fastboot: implement fastbootd in twrp
fastbootd is a userspace daemon that runs in the recovery
ramdisk. It allows writing single partitions to the super
partition via fastboot CLI. When TWRP sees the fastboot option
in the misc partition during startup, it will start with
the fastbootd page and fastbootd running. Otherwise it will
run recovery normally.
Change-Id: Id7b12d29ef21dbd5950dc884dd1cd788f25357f0
diff --git a/install/get_args.cpp b/install/get_args.cpp
new file mode 100755
index 0000000..116602e
--- /dev/null
+++ b/install/get_args.cpp
@@ -0,0 +1,91 @@
+#include "install/get_args.h"
+
+std::string stage;
+bool has_cache = false;
+static constexpr const char* COMMAND_FILE = "/cache/recovery/command";
+
+// command line args come from, in decreasing precedence:
+// - the actual command line
+// - the bootloader control block (one per line, after "recovery")
+// - the contents of COMMAND_FILE (one per line)
+std::vector<std::string> args::get_args(const int *argc, char*** const argv) {
+ CHECK_GT(*argc, 0);
+
+ bootloader_message boot = {};
+ std::string err;
+ if (!read_bootloader_message(&boot, &err)) {
+ LOG(ERROR) << err;
+ // If fails, leave a zeroed bootloader_message.
+ boot = {};
+ }
+ stage = std::string(boot.stage);
+
+ std::string boot_command;
+ if (boot.command[0] != 0) {
+ if (memchr(boot.command, '\0', sizeof(boot.command))) {
+ boot_command = std::string(boot.command);
+ } else {
+ boot_command = std::string(boot.command, sizeof(boot.command));
+ }
+ LOG(INFO) << "Boot command: " << boot_command;
+ printf("boot command: %s\n", boot_command.c_str());
+ }
+
+ if (boot.status[0] != 0) {
+ std::string boot_status = std::string(boot.status, sizeof(boot.status));
+ LOG(INFO) << "Boot status: " << boot_status;
+ }
+
+ std::vector<std::string> args(*argv, *argv + *argc);
+
+ // --- if arguments weren't supplied, look in the bootloader control block
+ if (args.size() == 1) {
+ boot.recovery[sizeof(boot.recovery) - 1] = '\0'; // Ensure termination
+ std::string boot_recovery(boot.recovery);
+ std::vector<std::string> tokens = android::base::Split(boot_recovery, "\n");
+ if (!tokens.empty() && tokens[0] == "recovery") {
+ for (auto it = tokens.begin() + 1; it != tokens.end(); it++) {
+ // Skip empty and '\0'-filled tokens.
+ if (!it->empty() && (*it)[0] != '\0') args.push_back(std::move(*it));
+ }
+ LOG(INFO) << "Got " << args.size() << " arguments from boot message";
+ } else if (boot.recovery[0] != 0) {
+ LOG(ERROR) << "Bad boot message: \"" << boot_recovery << "\"";
+ }
+ }
+
+ // --- if that doesn't work, try the command file (if we have /cache).
+ if (args.size() == 1 && has_cache) {
+ std::string content;
+ if (ensure_path_mounted(COMMAND_FILE) == 0 &&
+ android::base::ReadFileToString(COMMAND_FILE, &content)) {
+ std::vector<std::string> tokens = android::base::Split(content, "\n");
+ // All the arguments in COMMAND_FILE are needed (unlike the BCB message,
+ // COMMAND_FILE doesn't use filename as the first argument).
+ for (auto it = tokens.begin(); it != tokens.end(); it++) {
+ // Skip empty and '\0'-filled tokens.
+ if (!it->empty() && (*it)[0] != '\0') args.push_back(std::move(*it));
+ }
+ LOG(INFO) << "Got " << args.size() << " arguments from " << COMMAND_FILE;
+ }
+ }
+
+ // Write the arguments (excluding the filename in args[0]) back into the
+ // bootloader control block. So the device will always boot into recovery to
+ // finish the pending work, until finish_recovery() is called.
+ std::vector<std::string> options(args.cbegin() + 1, args.cend());
+ if (!update_bootloader_message(options, &err)) {
+ LOG(ERROR) << "Failed to set BCB message: " << err;
+ }
+
+ // Finally, if no arguments were specified, check whether we should boot
+ // into fastboot or rescue mode.
+ if (args.size() == 1 && boot_command == "boot-fastboot") {
+ printf("fastbootd needed\n");
+ args.emplace_back("--fastboot");
+ } else if (args.size() == 1 && boot_command == "boot-rescue") {
+ args.emplace_back("--rescue");
+ }
+
+ return args;
+}