--- /dev/null
+# Copyright 2020 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+# Let the user override the path to the simavr binary with the SIMAVR_PATH
+# environment variable.
+
+if { [info exists ::env(SIMAVR_PATH)] } {
+ set simavr_path $::env(SIMAVR_PATH)
+} else {
+ set simavr_path simavr
+}
+
+# Let the user override the simulated AVR chip with the SIMAVR_PATH environment
+# variable.
+#
+# The value passed here must be supported by avr-gcc (see the -mmcu flag in the
+# `AVR Options` section of the gcc(1) man page) and by simavr (see output of
+# `simavr --list-cores`).
+
+if { [info exists ::env(SIMAVR_MCU)] } {
+ set simavr_mcu $::env(SIMAVR_MCU)
+} else {
+ set simavr_mcu atmega2560
+}
+
+set simavr_last_load_file ""
+set simavr_spawn_id ""
+
+set_board_info compiler avr-gcc
+set_board_info c++compiler avr-g++
+
+set_board_info cflags "-mmcu=${simavr_mcu}"
+set_board_info ldflags "-mmcu=${simavr_mcu}"
+
+set_board_info use_gdb_stub 1
+set_board_info gdb_protocol "remote"
+set_board_info gdb,do_reload_on_run 1
+set_board_info noargs 1
+set_board_info gdb,noinferiorio 1
+set_board_info gdb,nofileio 1
+set_board_info gdb,noresults 1
+set_board_info gdb,nosignals 1
+
+proc gdb_load { file } {
+ global simavr_last_load_file
+ global simavr_spawn_id
+ global simavr_mcu
+ global simavr_path
+ global gdb_prompt
+
+ if { $file == "" } {
+ set file $simavr_last_load_file
+ } else {
+ set simavr_last_load_file $file
+ }
+
+ gdb_file_cmd $file
+
+ # Close any previous simavr instance.
+ if { $simavr_spawn_id != "" } {
+ close -i $simavr_spawn_id
+ set simavr_spawn_id ""
+ }
+
+ # Run simavr.
+ set cmd "spawn -noecho ${simavr_path} --mcu ${simavr_mcu} -g $file"
+ verbose -log "Spawning simavr: $cmd"
+ eval $cmd
+ set simavr_spawn_id $spawn_id
+ gdb_expect {
+ -i $simavr_spawn_id -re ".*avr_gdb_init listening on port 1234" {}
+ timeout { error "unable to start simavr" }
+ }
+
+ # Connect to simavr.
+ send_gdb "target remote :1234\n"
+ gdb_expect {
+ -re ".*Remote debugging using :1234.*\[\r\n\]+$gdb_prompt $" {}
+ timeout { error "unable to connect to simavr stub" }
+ }
+
+ return 0
+}