tc: create helper to access toolchain tools

rungdb-user

@@ -3,7 +3,6 @@ set -eu
 . common
 set -- ${cli_rungdb_user:-} "$@"
 usage="$0 <exec-relative-path> [<brk-symbol>]"
-gem5=false
 gem5_opt=
 while getopts a:gh OPT; do
   case "$OPT" in
@@ -34,8 +33,7 @@ else
 fi
 set_common_vars "$arch" "$gem5"
 executable="${build_dir}/${executable_rel}"
-readelf="${host_dir}/usr/bin/${arch}-linux-readelf"
-addr="$("$readelf" -h "$executable" | awk '/Entry/{ print $NF }' )"
+addr="$("${root_dir}/runtc" readelf -h "$executable" | awk '/Entry/{ print $NF }' )"
 ex="-ex \"add-symbol-file $executable $addr\""
 # -L or else lx-symbols throws for arm:
 # gdb.MemoryError: Cannot access memory at address 0xbf0040cc