UEFI EDK II, TPM minting, QEMU launcher and basic DHCP support

Test Plan:
You still need a recent version of QEMU and swtpm installed (these are not yet integrated)
Run `make launch` and have fun with a running Smalltown instance :)

X-Origin-Diff: phab/D159
GitOrigin-RevId: c7245bfbabebf92507445525bee009a71d19caea
diff --git a/pkg/sysfs/uevents.go b/pkg/sysfs/uevents.go
new file mode 100644
index 0000000..fed4319
--- /dev/null
+++ b/pkg/sysfs/uevents.go
@@ -0,0 +1,50 @@
+// Copyright 2020 The Monogon Project Authors.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package sysfs
+
+import (
+	"bufio"
+	"io"
+	"os"
+	"strings"
+)
+
+func ReadUevents(filename string) (map[string]string, error) {
+	f, err := os.Open(filename)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	ueventMap := make(map[string]string)
+	reader := bufio.NewReader(f)
+	for {
+		name, err := reader.ReadString(byte('='))
+		if err == io.EOF {
+			break
+		} else if err != nil {
+			return nil, err
+		}
+		value, err := reader.ReadString(byte('\n'))
+		if err == io.EOF {
+			continue
+		} else if err != nil {
+			return nil, err
+		}
+		ueventMap[strings.Trim(name, "=")] = strings.TrimSpace(value)
+	}
+	return ueventMap, nil
+}