Merge changes from topic "misctrl" into main

* changes:
  misctrl: read message, incl 16kb flag
  intro misctrl

bootloader_message/Android.bp

@@ -39,6 +39,17 @@ cc_defaults {
     export_include_dirs: ["include"],
 }
 
+cc_binary {
+    name: "misctrl",
+    shared_libs: [
+        "libbase",
+        "libbootloader_message",
+        "liblog",
+    ],
+    init_rc: ["misctrl.rc"],
+    srcs: ["misctrl_main.cpp"],
+}
+
 cc_library {
     name: "libbootloader_message",
     defaults: [

bootloader_message/bootloader_message.cpp

@@ -26,6 +26,7 @@
 #include <vector>
 
 #include <android-base/file.h>
+#include <android-base/hex.h>
 #include <android-base/properties.h>
 #include <android-base/stringprintf.h>
 #include <android-base/unique_fd.h>
@@ -324,6 +325,33 @@ bool WriteMiscKcmdlineMessage(const misc_kcmdline_message& message, std::string*
                                        offsetof(misc_system_space_layout, kcmdline_message), err);
 }
 
+bool ReadMiscControlMessage(misc_control_message* message, std::string* err) {
+  return ReadMiscPartitionSystemSpace(message, sizeof(*message),
+                                      offsetof(misc_system_space_layout, control_message), err);
+}
+
+bool WriteMiscControlMessage(const misc_control_message& message, std::string* err) {
+  return WriteMiscPartitionSystemSpace(&message, sizeof(message),
+                                       offsetof(misc_system_space_layout, control_message), err);
+}
+
+bool CheckReservedSystemSpaceEmpty(bool* empty, std::string* err) {
+  constexpr size_t kReservedSize = SYSTEM_SPACE_SIZE_IN_MISC - sizeof(misc_system_space_layout);
+
+  uint8_t space[kReservedSize];
+  if (!ReadMiscPartitionSystemSpace(&space, kReservedSize, sizeof(misc_system_space_layout), err)) {
+    return false;
+  }
+
+  *empty = space[0] == 0 && 0 == memcmp(space, space + 1, kReservedSize - 1);
+
+  if (!*empty) {
+    *err = android::base::HexString(space, kReservedSize);
+  }
+
+  return true;
+}
+
 extern "C" bool write_reboot_bootloader(void) {
   std::string err;
   return write_reboot_bootloader(&err);

bootloader_message/include/bootloader_message/bootloader_message.h

@@ -107,6 +107,14 @@ struct misc_kcmdline_message {
   uint8_t reserved[51];
 } __attribute__((packed));
 
+// holds generic platform info, managed by misctrl
+struct misc_control_message {
+  uint8_t version;
+  uint32_t magic;
+  uint64_t misctrl_flags;
+  uint8_t reserved[51];
+} __attribute__((packed));
+
 #define MISC_VIRTUAL_AB_MESSAGE_VERSION 2
 #define MISC_VIRTUAL_AB_MAGIC_HEADER 0x56740AB0
 
@@ -127,6 +135,10 @@ struct misc_kcmdline_message {
 #define MISC_KCMDLINE_MAGIC_HEADER 0x6ab5110c
 #define MISC_KCMDLINE_BINDER_RUST 0x1
 
+#define MISC_CONTROL_MESSAGE_VERSION 1
+#define MISC_CONTROL_MAGIC_HEADER 0x736d6f72
+#define MISC_CONTROL_16KB_BEFORE 0x1
+
 #if (__STDC_VERSION__ >= 201112L) || defined(__cplusplus)
 static_assert(sizeof(struct misc_virtual_ab_message) == 64,
               "struct misc_virtual_ab_message has wrong size");
@@ -134,6 +146,8 @@ static_assert(sizeof(struct misc_memtag_message) == 64,
               "struct misc_memtag_message has wrong size");
 static_assert(sizeof(struct misc_kcmdline_message) == 64,
               "struct misc_kcmdline_message has wrong size");
+static_assert(sizeof(struct misc_control_message) == 64,
+              "struct misc_control_message has wrong size");
 #endif
 
 // This struct is not meant to be used directly, rather, it is to make
@@ -142,8 +156,14 @@ struct misc_system_space_layout {
   misc_virtual_ab_message virtual_ab_message;
   misc_memtag_message memtag_message;
   misc_kcmdline_message kcmdline_message;
+  misc_control_message control_message;
 } __attribute__((packed));
 
+#if (__STDC_VERSION__ >= 201112L) || defined(__cplusplus)
+static_assert(sizeof(struct misc_system_space_layout) % 64 == 0,
+              "prefer to extend by 64 byte chunks, for consistency");
+#endif
+
 #ifdef __cplusplus
 
 #include <string>
@@ -216,6 +236,14 @@ bool WriteMiscMemtagMessage(const misc_memtag_message& message, std::string* err
 // Read or write the kcmdline message from system space in /misc.
 bool ReadMiscKcmdlineMessage(misc_kcmdline_message* message, std::string* err);
 bool WriteMiscKcmdlineMessage(const misc_kcmdline_message& message, std::string* err);
+
+// Read or write the kcmdline message from system space in /misc.
+bool ReadMiscControlMessage(misc_control_message* message, std::string* err);
+bool WriteMiscControlMessage(const misc_control_message& message, std::string* err);
+
+// Check reserved system space.
+bool CheckReservedSystemSpaceEmpty(bool* empty, std::string* err);
+
 #else
 
 #include <stdbool.h>

bootloader_message/misctrl.rc

@@ -0,0 +1,4 @@
+service misctrl /system/bin/misctrl
+    user root # for misc partition access
+    class core
+    oneshot

bootloader_message/misctrl_main.cpp

@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2024 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 <android-base/properties.h>
+#include <bootloader_message/bootloader_message.h>
+#include <log/log.h>
+
+#include <string>
+
+#include <cstdio>
+
+static void log(const char* fmt, ...) __attribute__((format(printf, 1, 2)));
+static void log(const char* fmt, ...) {
+  va_list va;
+  va_start(va, fmt);
+
+  va_list vb;
+  va_copy(vb, va);
+
+  __android_log_vprint(ANDROID_LOG_ERROR, "misctrl", fmt, va);
+  va_end(va);
+
+  vfprintf(stderr, fmt, vb);
+  fprintf(stderr, "\n");
+  va_end(vb);
+}
+
+static int check_control_message() {
+  misc_control_message m;
+  std::string err;
+  if (!ReadMiscControlMessage(&m, &err)) {
+    log("Could not read misctrl message: %s", err.c_str());
+    return 1;
+  }
+
+  if (m.magic != MISC_CONTROL_MAGIC_HEADER || m.version != MISC_CONTROL_MESSAGE_VERSION) {
+    log("misctrl message invalid, resetting it");
+    m = { .version = MISC_CONTROL_MESSAGE_VERSION,
+          .magic = MISC_CONTROL_MAGIC_HEADER,
+          .misctrl_flags = 0 };
+  }
+
+  int res = 0;
+
+  const size_t ps = getpagesize();
+
+  if (ps != 4096 && ps != 16384) {
+    log("Unrecognized page size: %zu", ps);
+    res = 1;
+  }
+
+  if (ps == 16384) {
+    m.misctrl_flags |= MISC_CONTROL_16KB_BEFORE;
+  }
+
+  bool before_16kb = m.misctrl_flags & MISC_CONTROL_16KB_BEFORE;
+  res |= android::base::SetProperty("ro.misctrl.16kb_before", before_16kb ? "1" : "0");
+
+  if (!WriteMiscControlMessage(m, &err)) {
+    log("Could not write misctrl message: %s", err.c_str());
+    res |= 1;
+  }
+
+  return res;
+}
+
+static int check_reserved_space() {
+  bool empty;
+  std::string err;
+  bool success = CheckReservedSystemSpaceEmpty(&empty, &err);
+  if (!success) {
+    log("Could not read reserved space: %s", err.c_str());
+    return 1;
+  }
+  log("System reserved space empty? %d.", empty);
+
+  if (!err.empty()) {
+    constexpr size_t kPrintChunkSize = 256;
+    for (size_t i = 0; i < err.size(); i += kPrintChunkSize) {
+      log("DATA: %s", err.substr(i, kPrintChunkSize).c_str());
+    }
+  }
+
+  return empty ? 0 : 1;
+}
+
+int main() {
+  int err = 0;
+  err |= check_control_message();
+  err |= check_reserved_space();
+  return err;
+}