Build and run for embeded

cmd/internal/flags/flags.go

@@ -19,6 +19,7 @@ var Verbose bool
 var BuildEnv string
 var Tags string
 var Target string
+var Emulator bool
 var AbiMode int
 var CheckLinkArgs bool
 var CheckLLFiles bool
@@ -39,6 +40,10 @@ func AddBuildFlags(fs *flag.FlagSet) {
 
 var Gen bool
 
+func AddRunFlags(fs *flag.FlagSet) {
+	fs.BoolVar(&Emulator, "emulator", false, "Run in emulator mode")
+}
+
 func AddCmpTestFlags(fs *flag.FlagSet) {
 	fs.BoolVar(&Gen, "gen", false, "Generate llgo.expect file")
 }
@@ -51,6 +56,8 @@ func UpdateConfig(conf *build.Config) {
 	case build.ModeBuild:
 		conf.OutFile = OutputFile
 		conf.FileFormat = FileFormat
+	case build.ModeRun:
+		conf.Emulator = Emulator
 	case build.ModeCmpTest:
 		conf.GenExpect = Gen
 	}

cmd/internal/run/run.go

@@ -50,6 +50,7 @@ func init() {
 	base.PassBuildFlags(Cmd)
 	flags.AddBuildFlags(&Cmd.Flag)
 	flags.AddBuildFlags(&CmpTestCmd.Flag)
+	flags.AddRunFlags(&Cmd.Flag)
 	flags.AddCmpTestFlags(&CmpTestCmd.Flag)
 }
 

doc/Embedded_Cmd.md

@@ -0,0 +1,52 @@
+# LLGo Embedded Development Command Line Options
+
+## Flags
+
+- `-o <file>` - Specify output file name
+- `-target <platform>` - Specify target platform for cross-compilation
+- `-file-format <format>` - Convert to specified format (**requires `-target`**)
+  - Supported: `elf` (default), `bin`, `hex`, `uf2`, `zip`, `img`
+- `-emulator` - Run using emulator (auto-detects required format)
+- `-d <device>` - Target device for flashing or testing
+
+## Commands
+
+### llgo build
+Compile program to output file.
+- No `-target`: Native executable
+- With `-target`: ELF executable (or `-file-format` if specified)
+
+### llgo run  
+Compile and run program.
+- No `-target`: Run locally
+- With `-target`: Run on device or emulator
+
+### llgo test
+Compile and run tests.
+- No `-target`: Run tests locally
+- With `-target`: Run tests on device or emulator
+- Supports `-emulator` and `-d` flags
+
+### llgo install
+Install program or flash to device.
+- No `-target`: Install to `$GOPATH/bin`
+- With `-target`: Flash to device (use `-d` to specify device)
+
+## Examples
+
+```bash
+# Native development
+llgo build hello.go                              # -> hello
+llgo build -o myapp hello.go                     # -> myapp
+llgo run hello.go                                # run locally
+llgo install hello.go                            # install to bin
+
+# Cross-compilation
+llgo build -target esp32 hello.go                # -> hello (ELF)
+llgo build -target esp32 -file-format bin hello.go  # -> hello.bin
+llgo run -target esp32 hello.go                  # run on ESP32
+llgo run -target esp32 -emulator hello.go        # run in emulator
+llgo test -target esp32 -d /dev/ttyUSB0          # run tests on device
+llgo test -target esp32 -emulator                # run tests in emulator
+llgo install -target esp32 -d /dev/ttyUSB0 hello.go  # flash to specific device
+```

internal/build/build.go

@@ -79,6 +79,7 @@ type Config struct {
 	AppExt        string   // ".exe" on Windows, empty on Unix
 	OutFile       string   // only valid for ModeBuild when len(pkgs) == 1
 	FileFormat    string   // File format override (e.g., "bin", "hex", "elf", "uf2", "zip") - takes precedence over target's default
+	Emulator      bool     // only valid for ModeRun - run in emulator mode
 	RunArgs       []string // only valid for ModeRun
 	Mode          Mode
 	AbiMode       AbiMode
@@ -628,83 +629,18 @@ func compileExtraFiles(ctx *context, verbose bool) ([]string, error) {
 	return objFiles, nil
 }
 
-// generateOutputFilenames generates the final output filename (app) and intermediate filename (orgApp)
-// based on configuration and build context.
-func generateOutputFilenames(outFile, binPath, appExt, binExt, pkgName string, mode Mode, isMultiplePkgs bool) (app, orgApp string, err error) {
-	if outFile == "" {
-		if mode == ModeBuild && isMultiplePkgs {
-			// For multiple packages in ModeBuild mode, use temporary file
-			name := pkgName
-			if binExt != "" {
-				name += "*" + binExt
-			} else {
-				name += "*" + appExt
-			}
-			tmpFile, err := os.CreateTemp("", name)
-			if err != nil {
-				return "", "", err
-			}
-			app = tmpFile.Name()
-			tmpFile.Close()
-		} else {
-			app = filepath.Join(binPath, pkgName+appExt)
-		}
-		orgApp = app
-	} else {
-		// outFile is not empty, use it as base part
-		base := outFile
-		if binExt != "" {
-			// If binExt has value, use temporary file as orgApp for firmware conversion
-			tmpFile, err := os.CreateTemp("", "llgo-*"+appExt)
-			if err != nil {
-				return "", "", err
-			}
-			orgApp = tmpFile.Name()
-			tmpFile.Close()
-			// Check if base already ends with binExt, if so, don't add it again
-			if strings.HasSuffix(base, binExt) {
-				app = base
-			} else {
-				app = base + binExt
-			}
-		} else {
-			// No binExt, use base + AppExt directly
-			if filepath.Ext(base) == "" {
-				app = base + appExt
-			} else {
-				app = base
-			}
-			orgApp = app
-		}
-	}
-	return app, orgApp, nil
-}
-
 func linkMainPkg(ctx *context, pkg *packages.Package, pkgs []*aPackage, global llssa.Package, conf *Config, mode Mode, verbose bool) {
 	pkgPath := pkg.PkgPath
 	name := path.Base(pkgPath)
 	binFmt := ctx.crossCompile.BinaryFormat
-	binExt := firmware.BinaryExt(binFmt)
 
-	// Determine final output extension from user-specified file format
+	// Generate output configuration using the centralized function
-	outExt := binExt
+	outputCfg, err := GenOutputs(conf, name, len(ctx.initial) > 1, ctx.crossCompile.Emulator, binFmt)
-	if conf.FileFormat != "" {
-		outExt = firmware.GetFileExtFromFormat(conf.FileFormat)
-	}
-
-	// app: converted firmware output file or executable file
-	// orgApp: before converted output file
-	app, orgApp, err := generateOutputFilenames(
-		conf.OutFile,
-		conf.BinPath,
-		conf.AppExt,
-		outExt,
-		name,
-		mode,
-		len(ctx.initial) > 1,
-	)
 	check(err)
 
+	app := outputCfg.OutPath
+	orgApp := outputCfg.IntPath
+
 	needRuntime := false
 	needPyInit := false
 	pkgsMap := make(map[*packages.Package]*aPackage, len(pkgs))
@@ -769,28 +705,27 @@ func linkMainPkg(ctx *context, pkg *packages.Package, pkgs []*aPackage, global l
 	// Handle firmware conversion and file format conversion
 	currentApp := orgApp
 
-	// Determine if firmware conversion is needed based on mode
+	useEmulator := false
-	needFirmwareConversion := false
+	if mode == ModeRun && conf.Emulator {
-	if mode == ModeBuild {
+		if ctx.crossCompile.Emulator == "" {
-		// For build command, do firmware conversion if file-format is specified
+			panic(fmt.Errorf("target %s does not have emulator configured", conf.Target))
-		needFirmwareConversion = conf.FileFormat != ""
+		}
-	} else {
+		useEmulator = true
-		// For run and install commands, do firmware conversion if binExt is set
-		needFirmwareConversion = binExt != ""
 	}
 
 	// Step 1: Firmware conversion if needed
-	if needFirmwareConversion {
+	if outputCfg.NeedFwGen {
-		if outExt == binExt {
+		if outputCfg.DirectGen {
-			// Direct conversion to final output
+			// Direct conversion to final output (including .img case)
 			if verbose {
-				fmt.Fprintf(os.Stderr, "Converting to firmware format: %s (%s -> %s)\n", ctx.crossCompile.BinaryFormat, currentApp, app)
+				fmt.Fprintf(os.Stderr, "Converting to firmware format: %s (%s -> %s)\n", outputCfg.BinFmt, currentApp, app)
 			}
-			err = firmware.MakeFirmwareImage(currentApp, app, ctx.crossCompile.BinaryFormat, ctx.crossCompile.FormatDetail)
+			err = firmware.MakeFirmwareImage(currentApp, app, outputCfg.BinFmt, ctx.crossCompile.FormatDetail)
 			check(err)
 			currentApp = app
 		} else {
 			// Convert to intermediate file first
+			binExt := firmware.BinaryExt(ctx.crossCompile.BinaryFormat)
 			tmpFile, err := os.CreateTemp("", "llgo-*"+binExt)
 			check(err)
 			tmpFile.Close()
@@ -813,12 +748,12 @@ func linkMainPkg(ctx *context, pkg *packages.Package, pkgs []*aPackage, global l
 
 	// Step 2: File format conversion if needed
 	if currentApp != app {
-		if conf.FileFormat != "" {
+		if outputCfg.FileFmt != "" {
 			// File format conversion
 			if verbose {
-				fmt.Fprintf(os.Stderr, "Converting to file format: %s (%s -> %s)\n", conf.FileFormat, currentApp, app)
+				fmt.Fprintf(os.Stderr, "Converting to file format: %s (%s -> %s)\n", outputCfg.FileFmt, currentApp, app)
 			}
-			err = firmware.ConvertOutput(currentApp, app, binFmt, conf.FileFormat)
+			err = firmware.ConvertOutput(currentApp, app, binFmt, outputCfg.FileFmt)
 			check(err)
 		} else {
 			// Just move/copy the file
@@ -845,6 +780,12 @@ func linkMainPkg(ctx *context, pkg *packages.Package, pkgs []*aPackage, global l
 			}
 		}
 	case ModeRun:
+		if useEmulator {
+			if verbose {
+				fmt.Fprintf(os.Stderr, "Using emulator: %s\n", ctx.crossCompile.Emulator)
+			}
+			runInEmulator(app, ctx.crossCompile.Emulator, conf.RunArgs, verbose)
+		} else {
 			args := make([]string, 0, len(conf.RunArgs)+1)
 			copy(args, conf.RunArgs)
 			if isWasmTarget(conf.Goos) {
@@ -879,6 +820,7 @@ func linkMainPkg(ctx *context, pkg *packages.Package, pkgs []*aPackage, global l
 			if s := cmd.ProcessState; s != nil {
 				mockable.Exit(s.ExitCode())
 			}
+		}
 	case ModeCmpTest:
 		cmpTest(filepath.Dir(pkg.GoFiles[0]), pkgPath, app, conf.GenExpect, conf.RunArgs)
 	}
@@ -1371,6 +1313,57 @@ func findDylibDep(exe, lib string) string {
 
 type none struct{}
 
+// runInEmulator runs the application in emulator by formatting the emulator command template
+func runInEmulator(appPath, emulatorTemplate string, runArgs []string, verbose bool) {
+	// Build environment map for template variable expansion
+	envs := map[string]string{
+		"":    appPath, // {} expands to app path
+		"bin": appPath,
+		"hex": appPath,
+		"zip": appPath,
+		"img": appPath,
+		"uf2": appPath,
+	}
+
+	// Expand the emulator command template
+	emulatorCmd := emulatorTemplate
+	for placeholder, path := range envs {
+		var target string
+		if placeholder == "" {
+			target = "{}"
+		} else {
+			target = "{" + placeholder + "}"
+		}
+		emulatorCmd = strings.ReplaceAll(emulatorCmd, target, path)
+	}
+
+	if verbose {
+		fmt.Fprintf(os.Stderr, "Running in emulator: %s\n", emulatorCmd)
+	}
+
+	// Parse command and arguments
+	cmdParts := strings.Fields(emulatorCmd)
+	if len(cmdParts) == 0 {
+		panic(fmt.Errorf("empty emulator command"))
+	}
+
+	// Add run arguments to the end
+	cmdParts = append(cmdParts, runArgs...)
+
+	// Execute the emulator command
+	cmd := exec.Command(cmdParts[0], cmdParts[1:]...)
+	cmd.Stdin = os.Stdin
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	err := cmd.Run()
+	if err != nil {
+		panic(err)
+	}
+	if s := cmd.ProcessState; s != nil {
+		mockable.Exit(s.ExitCode())
+	}
+}
+
 func check(err error) {
 	if err != nil {
 		panic(err)

internal/build/build_test.go

@@ -8,7 +8,6 @@ import (
 	"fmt"
 	"io"
 	"os"
-	"strings"
 	"testing"
 
 	"github.com/goplus/llgo/internal/mockable"
@@ -95,172 +94,4 @@ func TestCmpTest(t *testing.T) {
 	mockRun([]string{"../../cl/_testgo/runtest"}, &Config{Mode: ModeCmpTest})
 }
 
-func TestGenerateOutputFilenames(t *testing.T) {
+// TestGenerateOutputFilenames removed - functionality moved to filename_test.go
-	tests := []struct {
-		name           string
-		outFile        string
-		binPath        string
-		appExt         string
-		binExt         string
-		pkgName        string
-		mode           Mode
-		isMultiplePkgs bool
-		wantAppSuffix  string
-		wantOrgAppDiff bool // true if orgApp should be different from app
-		wantErr        bool
-	}{
-		{
-			name:           "empty outFile, single package",
-			outFile:        "",
-			binPath:        "/usr/local/bin",
-			appExt:         "",
-			binExt:         "",
-			pkgName:        "hello",
-			mode:           ModeBuild,
-			isMultiplePkgs: false,
-			wantAppSuffix:  "/usr/local/bin/hello",
-			wantOrgAppDiff: false,
-		},
-		{
-			name:           "empty outFile with appExt",
-			outFile:        "",
-			binPath:        "/usr/local/bin",
-			appExt:         ".exe",
-			binExt:         "",
-			pkgName:        "hello",
-			mode:           ModeBuild,
-			isMultiplePkgs: false,
-			wantAppSuffix:  "/usr/local/bin/hello.exe",
-			wantOrgAppDiff: false,
-		},
-		{
-			name:           "outFile without binExt",
-			outFile:        "myapp",
-			binPath:        "/usr/local/bin",
-			appExt:         ".exe",
-			binExt:         "",
-			pkgName:        "hello",
-			mode:           ModeBuild,
-			isMultiplePkgs: false,
-			wantAppSuffix:  "myapp.exe",
-			wantOrgAppDiff: false,
-		},
-		{
-			name:           "outFile with existing extension, no binExt",
-			outFile:        "myapp.exe",
-			binPath:        "/usr/local/bin",
-			appExt:         ".exe",
-			binExt:         "",
-			pkgName:        "hello",
-			mode:           ModeBuild,
-			isMultiplePkgs: false,
-			wantAppSuffix:  "myapp.exe",
-			wantOrgAppDiff: false,
-		},
-		{
-			name:           "outFile with binExt, different from existing extension",
-			outFile:        "myapp",
-			binPath:        "/usr/local/bin",
-			appExt:         ".exe",
-			binExt:         ".bin",
-			pkgName:        "hello",
-			mode:           ModeBuild,
-			isMultiplePkgs: false,
-			wantAppSuffix:  "myapp.bin",
-			wantOrgAppDiff: true,
-		},
-		{
-			name:           "outFile already ends with binExt",
-			outFile:        "t.bin",
-			binPath:        "/usr/local/bin",
-			appExt:         ".exe",
-			binExt:         ".bin",
-			pkgName:        "hello",
-			mode:           ModeBuild,
-			isMultiplePkgs: false,
-			wantAppSuffix:  "t.bin",
-			wantOrgAppDiff: true,
-		},
-		{
-			name:           "outFile with full path already ends with binExt",
-			outFile:        "/path/to/t.bin",
-			binPath:        "/usr/local/bin",
-			appExt:         ".exe",
-			binExt:         ".bin",
-			pkgName:        "hello",
-			mode:           ModeBuild,
-			isMultiplePkgs: false,
-			wantAppSuffix:  "/path/to/t.bin",
-			wantOrgAppDiff: true,
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			app, orgApp, err := generateOutputFilenames(
-				tt.outFile,
-				tt.binPath,
-				tt.appExt,
-				tt.binExt,
-				tt.pkgName,
-				tt.mode,
-				tt.isMultiplePkgs,
-			)
-
-			if (err != nil) != tt.wantErr {
-				t.Errorf("generateOutputFilenames() error = %v, wantErr %v", err, tt.wantErr)
-				return
-			}
-
-			if tt.wantAppSuffix != "" {
-				if app != tt.wantAppSuffix {
-					t.Errorf("generateOutputFilenames() app = %v, want %v", app, tt.wantAppSuffix)
-				}
-			}
-
-			if tt.wantOrgAppDiff {
-				if app == orgApp {
-					t.Errorf("generateOutputFilenames() orgApp should be different from app, but both are %v", app)
-				}
-				// Clean up temp file
-				if orgApp != "" && strings.Contains(orgApp, "llgo-") {
-					os.Remove(orgApp)
-				}
-			} else {
-				if app != orgApp {
-					t.Errorf("generateOutputFilenames() orgApp = %v, want %v (same as app)", orgApp, app)
-				}
-			}
-		})
-	}
-}
-
-func TestGenerateOutputFilenames_EdgeCases(t *testing.T) {
-	// Test case where outFile has same extension as binExt
-	app, orgApp, err := generateOutputFilenames(
-		"firmware.bin",
-		"/usr/local/bin",
-		".exe",
-		".bin",
-		"esp32app",
-		ModeBuild,
-		false,
-	)
-
-	if err != nil {
-		t.Fatalf("Unexpected error: %v", err)
-	}
-
-	if app != "firmware.bin" {
-		t.Errorf("Expected app to be 'firmware.bin', got '%s'", app)
-	}
-
-	if app == orgApp {
-		t.Errorf("Expected orgApp to be different from app when binExt is present, but both are '%s'", app)
-	}
-
-	// Clean up temp file
-	if orgApp != "" && strings.Contains(orgApp, "llgo-") {
-		os.Remove(orgApp)
-	}
-}

internal/build/outputs.go

@@ -0,0 +1,192 @@
+package build
+
+import (
+	"os"
+	"path/filepath"
+
+	"github.com/goplus/llgo/internal/firmware"
+)
+
+// OutputCfg contains the generated output paths and conversion configuration
+type OutputCfg struct {
+	OutPath   string // Final output file path
+	IntPath   string // Intermediate file path (for two-stage conversion)
+	OutExt    string // Output file extension
+	FileFmt   string // File format (from conf.FileFormat or extracted from emulator)
+	BinFmt    string // Binary format for firmware conversion (may have -img suffix)
+	NeedFwGen bool   // Whether firmware image generation is needed
+	DirectGen bool   // True if can generate firmware directly without intermediate file
+}
+
+// GenOutputs generates appropriate output paths based on the configuration
+func GenOutputs(conf *Config, pkgName string, multiPkg bool, emulator, binFmt string) (OutputCfg, error) {
+	var cfg OutputCfg
+
+	// Calculate binary extension and set up format info
+	binExt := firmware.BinaryExt(binFmt)
+	cfg.BinFmt = binFmt
+
+	// Determine output format and extension
+	cfg.FileFmt, cfg.OutExt = determineFormat(conf, emulator)
+
+	// Handle special .img case and set conversion flags
+	cfg.DirectGen = shouldDirectGen(cfg.OutExt, binExt)
+	if cfg.OutExt == ".img" {
+		cfg.BinFmt = binFmt + "-img"
+	}
+
+	// Determine if firmware generation is needed
+	cfg.NeedFwGen = needsFwGen(conf, cfg.OutExt, binExt)
+
+	// Generate paths based on mode
+	switch conf.Mode {
+	case ModeBuild:
+		return genBuildOutputs(conf, pkgName, multiPkg, cfg)
+	case ModeRun, ModeTest, ModeCmpTest:
+		return genRunOutputs(pkgName, cfg, conf.AppExt)
+	case ModeInstall:
+		return genInstallOutputs(conf, pkgName, cfg, binExt)
+	default:
+		return cfg, nil
+	}
+}
+
+// determineFormat determines the file format and extension
+func determineFormat(conf *Config, emulator string) (format, ext string) {
+	if conf.FileFormat != "" {
+		// User specified file format
+		return conf.FileFormat, firmware.GetFileExtFromFormat(conf.FileFormat)
+	}
+
+	if conf.Mode == ModeRun && conf.Emulator && emulator != "" {
+		// Emulator mode - extract format from emulator command
+		if emulatorFmt := firmware.ExtractFileFormatFromEmulator(emulator); emulatorFmt != "" {
+			return emulatorFmt, firmware.GetFileExtFromFormat(emulatorFmt)
+		}
+	}
+
+	return "", ""
+}
+
+// shouldDirectGen determines if direct firmware generation is possible
+func shouldDirectGen(outExt, binExt string) bool {
+	return outExt == "" || outExt == binExt || outExt == ".img"
+}
+
+// needsFwGen determines if firmware generation is needed
+func needsFwGen(conf *Config, outExt, binExt string) bool {
+	switch conf.Mode {
+	case ModeBuild:
+		return conf.FileFormat != ""
+	case ModeRun, ModeTest, ModeCmpTest:
+		if conf.Emulator {
+			return outExt != ""
+		}
+		return binExt != ""
+	case ModeInstall:
+		return binExt != ""
+	default:
+		return false
+	}
+}
+
+// genBuildOutputs generates output paths for build mode
+func genBuildOutputs(conf *Config, pkgName string, multiPkg bool, cfg OutputCfg) (OutputCfg, error) {
+	if conf.OutFile == "" && multiPkg {
+		// Multiple packages, use temp file
+		return genTempOutputs(pkgName, cfg, conf.AppExt)
+	}
+
+	// Single package build
+	baseName := pkgName
+	if conf.OutFile != "" {
+		baseName = conf.OutFile
+	}
+
+	if cfg.OutExt != "" {
+		// Need format conversion: ELF -> format
+		if err := setupTwoStageGen(&cfg, baseName, conf.AppExt); err != nil {
+			return cfg, err
+		}
+	} else {
+		// Direct output
+		cfg.OutPath = baseName + conf.AppExt
+		cfg.IntPath = cfg.OutPath
+	}
+
+	return cfg, nil
+}
+
+// genRunOutputs generates output paths for run mode
+func genRunOutputs(pkgName string, cfg OutputCfg, appExt string) (OutputCfg, error) {
+	// Always use temp files for run mode
+	return genTempOutputs(pkgName, cfg, appExt)
+}
+
+// genInstallOutputs generates output paths for install mode (flashing to device)
+func genInstallOutputs(conf *Config, pkgName string, cfg OutputCfg, binExt string) (OutputCfg, error) {
+	// Install mode with target means flashing to device, use temp files like run mode
+	if binExt != "" || cfg.OutExt != "" {
+		// Flash to device - use temp files for firmware generation
+		return genTempOutputs(pkgName, cfg, conf.AppExt)
+	} else {
+		// Install to BinPath (traditional install without target)
+		cfg.OutPath = filepath.Join(conf.BinPath, pkgName+conf.AppExt)
+		cfg.IntPath = cfg.OutPath
+	}
+
+	return cfg, nil
+}
+
+// setupTwoStageGen sets up paths for two-stage generation
+func setupTwoStageGen(cfg *OutputCfg, baseName, appExt string) error {
+	// Create temp file for intermediate ELF
+	tmpFile, err := os.CreateTemp("", "llgo-*"+appExt)
+	if err != nil {
+		return err
+	}
+	tmpFile.Close()
+	cfg.IntPath = tmpFile.Name()
+
+	// Set final output path
+	if baseName != "" {
+		if filepath.Ext(baseName) == cfg.OutExt {
+			cfg.OutPath = baseName
+		} else {
+			cfg.OutPath = baseName + cfg.OutExt
+		}
+	}
+
+	return nil
+}
+
+// genTempOutputs creates temporary output file paths
+func genTempOutputs(pkgName string, cfg OutputCfg, appExt string) (OutputCfg, error) {
+	if cfg.OutExt != "" {
+		// Need format conversion: create temp ELF, then convert to final format
+		tmpFile, err := os.CreateTemp("", "llgo-*"+appExt)
+		if err != nil {
+			return cfg, err
+		}
+		tmpFile.Close()
+		cfg.IntPath = tmpFile.Name()
+
+		finalTmp, err := os.CreateTemp("", pkgName+"-*"+cfg.OutExt)
+		if err != nil {
+			return cfg, err
+		}
+		finalTmp.Close()
+		cfg.OutPath = finalTmp.Name()
+	} else {
+		// Direct output
+		tmpFile, err := os.CreateTemp("", pkgName+"-*"+appExt)
+		if err != nil {
+			return cfg, err
+		}
+		tmpFile.Close()
+		cfg.OutPath = tmpFile.Name()
+		cfg.IntPath = cfg.OutPath
+	}
+
+	return cfg, nil
+}

internal/build/outputs_test.go

@@ -0,0 +1,448 @@
+//go:build !llgo
+// +build !llgo
+
+package build
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestGenOutputs(t *testing.T) {
+	tests := []struct {
+		name          string
+		conf          *Config
+		pkgName       string
+		multiPkg      bool
+		emulator      string
+		wantOutPath   string // use empty string to indicate temp file
+		wantIntPath   string // use empty string to indicate same as outPath
+		wantOutExt    string
+		wantFileFmt   string
+		wantBinFmt    string
+		wantDirectGen bool
+	}{
+		{
+			name: "build without target",
+			conf: &Config{
+				Mode:    ModeBuild,
+				BinPath: "/go/bin",
+				AppExt:  "",
+			},
+			pkgName:       "hello",
+			wantOutPath:   "hello",
+			wantOutExt:    "",
+			wantFileFmt:   "",
+			wantBinFmt:    "esp32",
+			wantDirectGen: true,
+		},
+		{
+			name: "build with -o",
+			conf: &Config{
+				Mode:    ModeBuild,
+				OutFile: "myapp",
+				AppExt:  "",
+			},
+			pkgName:       "hello",
+			wantOutPath:   "myapp",
+			wantOutExt:    "",
+			wantFileFmt:   "",
+			wantBinFmt:    "esp32",
+			wantDirectGen: true,
+		},
+		{
+			name: "build with target and file-format",
+			conf: &Config{
+				Mode:       ModeBuild,
+				BinPath:    "/go/bin",
+				AppExt:     "",
+				FileFormat: "bin",
+				Target:     "esp32",
+			},
+			pkgName:       "hello",
+			wantOutPath:   "hello.bin",
+			wantOutExt:    ".bin",
+			wantFileFmt:   "bin",
+			wantBinFmt:    "esp32",
+			wantDirectGen: true,
+		},
+		{
+			name: "build with target, -o and file-format",
+			conf: &Config{
+				Mode:       ModeBuild,
+				OutFile:    "myapp",
+				AppExt:     "",
+				FileFormat: "hex",
+				Target:     "esp32",
+			},
+			pkgName:       "hello",
+			wantOutPath:   "myapp.hex",
+			wantOutExt:    ".hex",
+			wantFileFmt:   "hex",
+			wantBinFmt:    "esp32",
+			wantDirectGen: false,
+		},
+		{
+			name: "build with target, -o has correct extension and file-format",
+			conf: &Config{
+				Mode:       ModeBuild,
+				OutFile:    "myapp.hex",
+				AppExt:     "",
+				FileFormat: "hex",
+				Target:     "esp32",
+			},
+			pkgName:       "hello",
+			wantOutPath:   "myapp.hex",
+			wantOutExt:    ".hex",
+			wantFileFmt:   "hex",
+			wantBinFmt:    "esp32",
+			wantDirectGen: false,
+		},
+		{
+			name: "run without target",
+			conf: &Config{
+				Mode:   ModeRun,
+				AppExt: "",
+			},
+			pkgName:       "hello",
+			wantOutPath:   "", // temp file
+			wantOutExt:    "",
+			wantFileFmt:   "",
+			wantBinFmt:    "esp32",
+			wantDirectGen: true,
+		},
+		{
+			name: "run with target",
+			conf: &Config{
+				Mode:   ModeRun,
+				AppExt: "",
+				Target: "esp32",
+			},
+			pkgName:       "hello",
+			wantOutPath:   "", // temp file
+			wantOutExt:    "",
+			wantFileFmt:   "",
+			wantBinFmt:    "esp32",
+			wantDirectGen: true,
+		},
+		{
+			name: "run with target and emulator",
+			conf: &Config{
+				Mode:     ModeRun,
+				AppExt:   "",
+				Target:   "esp32",
+				Emulator: true,
+			},
+			pkgName:       "hello",
+			emulator:      "qemu-system-xtensa -machine esp32 -drive file={hex},if=mtd,format=raw",
+			wantOutPath:   "", // temp file
+			wantOutExt:    ".hex",
+			wantFileFmt:   "hex",
+			wantBinFmt:    "esp32",
+			wantDirectGen: false,
+		},
+		{
+			name: "build with img file-format",
+			conf: &Config{
+				Mode:       ModeBuild,
+				BinPath:    "/go/bin",
+				AppExt:     "",
+				FileFormat: "img",
+				Target:     "esp32",
+			},
+			pkgName:       "hello",
+			wantOutPath:   "hello.img",
+			wantOutExt:    ".img",
+			wantFileFmt:   "img",
+			wantBinFmt:    "esp32-img",
+			wantDirectGen: true,
+		},
+		{
+			name: "test without target",
+			conf: &Config{
+				Mode:   ModeTest,
+				AppExt: "",
+			},
+			pkgName:       "hello",
+			wantOutPath:   "", // temp file
+			wantOutExt:    "",
+			wantFileFmt:   "",
+			wantBinFmt:    "esp32",
+			wantDirectGen: true,
+		},
+		{
+			name: "test with target",
+			conf: &Config{
+				Mode:   ModeTest,
+				AppExt: "",
+				Target: "esp32",
+			},
+			pkgName:       "hello",
+			wantOutPath:   "", // temp file
+			wantOutExt:    "",
+			wantFileFmt:   "",
+			wantBinFmt:    "esp32",
+			wantDirectGen: true,
+		},
+		{
+			name: "cmptest without target",
+			conf: &Config{
+				Mode:   ModeCmpTest,
+				AppExt: "",
+			},
+			pkgName:       "hello",
+			wantOutPath:   "", // temp file
+			wantOutExt:    "",
+			wantFileFmt:   "",
+			wantBinFmt:    "esp32",
+			wantDirectGen: true,
+		},
+		{
+			name: "install without target",
+			conf: &Config{
+				Mode:    ModeInstall,
+				BinPath: "/go/bin",
+				AppExt:  "",
+			},
+			pkgName:       "hello",
+			wantOutPath:   "/go/bin/hello",
+			wantOutExt:    "",
+			wantFileFmt:   "",
+			wantBinFmt:    "",
+			wantDirectGen: true,
+		},
+		{
+			name: "install with esp32 target (flash to device)",
+			conf: &Config{
+				Mode:    ModeInstall,
+				BinPath: "/go/bin",
+				AppExt:  "",
+				Target:  "esp32",
+			},
+			pkgName:       "hello",
+			wantOutPath:   "", // temp file for flashing
+			wantOutExt:    "",
+			wantFileFmt:   "",
+			wantBinFmt:    "esp32",
+			wantDirectGen: true,
+		},
+		{
+			name: "install with file format (flash to device)",
+			conf: &Config{
+				Mode:       ModeInstall,
+				BinPath:    "/go/bin",
+				AppExt:     "",
+				FileFormat: "hex",
+				Target:     "esp32",
+			},
+			pkgName:       "hello",
+			wantOutPath:   "", // temp file for flashing
+			wantOutExt:    ".hex",
+			wantFileFmt:   "hex",
+			wantBinFmt:    "esp32",
+			wantDirectGen: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Determine input binFmt - remove -img suffix if present as it will be added by the code
+			inputBinFmt := tt.wantBinFmt
+			if strings.HasSuffix(inputBinFmt, "-img") && tt.wantFileFmt == "img" {
+				inputBinFmt = strings.TrimSuffix(inputBinFmt, "-img")
+			}
+			result, err := GenOutputs(tt.conf, tt.pkgName, tt.multiPkg, tt.emulator, inputBinFmt)
+			if err != nil {
+				t.Fatalf("GenOutputs() error = %v", err)
+			}
+
+			if tt.wantOutExt != result.OutExt {
+				t.Errorf("GenOutputs() OutExt = %v, want %v", result.OutExt, tt.wantOutExt)
+			}
+
+			if tt.wantFileFmt != result.FileFmt {
+				t.Errorf("GenOutputs() FileFmt = %v, want %v", result.FileFmt, tt.wantFileFmt)
+			}
+
+			if tt.wantBinFmt != result.BinFmt {
+				t.Errorf("GenOutputs() BinFmt = %v, want %v", result.BinFmt, tt.wantBinFmt)
+			}
+
+			if tt.wantDirectGen != result.DirectGen {
+				t.Errorf("GenOutputs() DirectGen = %v, want %v", result.DirectGen, tt.wantDirectGen)
+			}
+
+			if tt.wantOutPath != "" {
+				// Check exact match for non-temp files
+				if result.OutPath != tt.wantOutPath {
+					t.Errorf("GenOutputs() OutPath = %v, want %v", result.OutPath, tt.wantOutPath)
+				}
+			} else {
+				// Check temp file pattern for temp files
+				if result.OutPath == "" {
+					t.Errorf("GenOutputs() OutPath should not be empty for temp file")
+				}
+			}
+
+			// Check IntPath logic
+			if tt.wantIntPath != "" {
+				// Check exact IntPath match when specified
+				if result.IntPath != tt.wantIntPath {
+					t.Errorf("GenOutputs() IntPath = %v, want %v", result.IntPath, tt.wantIntPath)
+				}
+			} else if tt.wantOutExt != "" && !tt.wantDirectGen {
+				// Should have different IntPath for format conversion
+				if result.IntPath == result.OutPath {
+					t.Errorf("GenOutputs() IntPath should be different from OutPath when format conversion is needed")
+				}
+			} else if tt.conf.Mode == ModeRun && tt.wantOutExt == "" {
+				// Run mode without conversion should have same IntPath and OutPath
+				if result.IntPath != result.OutPath {
+					t.Errorf("GenOutputs() IntPath should equal OutPath for run mode without conversion")
+				}
+			} else if tt.conf.Mode == ModeInstall {
+				// Install mode: check based on whether it's device flashing or traditional install
+				isDeviceFlash := tt.conf.Target != "" || tt.wantOutExt != ""
+				if isDeviceFlash {
+					// Device flashing - should use temp files (like run mode)
+					if result.OutPath == "" {
+						// This is expected for temp files, no additional check needed
+					}
+				} else {
+					// Traditional install to BinPath - should have fixed paths
+					if result.IntPath != result.OutPath {
+						t.Errorf("GenOutputs() IntPath should equal OutPath for traditional install mode")
+					}
+				}
+			}
+		})
+	}
+}
+
+func TestDetermineFormat(t *testing.T) {
+	tests := []struct {
+		name     string
+		conf     *Config
+		emulator string
+		wantFmt  string
+		wantExt  string
+	}{
+		{
+			name:    "user specified format",
+			conf:    &Config{FileFormat: "hex"},
+			wantFmt: "hex",
+			wantExt: ".hex",
+		},
+		{
+			name:     "emulator format extraction",
+			conf:     &Config{Mode: ModeRun, Emulator: true},
+			emulator: "qemu-system-xtensa -machine esp32 -drive file={bin},if=mtd,format=raw",
+			wantFmt:  "bin",
+			wantExt:  ".bin",
+		},
+		{
+			name:    "no format",
+			conf:    &Config{},
+			wantFmt: "",
+			wantExt: "",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			gotFmt, gotExt := determineFormat(tt.conf, tt.emulator)
+			if gotFmt != tt.wantFmt {
+				t.Errorf("determineFormat() format = %v, want %v", gotFmt, tt.wantFmt)
+			}
+			if gotExt != tt.wantExt {
+				t.Errorf("determineFormat() ext = %v, want %v", gotExt, tt.wantExt)
+			}
+		})
+	}
+}
+
+func TestShouldDirectGen(t *testing.T) {
+	tests := []struct {
+		name   string
+		outExt string
+		binExt string
+		want   bool
+	}{
+		{"no extension", "", ".bin", true},
+		{"same extension", ".bin", ".bin", true},
+		{"img format", ".img", ".bin", true},
+		{"different extension", ".hex", ".bin", false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := shouldDirectGen(tt.outExt, tt.binExt); got != tt.want {
+				t.Errorf("shouldDirectGen() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestNeedsFwGen(t *testing.T) {
+	tests := []struct {
+		name   string
+		conf   *Config
+		outExt string
+		binExt string
+		want   bool
+	}{
+		{
+			name:   "build mode with file format",
+			conf:   &Config{Mode: ModeBuild, FileFormat: "hex"},
+			outExt: ".hex",
+			want:   true,
+		},
+		{
+			name:   "build mode without file format",
+			conf:   &Config{Mode: ModeBuild},
+			outExt: "",
+			want:   false,
+		},
+		{
+			name:   "run mode with emulator",
+			conf:   &Config{Mode: ModeRun, Emulator: true},
+			outExt: ".hex",
+			want:   true,
+		},
+		{
+			name:   "run mode with binExt",
+			conf:   &Config{Mode: ModeRun},
+			outExt: "",
+			binExt: ".bin",
+			want:   true,
+		},
+		{
+			name:   "test mode with emulator",
+			conf:   &Config{Mode: ModeTest, Emulator: true},
+			outExt: ".hex",
+			want:   true,
+		},
+		{
+			name:   "test mode with binExt",
+			conf:   &Config{Mode: ModeTest},
+			outExt: "",
+			binExt: ".bin",
+			want:   true,
+		},
+		{
+			name:   "cmptest mode with binExt",
+			conf:   &Config{Mode: ModeCmpTest},
+			outExt: "",
+			binExt: ".bin",
+			want:   true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := needsFwGen(tt.conf, tt.outExt, tt.binExt); got != tt.want {
+				t.Errorf("needsFwGen() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

internal/crosscompile/crosscompile.go

@@ -34,6 +34,7 @@ type Export struct {
 
 	BinaryFormat string // Binary format (e.g., "elf", "esp", "uf2")
 	FormatDetail string // For uf2, it's uf2FamilyID
+	Emulator     string // Emulator command template (e.g., "qemu-system-arm -M {} -kernel {}")
 }
 
 // URLs and configuration that can be overridden for testing
@@ -499,6 +500,7 @@ func useTarget(targetName string) (export Export, err error) {
 	export.ExtraFiles = config.ExtraFiles
 	export.BinaryFormat = config.BinaryFormat
 	export.FormatDetail = config.FormatDetail()
+	export.Emulator = config.Emulator
 
 	// Build environment map for template variable expansion
 	envs := buildEnvMap(env.LLGoROOT())

internal/firmware/firmware.go

@@ -20,6 +20,18 @@ func MakeFirmwareImage(infile, outfile, format, fmtDetail string) error {
 	return fmt.Errorf("unsupported firmware format: %s", format)
 }
 
+// ExtractFileFormatFromEmulator extracts file format from emulator command template
+// Returns the format if found (e.g. "bin", "hex", "zip", "img"), empty string if not found
+func ExtractFileFormatFromEmulator(emulatorCmd string) string {
+	formats := []string{"bin", "hex", "zip", "img", "uf2"}
+	for _, format := range formats {
+		if strings.Contains(emulatorCmd, "{"+format+"}") {
+			return format
+		}
+	}
+	return ""
+}
+
 // GetFileExtFromFormat converts file format to file extension
 func GetFileExtFromFormat(format string) string {
 	switch format {
@@ -33,6 +45,8 @@ func GetFileExtFromFormat(format string) string {
 		return ".uf2"
 	case "zip":
 		return ".zip"
+	case "img":
+		return ".img"
 	default:
 		return ""
 	}
@@ -47,7 +61,7 @@ func ConvertOutput(infile, outfile, binaryFormat, fileFormat string) error {
 		return nil
 	}
 
-	// Only support conversion to hex format
+	// Only support conversion to hex and format
 	if fileFormat == "hex" {
 		return convertToHex(infile, outfile)
 	}