first cut: establishes base helper classes and main

bootloader_type.cc

+// Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// BootloaderType implementation
+
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+
+#include <string>
+
+#include "bootloader_type.h"
+
+namespace cros_boot_mode {
+
+const char *BootloaderType::kBootloaderTypeText[] = {
+ "chromeos",  // cros_fw (any platform)
+ "efi",  // cros_efi
+ "legacy",  // cros_legacy
+ "debug",  // cros_debug (cros_fw with developer override)
+};
+const size_t BootloaderType::kBootloaderTypeCount =
+  sizeof(kBootloaderTypeText) / sizeof(*kBootloaderTypeText);
+// These values are expected to be found in the kernel commandline with space
+// or '\0' word boundaries.  The ordering of this array must correspond to
+// the array above and the defined enum.
+const char *BootloaderType::kSupportedBootloaders[] = {
+  "cros_secure",
+  "cros_efi",
+  "cros_legacy",
+  "cros_debug",
+};
+
+const int BootloaderType::kMaxKernelCmdlineSize = 4096;  // one page.
+
+BootloaderType::BootloaderType()  { }
+BootloaderType::~BootloaderType() { }
+
+// This function looks for given argument space or nul delimited in
+// a /proc/cmdline style char array. See bootloader_type.h for details.
+int BootloaderType::Process(const char *contents, size_t length) {
+  if (!length || !contents)
+    return kUnsupported;
+
+  static const char kDelimiter = ' ';
+  static const char kTerminal = '\0';
+  for (unsigned i = 0; i < kBootloaderTypeCount; ++i) {
+    const char *candidate = kSupportedBootloaders[i];
+    const char *start = strstr(contents, candidate);
+    while (start) {
+      const char *end = start + strlen(candidate);
+      if ((*end == kTerminal || *end == kDelimiter) &&
+          (start == contents || *(start - 1) == kDelimiter))
+        return i;
+      start = strstr(end, candidate);
+    }
+  }
+  return kUnsupported;
+}
+
+}  // namespace cros_boot_mode