1 /* 2 * Copyright (C) 2017 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include "firmware_handler.h" 18 19 #include <fcntl.h> 20 #include <sys/sendfile.h> 21 #include <sys/wait.h> 22 #include <unistd.h> 23 24 #include <string> 25 #include <thread> 26 27 #include <android-base/chrono_utils.h> 28 #include <android-base/file.h> 29 #include <android-base/logging.h> 30 #include <android-base/unique_fd.h> 31 32 using android::base::Timer; 33 using android::base::unique_fd; 34 using android::base::WriteFully; 35 36 namespace android { 37 namespace init { 38 39 static void LoadFirmware(const Uevent& uevent, const std::string& root, int fw_fd, size_t fw_size, 40 int loading_fd, int data_fd) { 41 // Start transfer. 42 WriteFully(loading_fd, "1", 1); 43 44 // Copy the firmware. 45 int rc = sendfile(data_fd, fw_fd, nullptr, fw_size); 46 if (rc == -1) { 47 PLOG(ERROR) << "firmware: sendfile failed { '" << root << "', '" << uevent.firmware 48 << "' }"; 49 } 50 51 // Tell the firmware whether to abort or commit. 52 const char* response = (rc != -1) ? "0" : "-1"; 53 WriteFully(loading_fd, response, strlen(response)); 54 } 55 56 static bool IsBooting() { 57 return access("/dev/.booting", F_OK) == 0; 58 } 59 60 static void ProcessFirmwareEvent(const Uevent& uevent) { 61 int booting = IsBooting(); 62 63 LOG(INFO) << "firmware: loading '" << uevent.firmware << "' for '" << uevent.path << "'"; 64 65 std::string root = "/sys" + uevent.path; 66 std::string loading = root + "/loading"; 67 std::string data = root + "/data"; 68 69 unique_fd loading_fd(open(loading.c_str(), O_WRONLY | O_CLOEXEC)); 70 if (loading_fd == -1) { 71 PLOG(ERROR) << "couldn't open firmware loading fd for " << uevent.firmware; 72 return; 73 } 74 75 unique_fd data_fd(open(data.c_str(), O_WRONLY | O_CLOEXEC)); 76 if (data_fd == -1) { 77 PLOG(ERROR) << "couldn't open firmware data fd for " << uevent.firmware; 78 return; 79 } 80 81 static const char* firmware_dirs[] = {"/etc/firmware/", "/odm/firmware/", 82 "/vendor/firmware/", "/firmware/image/"}; 83 84 try_loading_again: 85 for (size_t i = 0; i < arraysize(firmware_dirs); i++) { 86 std::string file = firmware_dirs[i] + uevent.firmware; 87 unique_fd fw_fd(open(file.c_str(), O_RDONLY | O_CLOEXEC)); 88 struct stat sb; 89 if (fw_fd != -1 && fstat(fw_fd, &sb) != -1) { 90 LoadFirmware(uevent, root, fw_fd, sb.st_size, loading_fd, data_fd); 91 return; 92 } 93 } 94 95 if (booting) { 96 // If we're not fully booted, we may be missing 97 // filesystems needed for firmware, wait and retry. 98 std::this_thread::sleep_for(100ms); 99 booting = IsBooting(); 100 goto try_loading_again; 101 } 102 103 LOG(ERROR) << "firmware: could not find firmware for " << uevent.firmware; 104 105 // Write "-1" as our response to the kernel's firmware request, since we have nothing for it. 106 write(loading_fd, "-1", 2); 107 } 108 109 void HandleFirmwareEvent(const Uevent& uevent) { 110 if (uevent.subsystem != "firmware" || uevent.action != "add") return; 111 112 // Loading the firmware in a child means we can do that in parallel... 113 auto pid = fork(); 114 if (pid == -1) { 115 PLOG(ERROR) << "could not fork to process firmware event for " << uevent.firmware; 116 } 117 if (pid == 0) { 118 Timer t; 119 ProcessFirmwareEvent(uevent); 120 LOG(INFO) << "loading " << uevent.path << " took " << t; 121 _exit(EXIT_SUCCESS); 122 } 123 } 124 125 } // namespace init 126 } // namespace android 127