICENSE.txt  -f {{ .PACKAGE_NAME }}
+        sha256sum {{ .PACKAGE_NAME }} >> {{ .CHECKSUM_FILE }}
+
+    vars:
+      PLATFORM_DIR: "{{ .PROJECT_NAME }}_linux_arm_6"
+      BUILD_COMMAND: "go build -o {{ .DIST_DIR }}/{{ .PLATFORM_DIR }}/{{ .PROJECT_NAME }} {{ .LDFLAGS }}"
+      BUILD_PLATFORM: "linux/arm64"
+      CONTAINER_TAG: "{{ .GO_VERSION }}-arm"
+      PACKAGE_PLATFORM: "Linux_ARM64"
+      PACKAGE_NAME: "{{ .PROJECT_NAME }}_{{ .VERSION }}_{{ .PACKAGE_PLATFORM }}.tar.gz"
+
+  macOS_64bit:
+    desc: Builds Mac OS X 64 bit binaries
+    dir: "{{ .DIST_DIR }}"
+    cmds:
+      - |
+        docker run -v `pwd`/..:/home/build -w /home/build \
+        -e CGO_ENABLED=1 \
+        {{ .CONTAINER }}:{{ .CONTAINER_TAG }} \
+        --build-cmd "{{ .BUILD_COMMAND }}" \
+        -p "{{ .BUILD_PLATFORM }}"
+
+        tar cz -C {{ .PLATFORM_DIR }} {{ .PROJECT_NAME }} -C ../.. LICENSE.txt  -f {{ .PACKAGE_NAME }}
+        sha256sum {{ .PACKAGE_NAME }} >> {{ .CHECKSUM_FILE }}
+
+    vars:
+      PLATFORM_DIR: "{{ .PROJECT_NAME }}_osx_darwin_amd64"
+      BUILD_COMMAND: "go build -o {{ .DIST_DIR }}/{{ .PLATFORM_DIR }}/{{ .PROJECT_NAME }} {{ .LDFLAGS }}"
+      BUILD_PLATFORM: "darwin/amd64"
+      CONTAINER_TAG: "{{ .GO_VERSION }}-darwin"
+      PACKAGE_PLATFORM: "macOS_64bit"
+      PACKAGE_NAME: "{{ .PROJECT_NAME }}_{{ .VERSION }}_{{ .PACKAGE_PLATFORM }}.tar.gz"
+
+vars:
+  CONTAINER: "docker.elastic.co/beats-dev/golang-crossbuild"
+  GO_VERSION: "1.15.8"
+  CHECKSUM_FILE: "{{ .VERSION }}-checksums.txt"
diff --git a/Taskfile.yml b/Taskfile.yml
new file mode 100755
index 0000000..01f3d99
--- /dev/null
+++ b/Taskfile.yml
@@ -0,0 +1,24 @@
+version: "3"
+
+includes:
+  dist: ./DistTasks.yml
+
+tasks:
+  build:
+    desc: Build the project
+    cmds:
+      - go build -v {{.LDFLAGS}}
+
+vars:
+  PROJECT_NAME: "serial-discovery"
+  DIST_DIR: "dist"
+  VERSION:
+    sh: echo "$(git describe --tags --dirty --broken)"
+  TIMESTAMP:
+    sh: echo "$(date -u +"%Y-%m-%dT%H:%M:%SZ")"
+  LDFLAGS: >
+    -ldflags
+    '
+    -X github.com/arduino/serial-discovery/version.Tag={{.VERSION}}
+    -X github.com/arduino/serial-discovery/version.Timestamp={{.TIMESTAMP}}
+    '
diff --git a/args.go b/args.go
new file mode 100644
index 0000000..bac2f68
--- /dev/null
+++ b/args.go
@@ -0,0 +1,41 @@
+//
+// This file is part of serial-discovery.
+//
+// Copyright 2021 ARDUINO SA (http://www.arduino.cc/)
+//
+// This software is released under the GNU General Public License version 3,
+// which covers the main part of arduino-cli.
+// The terms of this license can be found at:
+// https://www.gnu.org/licenses/gpl-3.0.en.html
+//
+// You can be released from the requirements of the above licenses by purchasing
+// a commercial license. Buying such a license is mandatory if you want to modify or
+// otherwise use the software for commercial activities involving the Arduino
+// software without disclosing the source code of your own applications. To purchase
+// a commercial license, send an email to license@arduino.cc.
+//
+
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+var args struct {
+	showVersion bool
+}
+
+func parseArgs() {
+	for _, arg := range os.Args[1:] {
+		if arg == "" {
+			continue
+		}
+		if arg == "-v" || arg == "--version" {
+			args.showVersion = true
+			continue
+		}
+		fmt.Fprintf(os.Stderr, "invalid argument: %s\n", arg)
+		os.Exit(1)
+	}
+}
diff --git a/main.go b/main.go
index 3ddee54..69041a3 100644
--- a/main.go
+++ b/main.go
@@ -1,7 +1,7 @@
 //
 // This file is part of serial-discovery.
 //
-// Copyright 2018 ARDUINO SA (http://www.arduino.cc/)
+// Copyright 2021 ARDUINO SA (http://www.arduino.cc/)
 //
 // This software is released under the GNU General Public License version 3,
 // which covers the main part of arduino-cli.
@@ -26,10 +26,17 @@ import (
 	"sync"
 
 	"github.com/arduino/go-properties-orderedmap"
+	"github.com/arduino/serial-discovery/version"
 	"go.bug.st/serial/enumerator"
 )
 
 func main() {
+	parseArgs()
+	if args.showVersion {
+		fmt.Printf("serial-discovery %s (build timestamp: %s)\n", version.Tag, version.Timestamp)
+		return
+	}
+
 	syncStarted := false
 	var syncCloseChan chan<- bool
 
diff --git a/sync_windows.go b/sync_windows.go
index 37a278b..2a60a73 100644
--- a/sync_windows.go
+++ b/sync_windows.go
@@ -27,7 +27,7 @@ import (
 	"go.bug.st/serial/enumerator"
 )
 
-//go:generate go run $GOROOT/src/syscall/mksyscall_windows.go -output zsyscall_windows.go sync_windows.go
+//go:generate go run golang.org/x/sys/windows/mkwinsyscall -output zsyscall_windows.go sync_windows.go
 
 //sys getModuleHandle(moduleName *byte) (handle syscall.Handle, err error) = GetModuleHandleA
 //sys registerClass(wndClass *wndClass) (atom uint16, err error) = user32.RegisterClassA
diff --git a/version/version.go b/version/version.go
new file mode 100644
index 0000000..b7c9f31
--- /dev/null
+++ b/version/version.go
@@ -0,0 +1,24 @@
+//
+// This file is part of serial-discovery.
+//
+// Copyright 2021 ARDUINO SA (http://www.arduino.cc/)
+//
+// This software is released under the GNU General Public License version 3,
+// which covers the main part of arduino-cli.
+// The terms of this license can be found at:
+// https://www.gnu.org/licenses/gpl-3.0.en.html
+//
+// You can be released from the requirements of the above licenses by purchasing
+// a commercial license. Buying such a license is mandatory if you want to modify or
+// otherwise use the software for commercial activities involving the Arduino
+// software without disclosing the source code of your own applications. To purchase
+// a commercial license, send an email to license@arduino.cc.
+//
+
+package version
+
+// Tag is the current git tag
+var Tag = "snapshot"
+
+// Timestamp is the current timestamp
+var Timestamp = "unknown"
diff --git a/zsyscall_windows.go b/zsyscall_windows.go
index 5c671e1..4256568 100644
--- a/zsyscall_windows.go
+++ b/zsyscall_windows.go
@@ -19,6 +19,7 @@ const (
 
 var (
 	errERROR_IO_PENDING error = syscall.Errno(errnoERROR_IO_PENDING)
+	errERROR_EINVAL     error = syscall.EINVAL
 )
 
 // errnoErr returns common boxed Errno values, to prevent
@@ -26,7 +27,7 @@ var (
 func errnoErr(e syscall.Errno) error {
 	switch e {
 	case 0:
-		return nil
+		return errERROR_EINVAL
 	case errnoERROR_IO_PENDING:
 		return errERROR_IO_PENDING
 	}
@@ -41,37 +42,29 @@ var (
 	moduser32   = windows.NewLazySystemDLL("user32.dll")
 
 	procGetModuleHandleA            = modkernel32.NewProc("GetModuleHandleA")
-	procRegisterClassA              = moduser32.NewProc("RegisterClassA")
-	procDefWindowProcW              = moduser32.NewProc("DefWindowProcW")
 	procCreateWindowExA             = moduser32.NewProc("CreateWindowExA")
-	procRegisterDeviceNotificationA = moduser32.NewProc("RegisterDeviceNotificationA")
+	procDefWindowProcW              = moduser32.NewProc("DefWindowProcW")
+	procDispatchMessageA            = moduser32.NewProc("DispatchMessageA")
 	procGetMessageA                 = moduser32.NewProc("GetMessageA")
+	procRegisterClassA              = moduser32.NewProc("RegisterClassA")
+	procRegisterDeviceNotificationA = moduser32.NewProc("RegisterDeviceNotificationA")
 	procTranslateMessage            = moduser32.NewProc("TranslateMessage")
-	procDispatchMessageA            = moduser32.NewProc("DispatchMessageA")
 )
 
 func getModuleHandle(moduleName *byte) (handle syscall.Handle, err error) {
 	r0, _, e1 := syscall.Syscall(procGetModuleHandleA.Addr(), 1, uintptr(unsafe.Pointer(moduleName)), 0, 0)
 	handle = syscall.Handle(r0)
 	if handle == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+		err = errnoErr(e1)
 	}
 	return
 }
 
-func registerClass(wndClass *wndClass) (atom uint16, err error) {
-	r0, _, e1 := syscall.Syscall(procRegisterClassA.Addr(), 1, uintptr(unsafe.Pointer(wndClass)), 0, 0)
-	atom = uint16(r0)
-	if atom == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+func createWindowEx(exstyle uint32, className *byte, windowText *byte, style uint32, x int32, y int32, width int32, height int32, parent syscall.Handle, menu syscall.Handle, hInstance syscall.Handle, lpParam uintptr) (hwnd syscall.Handle, err error) {
+	r0, _, e1 := syscall.Syscall12(procCreateWindowExA.Addr(), 12, uintptr(exstyle), uintptr(unsafe.Pointer(className)), uintptr(unsafe.Pointer(windowText)), uintptr(style), uintptr(x), uintptr(y), uintptr(width), uintptr(height), uintptr(parent), uintptr(menu), uintptr(hInstance), uintptr(lpParam))
+	hwnd = syscall.Handle(r0)
+	if hwnd == 0 {
+		err = errnoErr(e1)
 	}
 	return
 }
@@ -82,28 +75,11 @@ func defWindowProc(hwnd syscall.Handle, msg uint32, wParam uintptr, lParam uintp
 	return
 }
 
-func createWindowEx(exstyle uint32, className *byte, windowText *byte, style uint32, x int32, y int32, width int32, height int32, parent syscall.Handle, menu syscall.Handle, hInstance syscall.Handle, lpParam uintptr) (hwnd syscall.Handle, err error) {
-	r0, _, e1 := syscall.Syscall12(procCreateWindowExA.Addr(), 12, uintptr(exstyle), uintptr(unsafe.Pointer(className)), uintptr(unsafe.Pointer(windowText)), uintptr(style), uintptr(x), uintptr(y), uintptr(width), uintptr(height), uintptr(parent), uintptr(menu), uintptr(hInstance), uintptr(lpParam))
-	hwnd = syscall.Handle(r0)
-	if hwnd == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
-	}
-	return
-}
-
-func registerDeviceNotification(recipient syscall.Handle, filter *devBroadcastDeviceInterface, flags uint32) (devHandle syscall.Handle, err error) {
-	r0, _, e1 := syscall.Syscall(procRegisterDeviceNotificationA.Addr(), 3, uintptr(recipient), uintptr(unsafe.Pointer(filter)), uintptr(flags))
-	devHandle = syscall.Handle(r0)
-	if devHandle == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+func dispatchMessage(msg *msg) (res int32, err error) {
+	r0, _, e1 := syscall.Syscall(procDispatchMessageA.Addr(), 1, uintptr(unsafe.Pointer(msg)), 0, 0)
+	res = int32(r0)
+	if res == 0 {
+		err = errnoErr(e1)
 	}
 	return
 }
@@ -112,30 +88,31 @@ func getMessage(msg *msg, hwnd syscall.Handle, msgFilterMin uint32, msgFilterMax
 	r0, _, e1 := syscall.Syscall6(procGetMessageA.Addr(), 4, uintptr(unsafe.Pointer(msg)), uintptr(hwnd), uintptr(msgFilterMin), uintptr(msgFilterMax), 0, 0)
 	res = int32(r0)
 	if res == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+		err = errnoErr(e1)
 	}
 	return
 }
 
-func translateMessage(msg *msg) (res bool) {
-	r0, _, _ := syscall.Syscall(procTranslateMessage.Addr(), 1, uintptr(unsafe.Pointer(msg)), 0, 0)
-	res = r0 != 0
+func registerClass(wndClass *wndClass) (atom uint16, err error) {
+	r0, _, e1 := syscall.Syscall(procRegisterClassA.Addr(), 1, uintptr(unsafe.Pointer(wndClass)), 0, 0)
+	atom = uint16(r0)
+	if atom == 0 {
+		err = errnoErr(e1)
+	}
 	return
 }
 
-func dispatchMessage(msg *msg) (res int32, err error) {
-	r0, _, e1 := syscall.Syscall(procDispatchMessageA.Addr(), 1, uintptr(unsafe.Pointer(msg)), 0, 0)
-	res = int32(r0)
-	if res == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+func registerDeviceNotification(recipient syscall.Handle, filter *devBroadcastDeviceInterface, flags uint32) (devHandle syscall.Handle, err error) {
+	r0, _, e1 := syscall.Syscall(procRegisterDeviceNotificationA.Addr(), 3, uintptr(recipient), uintptr(unsafe.Pointer(filter)), uintptr(flags))
+	devHandle = syscall.Handle(r0)
+	if devHandle == 0 {
+		err = errnoErr(e1)
 	}
 	return
 }
+
+func translateMessage(msg *msg) (res bool) {
+	r0, _, _ := syscall.Syscall(procTranslateMessage.Addr(), 1, uintptr(unsafe.Pointer(msg)), 0, 0)
+	res = r0 != 0
+	return
+}