compiler: produce .hex files directly

main.go

@@ -89,6 +89,7 @@ func Compile(pkgName, runtimePath, outpath, target string, printIR, dumpSSA bool
 
 		// Link the object file with the system compiler.
 		executable := filepath.Join(dir, "main")
+		tmppath := executable // final file
 		args := append(spec.PreLinkArgs, "-o", executable, objfile)
 		cmd := exec.Command(spec.Linker, args...)
 		cmd.Stdout = os.Stdout
@@ -98,9 +99,21 @@ func Compile(pkgName, runtimePath, outpath, target string, printIR, dumpSSA bool
 			return err
 		}
 
-		if err := os.Rename(executable, outpath); err != nil {
+		if strings.HasSuffix(outpath, ".hex") {
+			// Get an Intel .hex file from the .elf file.
+			tmppath = filepath.Join(dir, "main.hex")
+			cmd := exec.Command(spec.Objcopy, "-O", "ihex", executable, tmppath)
+			cmd.Stdout = os.Stdout
+			cmd.Stderr = os.Stderr
+			err = cmd.Run()
+			if err != nil {
+				return err
+			}
+		}
+
+		if err := os.Rename(tmppath, outpath); err != nil {
 			// Moving failed. Do a file copy.
-			inf, err := os.Open(executable)
+			inf, err := os.Open(tmppath)
 			if err != nil {
 				return err
 			}

target.go

@@ -18,6 +18,7 @@ type TargetSpec struct {
 	BuildTags   []string `json:"build-tags"`
 	Linker      string   `json:"linker"`
 	PreLinkArgs []string `json:"pre-link-args"`
+	Objcopy     string   `json:"objcopy"`
 }
 
 // Load a target specification
@@ -26,6 +27,7 @@ func LoadTarget(target string) (*TargetSpec, error) {
 		Triple:    target,
 		BuildTags: []string{runtime.GOOS, runtime.GOARCH},
 		Linker:    "cc",
+		Objcopy:   "objcopy",
 	}
 
 	// See whether there is a target specification for this target (e.g.

targets/arduino.json

@@ -2,5 +2,6 @@
 	"llvm-target": "avr-atmel-none",
 	"build-tags": ["avr", "avr8", "atmega", "atmega328p", "js", "wasm"],
 	"linker": "avr-gcc",
-	"pre-link-args": ["-nostdlib", "-T", "targets/avr.ld", "-Wl,--gc-sections", "targets/avr.S"]
+	"pre-link-args": ["-nostdlib", "-T", "targets/avr.ld", "-Wl,--gc-sections", "targets/avr.S"],
+	"objcopy": "avr-objcopy"
 }

targets/pca10040.json

@@ -2,5 +2,6 @@
 	"llvm-target": "armv7m-none-eabi",
 	"build-tags": ["nrf", "nrf52", "nrf52832", "js", "wasm"],
 	"linker": "arm-none-eabi-gcc",
-	"pre-link-args": ["-nostdlib", "-nostartfiles", "-mcpu=cortex-m4", "-mthumb", "-T", "targets/arm.ld", "-Wl,--gc-sections", "-fno-exceptions", "-fno-unwind-tables", "-ffunction-sections", "-fdata-sections", "-Os", "-DNRF52832_XXAA", "-D__STARTUP_CLEAR_BSS", "-Ilib/CMSIS/CMSIS/Include", "lib/nrfx/mdk/gcc_startup_nrf51.S", "lib/nrfx/mdk/system_nrf52.c"]
+	"pre-link-args": ["-nostdlib", "-nostartfiles", "-mcpu=cortex-m4", "-mthumb", "-T", "targets/arm.ld", "-Wl,--gc-sections", "-fno-exceptions", "-fno-unwind-tables", "-ffunction-sections", "-fdata-sections", "-Os", "-DNRF52832_XXAA", "-D__STARTUP_CLEAR_BSS", "-Ilib/CMSIS/CMSIS/Include", "lib/nrfx/mdk/gcc_startup_nrf51.S", "lib/nrfx/mdk/system_nrf52.c"],
+	"objcopy": "arm-none-eabi-objcopy"
 }