tools/debug-sd-boot.sh

   1 #!/usr/bin/env bash
   2 # SPDX-License-Identifier: LGPL-2.1-or-later
   3
   4 set -e
   5
   6 if [[ $# -lt 2 ]]; then
   7     echo "Usage: ${0} TARGET INPUT [GDBSCRIPT]"
   8     echo "Debug systemd-boot/stub in QEMU."
   9     echo
  10     echo "TARGET should point to the EFI binary to be examined inside the"
  11     echo "build directory (systemd-boot\$ARCH.efi or linux\$arch.efi.stub)."
  12     echo
  13     echo "INPUT should point to the QEMU serial output pipe. This is used to"
  14     echo "extract the location of the symbols. For this to work, QEMU must"
  15     echo "be run with '-s -serial pipe:PATH'. Note that QEMU will append"
  16     echo ".in/.out to the path, while this script expects the out pipe directly."
  17     echo
  18     echo "If GDBSCRIPT is empty, gdb is run directly attached to the boot"
  19     echo "loader, otherwise a script is generated in the given path that allows"
  20     echo "attaching manually like this:"
  21     echo "    (gdb) source GDBSCRIPT"
  22     echo "    (gdb) target remote :1234"
  23     echo
  24     echo "Example usage:"
  25     echo "    mkfifo /tmp/sdboot.{in,out}"
  26     echo "    qemu-system-x86_64 [...] -s -serial pipe:/tmp/sdboot"
  27     echo "    ./tools/debug-sd-boot.sh ./build/src/boot/efi/systemd-bootx64.efi \\"
  28     echo "        /tmp/sdboot.out"
  29     exit 1
  30 fi
  31
  32 binary=$(realpath "${1}")
  33 if [[ "${1}" =~ systemd-boot([[:alnum:]]+).efi ]]; then
  34     target="systemd-boot"
  35     symbols=$(realpath "${1%efi}elf")
  36 elif [[ "${1}" =~ linux([[:alnum:]]+).efi.stub ]]; then
  37     target="systemd-stub"
  38     symbols=$(realpath "${1%efi.stub}elf.stub")
  39 else
  40     echo "Cannot detect EFI binary '${1}'."
  41     exit 1
  42 fi
  43
  44 case "${BASH_REMATCH[1]}" in
  45     ia32) arch="i386";;
  46     x64)  arch="i386:x86-64";;
  47     aa64) arch="aarch64";;
  48     arm|riscv64) arch="${BASH_REMATCH[1]}";;
  49     *)
  50         echo "Unknown EFI arch '${BASH_REMATCH[1]}'."
  51         exit 1
  52 esac
  53
  54 # system-boot/stub will print out a line like this to inform us where it was loaded:
  55 #        systemd-boot@0xC0DE
  56 while read -r line; do
  57     if [[ "${line}" =~ ${target}@(0x[[:xdigit:]]+) ]]; then
  58         loaded_base="${BASH_REMATCH[1]}"
  59         break
  60     fi
  61 done <"${2}"
  62
  63 if [[ -z "${loaded_base}" ]]; then
  64     echo "Could not determine loaded image base."
  65     exit 1
  66 fi
  67
  68 if [[ -z "${3}" ]]; then
  69     gdb_script=$(mktemp /tmp/debug-sd-boot.XXXXXX.gdb)
  70     trap 'rm -f "${gdb_script}"' EXIT
  71 else
  72     gdb_script="${3}"
  73 fi
  74
  75 cat >"${gdb_script}" <<EOF
  76 file ${binary}
  77 symbol-file ${symbols} -o ${loaded_base}
  78 set architecture ${arch}
  79 EOF
  80
  81 if [[ -z "${3}" ]]; then
  82     gdb -x "${gdb_script}" -ex "target remote :1234"
  83 else
  84     echo "GDB script written to '${gdb_script}'."
  85 fi