diff --git a/util/all_tests.go b/util/all_tests.go
index 38899bb..d361651 100644
--- a/util/all_tests.go
+++ b/util/all_tests.go
@@ -33,6 +33,7 @@
 
 var (
 	useValgrind     = flag.Bool("valgrind", false, "If true, run code under valgrind")
+	useCallgrind    = flag.Bool("callgrind", false, "If true, run code under valgrind to generate callgrind traces.")
 	useGDB          = flag.Bool("gdb", false, "If true, run BoringSSL code under gdb")
 	buildDir        = flag.String("build-dir", "build", "The build directory to run the tests from.")
 	numWorkers      = flag.Int("num-workers", 1, "Runs the given number of workers when testing.")
@@ -113,6 +114,14 @@
 	return exec.Command("valgrind", valgrindArgs...)
 }
 
+func callgrindOf(path string, args ...string) *exec.Cmd {
+	valgrindArgs := []string{"-q", "--tool=callgrind", "--dump-instr=yes", "--collect-jumps=yes", "--callgrind-out-file=" + *buildDir + "/callgrind/callgrind.out.%p"}
+	valgrindArgs = append(valgrindArgs, path)
+	valgrindArgs = append(valgrindArgs, args...)
+
+	return exec.Command("valgrind", valgrindArgs...)
+}
+
 func gdbOf(path string, args ...string) *exec.Cmd {
 	xtermArgs := []string{"-e", "gdb", "--args"}
 	xtermArgs = append(xtermArgs, path)
@@ -135,6 +144,8 @@
 	var cmd *exec.Cmd
 	if *useValgrind {
 		cmd = valgrindOf(false, prog, args...)
+	} else if *useCallgrind {
+		cmd = callgrindOf(prog, args...)
 	} else if *useGDB {
 		cmd = gdbOf(prog, args...)
 	} else {
diff --git a/util/generate-asm-lcov.py b/util/generate-asm-lcov.py
new file mode 100755
index 0000000..7b66070
--- /dev/null
+++ b/util/generate-asm-lcov.py
@@ -0,0 +1,149 @@
+#!/usr/bin/python
+# Copyright (c) 2016, Google Inc.
+#
+# Permission to use, copy, modify, and/or distribute this software for any
+# purpose with or without fee is hereby granted, provided that the above
+# copyright notice and this permission notice appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+# SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+# OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+import os
+import os.path
+import subprocess
+import sys
+
+# The LCOV output format for each source file is:
+#
+# SF:<filename>
+# DA:<line>,<execution count>
+# ...
+# end_of_record
+#
+# The <execution count> can either be 0 for an unexecuted instruction or a
+# value representing the number of executions. The DA line should be omitted
+# for lines not representing an instruction.
+
+SECTION_SEPERATOR = '-' * 80
+
+def is_asm(l):
+  """Returns whether a line should be considered to be an instruction."""
+  l = l.strip()
+  # Empty lines
+  if l == '':
+    return False
+  # Comments
+  if l.startswith('#'):
+    return False
+  # Assembly Macros
+  if l.startswith('.'):
+    return False
+  # Label
+  if l.endswith(':'):
+    return False
+  return True
+
+def merge(callgrind_files, srcs):
+  """Calls callgrind_annotate over the set of callgrind output
+  |callgrind_files| using the sources |srcs| and merges the results
+  together."""
+  out = ''
+  for file in callgrind_files:
+    data = subprocess.check_output(['callgrind_annotate', file] + srcs)
+    out += '%s\n%s\n' % (data, SECTION_SEPERATOR)
+  return out
+
+def parse(filename, data, current):
+  """Parses an annotated execution flow |data| from callgrind_annotate for
+  source |filename| and updates the current execution counts from |current|."""
+  with open(filename) as f:
+    source = f.read().split('\n')
+
+  out = current
+  if out == None:
+    out = [0 if is_asm(l) else None for l in source]
+
+  # Lines are of the following formats:
+  #   -- line: Indicates that analysis continues from a different place.
+  #   =>     : Indicates a call/jump in the control flow.
+  #   <Count> <Code>: Indicates that the line has been executed that many times.
+  line = None
+  for l in data:
+    l = l.strip() + ' '
+    if l.startswith('-- line'):
+      line = int(l.split(' ')[2]) - 1
+    elif line != None and '=>' not in l:
+      count = l.split(' ')[0].replace(',', '').replace('.', '0')
+      instruction = l.split(' ', 1)[1].strip()
+      if count != '0' or is_asm(instruction):
+        if out[line] == None:
+          out[line] = 0
+        out[line] += int(count)
+      line += 1
+
+  return out
+
+
+def generate(data):
+  """Parses the merged callgrind_annotate output |data| and generates execution
+  counts for all annotated files."""
+  out = {}
+  data = [p.strip() for p in data.split(SECTION_SEPERATOR)]
+
+
+  # Most sections are ignored, but a section with:
+  #  User-annotated source: <file>
+  # precedes a listing of execution count for that <file>.
+  for i in range(len(data)):
+    if 'User-annotated source' in data[i] and i < len(data) - 1:
+      filename = data[i].split(':', 1)[1].strip()
+      res = data[i + 1]
+      if filename not in out:
+        out[filename] = None
+      if 'No information' in res:
+        res = []
+      else:
+        res = res.split('\n')
+      out[filename] = parse(filename, res, out[filename])
+  return out
+
+def output(data):
+  """Takes a dictionary |data| of filenames and execution counts and generates
+  a LCOV coverage output."""
+  out = ''
+  for filename, counts in data.iteritems():
+    out += 'SF:%s\n' % (os.path.abspath(filename))
+    for line, count in enumerate(counts):
+      if count != None:
+        out += 'DA:%d,%s\n' % (line + 1, count)
+    out += 'end_of_record\n'
+  return out
+
+if __name__ == '__main__':
+  if len(sys.argv) != 3:
+    print '%s <Callgrind Folder> <Build Folder>' % (__file__)
+    sys.exit()
+
+  cg_folder = sys.argv[1]
+  build_folder = sys.argv[2]
+
+  cg_files = []
+  for (cwd, _, files) in os.walk(cg_folder):
+    for f in files:
+      if f.startswith('callgrind.out'):
+        cg_files.append(os.path.abspath(os.path.join(cwd, f)))
+
+  srcs = []
+  for (cwd, _, files) in os.walk(build_folder):
+    for f in files:
+      fn = os.path.join(cwd, f)
+      if fn.endswith('.S'):
+        srcs.append(fn)
+
+  annotated = merge(cg_files, srcs)
+  lcov = generate(annotated)
+  print output(lcov)
diff --git a/util/generate-coverage.sh b/util/generate-coverage.sh
new file mode 100755
index 0000000..2fbe6b8
--- /dev/null
+++ b/util/generate-coverage.sh
@@ -0,0 +1,60 @@
+#!/bin/sh
+# Copyright (c) 2016, Google Inc.
+#
+# Permission to use, copy, modify, and/or distribute this software for any
+# purpose with or without fee is hereby granted, provided that the above
+# copyright notice and this permission notice appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+# SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+# OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+set -xe
+
+SRC=$PWD
+
+BUILD=$(mktemp -d '/tmp/boringssl.XXXXXX')
+BUILD_SRC=$(mktemp -d '/tmp/boringssl-src.XXXXXX')
+LCOV=$(mktemp -d '/tmp/boringssl-lcov.XXXXXX')
+
+if [ -n "$1" ]; then
+  LCOV=$(readlink -f "$1")
+  mkdir -p "$LCOV"
+fi
+
+cd "$BUILD"
+cmake "$SRC" -GNinja -DCMAKE_C_FLAGS='-fprofile-arcs -ftest-coverage' \
+  -DCMAKE_CXX_FLAGS='-fprofile-arcs -ftest-coverage' -DCMAKE_ASM_FLAGS='-Wa,-g'
+ninja
+
+cp -r "$SRC/crypto" "$SRC/decrepit" "$SRC/include" "$SRC/ssl" "$SRC/tool" \
+  "$BUILD_SRC"
+cp -r "$BUILD"/* "$BUILD_SRC"
+mkdir "$BUILD/callgrind/"
+
+cd "$SRC"
+go run "$SRC/util/all_tests.go" -build-dir "$BUILD" -callgrind -num-workers 16
+util/generate-asm-lcov.py "$BUILD/callgrind" "$BUILD" > "$BUILD/asm.info"
+
+go run "util/all_tests.go" -build-dir "$BUILD"
+
+cd "$SRC/ssl/test/runner"
+go test -shim-path "$BUILD/ssl/test/bssl_shim" -num-workers 1
+
+cd "$LCOV"
+lcov -c -d "$BUILD" -b "$BUILD" -o "$BUILD/lcov.info"
+lcov -r "$BUILD/lcov.info" "*_test.c" -o "$BUILD/lcov-1.info"
+lcov -r "$BUILD/lcov-1.info" "*_test.cc" -o "$BUILD/lcov-2.info"
+cat "$BUILD/lcov-2.info" "$BUILD/asm.info" > "$BUILD/final.info"
+sed -i "s;$BUILD;$BUILD_SRC;g" "$BUILD/final.info"
+sed -i "s;$SRC;$BUILD_SRC;g" "$BUILD/final.info"
+genhtml -p "$BUILD_SRC" "$BUILD/final.info"
+
+rm -rf "$BUILD"
+rm -rf "$BUILD_SRC"
+
+xdg-open index.html