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 '${BASH_REMATCH[1]}'."
  51         exit 1
  52 esac
  53
  54 # system-boot will print out a line like this to inform us where gdb is supposed to
  55 # look for .text and .data section:
  56 #        systemd-boot@0x0,0x0
  57 while read -r line; do
  58     if [[ "${line}" =~ ${target}@(0x[[:xdigit:]]+),(0x[[:xdigit:]]+) ]]; then
  59         text="${BASH_REMATCH[1]}"
  60         data="${BASH_REMATCH[2]}"
  61         break
  62     fi
  63 done <"${2}"
  64
  65 if [[ -z "${text}" || -z "${data}" ]]; then
  66     echo "Could not determine text and data location."
  67     exit 1
  68 fi
  69
  70 if [[ -z "${3}" ]]; then
  71     gdb_script=$(mktemp /tmp/debug-sd-boot.XXXXXX.gdb)
  72     trap 'rm -f "${gdb_script}"' EXIT
  73 else
  74     gdb_script="${3}"
  75 fi
  76
  77 echo "file ${binary}
  78 add-symbol-file ${symbols} ${text} -s .data ${data}
  79 set architecture ${arch}" > "${gdb_script}"
  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