blob: 67cac19144c153f7789cc4d2c2efda1e6c88625b [file] [log] [blame]
/*
* Copyright (C) 2020 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 "first_stage_console.h"
#include <stdio.h>
#include <sys/stat.h>
#include <sys/sysmacros.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <termios.h>
#include <string>
#include <thread>
#include <android-base/chrono_utils.h>
#include <android-base/file.h>
#include <android-base/logging.h>
static bool KernelConsolePresent(const std::string& cmdline) {
size_t pos = 0;
while (true) {
pos = cmdline.find("console=", pos);
if (pos == std::string::npos) return false;
if (pos == 0 || cmdline[pos - 1] == ' ') return true;
pos++;
}
}
static bool SetupConsole() {
if (mknod("/dev/console", S_IFCHR | 0600, makedev(5, 1))) {
PLOG(ERROR) << "unable to create /dev/console";
return false;
}
int fd = -1;
int tries = 50; // should timeout after 5s
// The device driver for console may not be ready yet so retry for a while in case of failure.
while (tries--) {
fd = open("/dev/console", O_RDWR);
if (fd != -1) break;
std::this_thread::sleep_for(100ms);
}
if (fd == -1) {
PLOG(ERROR) << "could not open /dev/console";
return false;
}
ioctl(fd, TIOCSCTTY, 0);
dup2(fd, STDIN_FILENO);
dup2(fd, STDOUT_FILENO);
dup2(fd, STDERR_FILENO);
close(fd);
return true;
}
static void RunScript() {
LOG(INFO) << "Attempting to run /first_stage.sh...";
pid_t pid = fork();
if (pid != 0) {
int status;
waitpid(pid, &status, 0);
LOG(INFO) << "/first_stage.sh exited with status " << status;
return;
}
const char* path = "/system/bin/sh";
const char* args[] = {path, "/first_stage.sh", nullptr};
int rv = execv(path, const_cast<char**>(args));
LOG(ERROR) << "unable to execv /first_stage.sh, returned " << rv << " errno " << errno;
}
namespace android {
namespace init {
void StartConsole(const std::string& cmdline) {
bool console = KernelConsolePresent(cmdline);
// Use a simple sigchld handler -- first_stage_console doesn't need to track or log zombies
const struct sigaction chld_act { .sa_handler = SIG_DFL, .sa_flags = SA_NOCLDWAIT };
sigaction(SIGCHLD, &chld_act, nullptr);
pid_t pid = fork();
if (pid != 0) {
int status;
waitpid(pid, &status, 0);
LOG(ERROR) << "console shell exited with status " << status;
return;
}
if (console) console = SetupConsole();
RunScript();
if (console) {
const char* path = "/system/bin/sh";
const char* args[] = {path, nullptr};
int rv = execv(path, const_cast<char**>(args));
LOG(ERROR) << "unable to execv, returned " << rv << " errno " << errno;
}
_exit(127);
}
int FirstStageConsole(const std::string& cmdline, const std::string& bootconfig) {
auto pos = bootconfig.find("androidboot.first_stage_console =");
if (pos != std::string::npos) {
int val = 0;
if (sscanf(bootconfig.c_str() + pos, "androidboot.first_stage_console = \"%d\"", &val) !=
1) {
return FirstStageConsoleParam::DISABLED;
}
if (val <= FirstStageConsoleParam::MAX_PARAM_VALUE && val >= 0) {
return val;
}
}
pos = cmdline.find("androidboot.first_stage_console=");
if (pos != std::string::npos) {
int val = 0;
if (sscanf(cmdline.c_str() + pos, "androidboot.first_stage_console=%d", &val) != 1) {
return FirstStageConsoleParam::DISABLED;
}
if (val <= FirstStageConsoleParam::MAX_PARAM_VALUE && val >= 0) {
return val;
}
}
return FirstStageConsoleParam::DISABLED;
}
} // namespace init
} // namespace android