tracing: create trace2line

This lead to a re-factoring of count boot instructions, since trace2line
relies on the same tracing mechanism.

Also, now that we have common factored, I've decided to put the traces on
the out dir, to concentrate all outputs in a single place, and allow
easy switching between archs.

trace-boot

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+set -eu
+. common
+arch=x86_64
+while getopts a: OPT; do
+  case "$OPT" in
+    a)
+      arch="$OPTARG"
+      ;;
+  esac
+done
+set_common_vars "$arch" false
+time ./run -a "$arch" -e 'init=/poweroff.out' -- -trace exec_tb,file="${lkmc_out_dir}/trace.bin"
+time ./qemu/scripts/simpletrace.py "${out_dir}/build/host-qemu-custom/trace-events-all" "${lkmc_out_dir}/trace.bin" >"${lkmc_out_dir}/trace.txt"
+
+# Instruction count.
+# We could put this on a separate script, but it just adds more arch boilerplate to a new script.
+# So let's just leave it here for now since it did not add a significant processing time.
+echo "instruction count all: $(wc -l "${lkmc_out_dir}/trace.txt" | cut -d' ' -f1)"
+entry_addr=$("${out_dir}"/host/bin/*-buildroot-*-readelf -h "${out_dir}/build/linux-custom/vmlinux" | grep 'Entry point address' | sed -E 's/.*: *//')
+echo "entry address: ${entry_addr}"
+sed "/${entry_addr}/q" "${lkmc_out_dir}/trace.txt" >"${lkmc_out_dir}/trace-boot.txt"
+echo "instruction count firmware: $(wc -l "${lkmc_out_dir}/trace-boot.txt" | cut -d' ' -f1)"