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/*
* Copyright (C) 2017 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 "firmware_handler.h"
#include <fcntl.h>
#include <sys/sendfile.h>
#include <sys/wait.h>
#include <unistd.h>
#include <thread>
#include <android-base/chrono_utils.h>
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/unique_fd.h>
using android::base::Timer;
using android::base::unique_fd;
using android::base::WriteFully;
namespace android {
namespace init {
std::vector<std::string> firmware_directories;
static void LoadFirmware(const Uevent& uevent, const std::string& root, int fw_fd, size_t fw_size,
int loading_fd, int data_fd) {
// Start transfer.
WriteFully(loading_fd, "1", 1);
// Copy the firmware.
int rc = sendfile(data_fd, fw_fd, nullptr, fw_size);
if (rc == -1) {
PLOG(ERROR) << "firmware: sendfile failed { '" << root << "', '" << uevent.firmware
<< "' }";
}
// Tell the firmware whether to abort or commit.
const char* response = (rc != -1) ? "0" : "-1";
WriteFully(loading_fd, response, strlen(response));
}
static bool IsBooting() {
return access("/dev/.booting", F_OK) == 0;
}
static void ProcessFirmwareEvent(const Uevent& uevent) {
int booting = IsBooting();
LOG(INFO) << "firmware: loading '" << uevent.firmware << "' for '" << uevent.path << "'";
std::string root = "/sys" + uevent.path;
std::string loading = root + "/loading";
std::string data = root + "/data";
unique_fd loading_fd(open(loading.c_str(), O_WRONLY | O_CLOEXEC));
if (loading_fd == -1) {
PLOG(ERROR) << "couldn't open firmware loading fd for " << uevent.firmware;
return;
}
unique_fd data_fd(open(data.c_str(), O_WRONLY | O_CLOEXEC));
if (data_fd == -1) {
PLOG(ERROR) << "couldn't open firmware data fd for " << uevent.firmware;
return;
}
try_loading_again:
for (const auto& firmware_directory : firmware_directories) {
std::string file = firmware_directory + uevent.firmware;
unique_fd fw_fd(open(file.c_str(), O_RDONLY | O_CLOEXEC));
struct stat sb;
if (fw_fd != -1 && fstat(fw_fd, &sb) != -1) {
LoadFirmware(uevent, root, fw_fd, sb.st_size, loading_fd, data_fd);
return;
}
}
if (booting) {
// If we're not fully booted, we may be missing
// filesystems needed for firmware, wait and retry.
std::this_thread::sleep_for(100ms);
booting = IsBooting();
goto try_loading_again;
}
LOG(ERROR) << "firmware: could not find firmware for " << uevent.firmware;
// Write "-1" as our response to the kernel's firmware request, since we have nothing for it.
write(loading_fd, "-1", 2);
}
void HandleFirmwareEvent(const Uevent& uevent) {
if (uevent.subsystem != "firmware" || uevent.action != "add") return;
// Loading the firmware in a child means we can do that in parallel...
auto pid = fork();
if (pid == -1) {
PLOG(ERROR) << "could not fork to process firmware event for " << uevent.firmware;
}
if (pid == 0) {
Timer t;
ProcessFirmwareEvent(uevent);
LOG(INFO) << "loading " << uevent.path << " took " << t;
_exit(EXIT_SUCCESS);
}
}
} // namespace init
} // namespace android
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