Monitor connects to the given port and reads/writes the serial port.
(executable, port string, config *compileopts.Config)
| 27 | |
| 28 | // Monitor connects to the given port and reads/writes the serial port. |
| 29 | func Monitor(executable, port string, config *compileopts.Config) error { |
| 30 | const timeout = time.Second * 3 |
| 31 | var exit func() // function to be called before exiting |
| 32 | var serialConn io.ReadWriter |
| 33 | |
| 34 | if config.Options.Serial == "rtt" { |
| 35 | // Use the RTT interface, which is documented (in part) here: |
| 36 | // https://wiki.segger.com/RTT |
| 37 | |
| 38 | // Try to find the "_SEGGER_RTT" symbol (machine.rttSerialInstance) |
| 39 | // symbol, which is the RTT control block. |
| 40 | file, err := elf.Open(executable) |
| 41 | if err != nil { |
| 42 | return fmt.Errorf("could not open ELF file to determine RTT control block: %w", err) |
| 43 | } |
| 44 | defer file.Close() |
| 45 | symbols, err := file.Symbols() |
| 46 | if err != nil { |
| 47 | return fmt.Errorf("could not read ELF symbol table to determine RTT control block: %w", err) |
| 48 | } |
| 49 | var address uint64 |
| 50 | for _, symbol := range symbols { |
| 51 | if symbol.Name == "_SEGGER_RTT" { |
| 52 | address = symbol.Value |
| 53 | break |
| 54 | } |
| 55 | } |
| 56 | if address == 0 { |
| 57 | return fmt.Errorf("could not find RTT control block in ELF file") |
| 58 | } |
| 59 | |
| 60 | // Start an openocd process in the background. |
| 61 | args, err := config.OpenOCDConfiguration() |
| 62 | if err != nil { |
| 63 | return err |
| 64 | } |
| 65 | args = append(args, |
| 66 | "-c", fmt.Sprintf("rtt setup 0x%x 16 \"SEGGER RTT\"", address), |
| 67 | "-c", "init", |
| 68 | "-c", "rtt server start 0 0") |
| 69 | cmd := executeCommand(config.Options, "openocd", args...) |
| 70 | stderr, err := cmd.StderrPipe() |
| 71 | if err != nil { |
| 72 | return err |
| 73 | } |
| 74 | cmd.Stdout = os.Stdout |
| 75 | err = cmd.Start() |
| 76 | if err != nil { |
| 77 | return err |
| 78 | } |
| 79 | defer cmd.Process.Kill() |
| 80 | exit = func() { |
| 81 | // Make sure the openocd process is terminated at exit. |
| 82 | // This does not happen through the defer above when exiting through |
| 83 | // os.Exit. |
| 84 | cmd.Process.Kill() |
| 85 | } |
| 86 |
no test coverage detected