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
LoadFirmware(const Uevent & uevent,const std::string & root,int fw_fd,size_t fw_size,int loading_fd,int data_fd)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
IsBooting()56 static bool IsBooting() {
57 return access("/dev/.booting", F_OK) == 0;
58 }
59
ProcessFirmwareEvent(const Uevent & uevent)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
HandleFirmwareEvent(const Uevent & uevent)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