feat: llgo monitor -target target -port port

cmd/internal/flags/flags.go

@@ -21,6 +21,7 @@ var Tags string
 var Target string
 var Emulator bool
 var Port string
+var BaudRate int
 var AbiMode int
 var CheckLinkArgs bool
 var CheckLLFiles bool
@@ -30,7 +31,6 @@ func AddBuildFlags(fs *flag.FlagSet) {
 	fs.BoolVar(&Verbose, "v", false, "Verbose mode")
 	fs.StringVar(&Tags, "tags", "", "Build tags")
 	fs.StringVar(&BuildEnv, "buildenv", "", "Build environment")
-	fs.StringVar(&Target, "target", "", "Target platform (e.g., rp2040, wasi)")
 	if buildenv.Dev {
 		fs.IntVar(&AbiMode, "abi", 2, "ABI mode (default 2). 0 = none, 1 = cfunc, 2 = allfunc.")
 		fs.BoolVar(&CheckLinkArgs, "check-linkargs", false, "check link args valid")
@@ -46,7 +46,9 @@ func AddEmulatorFlags(fs *flag.FlagSet) {
 }
 
 func AddEmbeddedFlags(fs *flag.FlagSet) {
+	fs.StringVar(&Target, "target", "", "Target platform (e.g., rp2040, wasi)")
 	fs.StringVar(&Port, "port", "", "Target port for flashing")
+	fs.IntVar(&BaudRate, "baudrate", 115200, "Baudrate for serial communication")
 }
 
 func AddCmpTestFlags(fs *flag.FlagSet) {
@@ -57,18 +59,18 @@ func UpdateConfig(conf *build.Config) {
 	conf.Tags = Tags
 	conf.Verbose = Verbose
 	conf.Target = Target
+	conf.Port = Port
+	conf.BaudRate = BaudRate
 	switch conf.Mode {
 	case build.ModeBuild:
 		conf.OutFile = OutputFile
 		conf.FileFormat = FileFormat
 	case build.ModeRun, build.ModeTest:
 		conf.Emulator = Emulator
-		conf.Port = Port
 	case build.ModeInstall:
-		conf.Port = Port
+
 	case build.ModeCmpTest:
 		conf.Emulator = Emulator
-		conf.Port = Port
 		conf.GenExpect = Gen
 	}
 	if buildenv.Dev {

cmd/internal/monitor/monitor.go

@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2025 The GoPlus Authors (goplus.org). All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package monitor
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/goplus/llgo/cmd/internal/base"
+	"github.com/goplus/llgo/cmd/internal/flags"
+	"github.com/goplus/llgo/internal/monitor"
+)
+
+// Cmd represents the monitor command.
+var Cmd = &base.Command{
+	UsageLine: "llgo monitor [flags] [executable]",
+	Short:     "Monitor serial output from device",
+}
+
+func init() {
+	flags.AddEmbeddedFlags(&Cmd.Flag)
+	Cmd.Run = runMonitor
+}
+
+func runMonitor(cmd *base.Command, args []string) {
+	cmd.Flag.Parse(args)
+	args = cmd.Flag.Args()
+
+	if len(args) > 1 {
+		fmt.Fprintf(os.Stderr, "llgo monitor: too many arguments\n")
+		os.Exit(1)
+	}
+
+	if flags.Port == "" && flags.Target == "" {
+		fmt.Fprintf(os.Stderr, "llgo monitor: must specify either -port or -target\n")
+		return
+	}
+
+	var executable string
+	if len(args) == 1 {
+		executable = args[0]
+	}
+
+	config := monitor.MonitorConfig{
+		Port:       flags.Port,
+		Target:     flags.Target,
+		BaudRate:   flags.BaudRate,
+		Executable: executable,
+	}
+
+	if err := monitor.Monitor(config, true); err != nil {
+		fmt.Fprintf(os.Stderr, "llgo monitor: %v\n", err)
+		os.Exit(1)
+	}
+}