tools/devshell/serial

#!/bin/bash
# Copyright 2019 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

#### CATEGORY=Device management
### attach to a serial console
## usage: fx serial [--output-file file] [--baud rate] [device-path]
##
## Options:
##   --output-file file      Record the serial output to the specified file.
##   --baud rate             Set the baud rate for the serial connection.
##                           Default is 115200.
##
## Note: Options above only work with physical devices, not supported for emulators.
##
## If no device path is given, a list of options will be presented.
##
## If the selected device is not readable by the active user account, it will
## first be chmod'd to provide access to the current user.
##
## Exit the session with CTRL+o
##
## In order to have arrow keys work, execute `export TERM=xterm; /boot/bin/sh`
## on in the console.

source "$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd)"/lib/vars.sh || exit $?
fx-config-read

function serial-emulator {
  fx-info "Assuming emulator already started with \`ffx emu start --headless\`"
  fx-command-run ffx emu console -s
  return $?
}

if ! which socat >/dev/null 2>&1; then
  fx-warn "The command \`socat\` was not found!"
  if [[ "$(uname)" == "Linux" ]]; then
    fx-warn "  If connecting to physical device, maybe \`apt install socat\`"
  else
    fx-error "Unsupported OS: $(uname)"
    exit 1
  fi
  fx-info "Trying to connect to emulator instead"
  serial-emulator
  exit $?
fi

pontis_message=""
if [[ -e "$(find_executable "pontis-pts")" ]]; then
  if pontis_serials="$(fx-command-run pontis-pts)"; then
    pontis_message="\nNo serial devices found on pontis"
    while IFS= read -r pontis_serial; do
      pontis_options+=("$pontis_serial")
    done <<<"$pontis_serials"
  fi
fi

BAUD_RATE=115200
DEVICE=""
OUTPUT_ARGS=()
# Separate output file from device path
while [[ $# -gt 0 ]]; do
  case "$1" in
    --output-file)
      # The next argument is the file path
      shift
      OUTPUT_ARGS=("-R" "$1")
      shift
      ;;
    --baud)
      shift
      BAUD_RATE="$1"
      shift
      ;;
    *)
      if [[ -z "$DEVICE" ]]; then
        DEVICE="$1"
      fi
      shift
      ;;
  esac
done

if [[ -z "$DEVICE" ]]; then
  options=($(find /dev -maxdepth 1 -name ttyUSB\* | sort))
  options+=("${pontis_options[@]}")
  if [[ "${#options}" = 0 ]]; then
    fx-warn "No ttyUSB* found in /dev${pontis_message}\nIf connecting to physical device, please specify any known path exactly."
    fx-info "Trying to connect to emulator instead"
    serial-emulator
    exit $?
  fi
  if [[ "${#options[@]}" -eq 1 ]]; then
    echo >&2 "Found one device at ${options[0]}"
    DEVICE="${options[0]}"
  elif [[ "${#options[@]}" -gt 1 ]]; then
    echo >&2 "Select a serial device from the following list:"
    select device in "${options[@]}"; do
      DEVICE="$device"
      break
    done
  fi
fi


if [[ ! -e "$DEVICE" ]]; then
  fx-error "$DEVICE not found"
  fx-info "Trying to connect to emulator instead"
  serial-emulator
  exit $?
fi

if [[ ! -r "$DEVICE" ]]; then
  if [[ "$(uname)" == "Linux" ]]; then
    owninggroup=$(stat "$DEVICE" --printf="%G")
    if [[ ! -r "$DEVICE" ]]; then
      fx-error "$DEVICE is not readable by $USER"
      fx-error " fix: sudo usermod -a -G "$owninggroup" $USER"
      fx-error "You need to start a new login session for a group change to take effect"
      exit 1
    fi
  else
    fx-error "Unsupported OS: $(uname)"
    exit 1
  fi
fi

echo >&2 "SERIAL: Connecting to $DEVICE..."
echo >&2 "SERIAL: Use CTRL-o to exit"
echo >&2 "SERIAL: Run: \`export TERM=xterm; /boot/bin/sh\` for improved key bindings"

# This is the method recommended in the socat manual to detect the presence /
# omission of this feature.
if $(socat -hh | grep ' ospeed' >/dev/null); then
  speed="ospeed=${BAUD_RATE},ispeed=${BAUD_RATE}"
else
  speed="b${BAUD_RATE}"
fi

exec socat "${OUTPUT_ARGS[@]}" -,sane,cfmakeraw,escape=0x0f "file:${DEVICE}",sane,cfmakeraw,"${speed}",cs8,parenb=0,cstopb=0,ixoff=0,ixon=0,crtscts=0,clocal=1,nonblock=1