From 35e0f6d290ea7c12164bcfaf1b857d965e943938 Mon Sep 17 00:00:00 2001
From: Tao Bao <tbao@google.com>
Date: Thu, 16 May 2019 14:42:42 -0700
Subject: Add misc_writer.

bootloader_message.h currently divides /misc into four segments. The
space between 2K and 16K is reserved for vendor use (e.g. bootloader
persists flags). This CL adds a vendor tool "misc_writer", to allow
writing data to the vendor space in /misc, before getting a dedicated
HAL for accessing /misc partition (b/131775112).

Targets need to explicitly include the module, then invoke the
executable to write data. For example, the following command will write
3-byte data ("0xABCDEF") to offset 4 in vendor space (i.e. 2048 + 4 in
/misc).
$ /vendor/bin/misc_writer --vendor-space-offset 4 --hex-string 0xABCDEF

Bug: 132906936
Test: Run recovery_unit_test on crosshatch.
Test: Call the command via init.hardware.rc on crosshatch. Check that
      the call finishes successfully. Then check the contents written to
      /misc (`dd bs=1 skip=2048 if=/dev/block/sda2 count=32 | xxd`).
Change-Id: I79548fc63fc79b705a0320868690569c3106949f
Merged-In: I79548fc63fc79b705a0320868690569c3106949f
(cherry picked from commit 7ae01698424cc3adf635c324961b1405594f5156)
---
 misc_writer/misc_writer.cpp | 106 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 106 insertions(+)
 create mode 100644 misc_writer/misc_writer.cpp

(limited to 'misc_writer/misc_writer.cpp')

diff --git a/misc_writer/misc_writer.cpp b/misc_writer/misc_writer.cpp
new file mode 100644
index 000000000..1d9702ebf
--- /dev/null
+++ b/misc_writer/misc_writer.cpp
@@ -0,0 +1,106 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * 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.
+ */
+
+#include <errno.h>
+#include <getopt.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <iostream>
+#include <string>
+#include <string_view>
+#include <vector>
+
+#include <android-base/logging.h>
+#include <android-base/parseint.h>
+#include <bootloader_message/bootloader_message.h>
+
+using namespace std::string_literals;
+
+static std::vector<uint8_t> ParseHexString(std::string_view hex_string) {
+  auto length = hex_string.size();
+  if (length % 2 != 0 || length == 0) {
+    return {};
+  }
+
+  std::vector<uint8_t> result(length / 2);
+  for (size_t i = 0; i < length / 2; i++) {
+    auto sub = "0x" + std::string(hex_string.substr(i * 2, 2));
+    if (!android::base::ParseUint(sub, &result[i])) {
+      return {};
+    }
+  }
+  return result;
+}
+
+static int Usage(std::string_view name) {
+  std::cerr << name << " usage:\n";
+  std::cerr << name << " [--vendor-space-offset <offset>] --hex-string 0xABCDEF\n";
+  std::cerr << "Writes the given hex string to the specified offset in vendor space in /misc "
+               "partition. Offset defaults to 0 if unspecified.\n";
+  return EXIT_FAILURE;
+}
+
+// misc_writer is a vendor tool that writes data to the vendor space in /misc.
+int main(int argc, char** argv) {
+  constexpr struct option OPTIONS[] = {
+    { "vendor-space-offset", required_argument, nullptr, 0 },
+    { "hex-string", required_argument, nullptr, 0 },
+    { nullptr, 0, nullptr, 0 },
+  };
+
+  // Offset defaults to 0 if unspecified.
+  size_t offset = 0;
+  std::string_view hex_string;
+
+  int arg;
+  int option_index;
+  while ((arg = getopt_long(argc, argv, "", OPTIONS, &option_index)) != -1) {
+    if (arg != 0) {
+      LOG(ERROR) << "Invalid command argument";
+      return Usage(argv[0]);
+    }
+    auto option_name = OPTIONS[option_index].name;
+    if (option_name == "vendor-space-offset"s) {
+      if (!android::base::ParseUint(optarg, &offset)) {
+        LOG(ERROR) << "Failed to parse the offset: " << optarg;
+        return Usage(argv[0]);
+      }
+    } else if (option_name == "hex-string"s) {
+      hex_string = optarg;
+    }
+  }
+
+  if (hex_string.starts_with("0x") || hex_string.starts_with("0X")) {
+    hex_string = hex_string.substr(2);
+  }
+  if (hex_string.empty()) {
+    LOG(ERROR) << "Invalid input hex string: " << hex_string;
+    return Usage(argv[0]);
+  }
+
+  auto data = ParseHexString(hex_string);
+  if (data.empty()) {
+    LOG(ERROR) << "Failed to parse the input hex string: " << hex_string;
+    return EXIT_FAILURE;
+  }
+  if (std::string err; !WriteMiscPartitionVendorSpace(data.data(), data.size(), offset, &err)) {
+    LOG(ERROR) << "Failed to write to misc partition: " << err;
+    return EXIT_FAILURE;
+  }
+  return EXIT_SUCCESS;
+}
-- 
cgit v1.2.3