2024年5月5日发(作者：)

if (is_first_stage) {

boot_clock::time_point start_time = boot_clock::now();

// Clear the umask.

umask(0);

// Get the basic filesystem setup we need put together in the initramdisk

// on / and then we'll let the rc file figure out the rest.

mount("tmpfs", "/dev", "tmpfs", MS_NOSUID, "mode=0755");

mkdir("/dev/pts", 0755);

mkdir("/dev/socket", 0755);

mount("devpts", "/dev/pts", "devpts", 0, NULL);

#define MAKE_STR(x) __STRING(x)

mount("proc", "/proc", "proc", 0, "hidepid=2,gid=" MAKE_STR(AID_READPROC));

// Don't expose the raw commandline to unprivileged processes.

chmod("/proc/cmdline", 0440);

gid_t groups[] = { AID_READPROC };

setgroups(arraysize(groups), groups);

mount("sysfs", "/sys", "sysfs", 0, NULL);

mount("selinuxfs", "/sys/fs/selinux", "selinuxfs", 0, NULL);

mknod("/dev/kmsg", S_IFCHR | 0600, makedev(1, 11));

mknod("/dev/random", S_IFCHR | 0666, makedev(1, 8));

mknod("/dev/urandom", S_IFCHR | 0666, makedev(1, 9));

// Now that tmpfs is mounted on /dev and we have /dev/kmsg, we can actually

// talk to the

InitKernelLogging(argv);

LOG(INFO) << "init first stage started!";

if (!DoFirstStageMount()) {

LOG(ERROR) << "Failed to mount required partitions early ...";

panic();

}

SetInitAvbVersionInRecovery();

// Set up SELinux, loading the SELinux policy.

selinux_initialize(true);

// We're in the kernel domain, so re-exec init to transition to the init domain now

// that the SELinux policy has been loaded.

if (restorecon("/init") == -1) {

PLOG(ERROR) << "restorecon failed";

security_failure();

}

setenv("INIT_SECOND_STAGE", "true", 1);

static constexpr uint32_t kNanosecondsPerMillisecond = 1e6;

uint64_t start_ms = start__since_epoch().count() / kNanosecondsPerMillisecond;

setenv("INIT_STARTED_AT", StringPrintf("%" PRIu64, start_ms).c_str(), 1);

char* path = argv[0];

char* args[] = { path, nullptr };

execv(path, args);

// execv() only returns if an error happened, in which case we

// panic and never fall through this conditional.

PLOG(ERROR) << "execv("" << path << "") failed";

security_failure();

}

// At this point we're in the second stage of init.

InitKernelLogging(argv);

LOG(INFO) << "init second stage started!";

// Set up a session keyring that all processes will have access to. It

// will hold things like FBE encryption keys. No process should override

// its session keyring.

keyctl(KEYCTL_GET_KEYRING_ID, KEY_SPEC_SESSION_KEYRING, 1);

// Indicate that booting is in progress to background fw loaders, etc.

close(open("/dev/.booting", O_WRONLY | O_CREAT | O_CLOEXEC, 0000));

property_init();

// If arguments are passed both on the command line and in DT,

// properties set in DT always have priority over the command-line ones.

process_kernel_dt();

process_kernel_cmdline();

// Propagate the kernel variables to internal variables

// used by init as well as the current required properties.

export_kernel_boot_props();

// Make the time that init started available for bootstat to log.

property_set("", getenv("INIT_STARTED_AT"));

property_set("x", getenv("INIT_SELINUX_TOOK"));

// Set libavb version for Framework-only OTA match in Treble build.

const char* avb_version = getenv("INIT_AVB_VERSION");

if (avb_version) property_set("_version", avb_version);

// Clean up our environment.

unsetenv("INIT_SECOND_STAGE");

unsetenv("INIT_STARTED_AT");

unsetenv("INIT_SELINUX_TOOK");

unsetenv("INIT_AVB_VERSION");

// Now set up SELinux for second stage.

selinux_initialize(false);

selinux_restore_context();

epoll_fd = epoll_create1(EPOLL_CLOEXEC);

if (epoll_fd == -1) {

PLOG(ERROR) << "epoll_create1 failed";

exit(1);

}

signal_handler_init();

property_load_boot_defaults();

export_oem_lock_status();

start_property_service();

set_usb_controller();

const BuiltinFunctionMap function_map;

Action::set_function_map(&function_map);

Parser& parser = Parser::GetInstance();

tionParser("service",std::make_unique());

tionParser("on", std::make_unique());

tionParser("import", std::make_unique());

std::string bootscript = GetProperty("_rc", "");

if (()) {

onfig("/");

_is_system_etc_init_loaded(

onfig("/system/etc/init"));

_is_vendor_etc_init_loaded(

onfig("/vendor/etc/init"));

_is_odm_etc_init_loaded(onfig("/odm/etc/init"));

} else {

onfig(bootscript);

_is_system_etc_init_loaded(true);

_is_vendor_etc_init_loaded(true);

_is_odm_etc_init_loaded(true);

}

// Turning this on and letting the INFO logging be discarded adds 0.2s to

// Nexus 9 boot time, so it's disabled by default.

if (false) ate();

ActionManager& am = ActionManager::GetInstance();

ventTrigger("early-init");

// Queue an action that waits for coldboot done so we know ueventd has set up all of /

uiltinAction(wait_for_coldboot_done_action, "wait_for_coldboot_done");

// ... so that we can start queuing up actions that require stuff from /dev.

uiltinAction(mix_hwrng_into_linux_rng_action, "mix_hwrng_into_linux_rng");

uiltinAction(set_mmap_rnd_bits_action, "set_mmap_rnd_bits");

uiltinAction(set_kptr_restrict_action, "set_kptr_restrict");

uiltinAction(keychord_init_action, "keychord_init");

uiltinAction(console_init_action, "console_init");

// Trigger all the boot actions to get us started.

ventTrigger("init");

// Repeat mix_hwrng_into_linux_rng in case /dev/hw_random or /dev/random

// wasn't ready immediately after wait_for_coldboot_done

uiltinAction(mix_hwrng_into_linux_rng_action, "mix_hwrng_into_linux_rng");

// Don't mount filesystems or start core system services in charger mode.

std::string bootmode = GetProperty("de", "");

if (bootmode == "charger") {

ventTrigger("charger");

} else {

ventTrigger("late-init");

}

// Run all property triggers based on current state of the properties.

uiltinAction(queue_property_triggers_action, "queue_property_triggers");

while (true) {

// By default, sleep until something happens.

int epoll_timeout_ms = -1;

if (!(waiting_for_prop || ServiceManager::GetInstance().IsWaitingForExec())) {

eOneCommand();

}

if (!(waiting_for_prop || ServiceManager::GetInstance().IsWaitingForExec())) {

restart_processes();

// If there's a process that needs restarting, wake up in time for that.

if (process_needs_restart_at != 0) {

epoll_timeout_ms = (process_needs_restart_at - time(nullptr)) * 1000;

if (epoll_timeout_ms < 0) epoll_timeout_ms = 0;

}

// If there's more work to do, wake up again immediately.

if (eCommands()) epoll_timeout_ms = 0;

}

epoll_event ev;

int nr = TEMP_FAILURE_RETRY(epoll_wait(epoll_fd, &ev, 1, epoll_timeout_ms));

if (nr == -1) {

PLOG(ERROR) << "epoll_wait failed";

} else if (nr == 1) {

((void (*)()) )();

}

}

return 0;

}