diff --git a/debuggerd/debuggerd.cpp b/debuggerd/debuggerd.cpp
new file mode 100644
index 0000000..a9f59c8
--- /dev/null
+++ b/debuggerd/debuggerd.cpp
@@ -0,0 +1,539 @@
+/* system/debuggerd/debuggerd.c
+**
+** Copyright 2006, 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 <stdio.h>
+#include <errno.h>
+#include <signal.h>
+#include <pthread.h>
+#include <stdarg.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <time.h>
+
+#include <sys/ptrace.h>
+#include <sys/wait.h>
+#include <elf.h>
+#include <sys/stat.h>
+#include <sys/poll.h>
+
+#include <log/logd.h>
+#include <log/logger.h>
+
+#include <cutils/sockets.h>
+#include <cutils/properties.h>
+#include <cutils/debugger.h>
+
+#include <corkscrew/backtrace.h>
+
+#include <linux/input.h>
+
+#include <private/android_filesystem_config.h>
+
+#include "backtrace.h"
+#include "getevent.h"
+#include "tombstone.h"
+#include "utility.h"
+
+typedef struct {
+    debugger_action_t action;
+    pid_t pid, tid;
+    uid_t uid, gid;
+    uintptr_t abort_msg_address;
+} debugger_request_t;
+
+static int
+write_string(const char* file, const char* string)
+{
+    int len;
+    int fd;
+    ssize_t amt;
+    fd = open(file, O_RDWR);
+    len = strlen(string);
+    if (fd < 0)
+        return -errno;
+    amt = write(fd, string, len);
+    close(fd);
+    return amt >= 0 ? 0 : -errno;
+}
+
+static
+void init_debug_led(void)
+{
+    // trout leds
+    write_string("/sys/class/leds/red/brightness", "0");
+    write_string("/sys/class/leds/green/brightness", "0");
+    write_string("/sys/class/leds/blue/brightness", "0");
+    write_string("/sys/class/leds/red/device/blink", "0");
+    // sardine leds
+    write_string("/sys/class/leds/left/cadence", "0,0");
+}
+
+static
+void enable_debug_led(void)
+{
+    // trout leds
+    write_string("/sys/class/leds/red/brightness", "255");
+    // sardine leds
+    write_string("/sys/class/leds/left/cadence", "1,0");
+}
+
+static
+void disable_debug_led(void)
+{
+    // trout leds
+    write_string("/sys/class/leds/red/brightness", "0");
+    // sardine leds
+    write_string("/sys/class/leds/left/cadence", "0,0");
+}
+
+static void wait_for_user_action(pid_t pid) {
+    /* First log a helpful message */
+    LOG(    "********************************************************\n"
+            "* Process %d has been suspended while crashing.  To\n"
+            "* attach gdbserver for a gdb connection on port 5039\n"
+            "* and start gdbclient:\n"
+            "*\n"
+            "*     gdbclient app_process :5039 %d\n"
+            "*\n"
+            "* Wait for gdb to start, then press HOME or VOLUME DOWN key\n"
+            "* to let the process continue crashing.\n"
+            "********************************************************\n",
+            pid, pid);
+
+    /* wait for HOME or VOLUME DOWN key */
+    if (init_getevent() == 0) {
+        int ms = 1200 / 10;
+        int dit = 1;
+        int dah = 3*dit;
+        int _       = -dit;
+        int ___     = 3*_;
+        int _______ = 7*_;
+        const int codes[] = {
+           dit,_,dit,_,dit,___,dah,_,dah,_,dah,___,dit,_,dit,_,dit,_______
+        };
+        size_t s = 0;
+        struct input_event e;
+        bool done = false;
+        init_debug_led();
+        enable_debug_led();
+        do {
+            int timeout = abs(codes[s]) * ms;
+            int res = get_event(&e, timeout);
+            if (res == 0) {
+                if (e.type == EV_KEY
+                        && (e.code == KEY_HOME || e.code == KEY_VOLUMEDOWN)
+                        && e.value == 0) {
+                    done = true;
+                }
+            } else if (res == 1) {
+                if (++s >= sizeof(codes)/sizeof(*codes))
+                    s = 0;
+                if (codes[s] > 0) {
+                    enable_debug_led();
+                } else {
+                    disable_debug_led();
+                }
+            }
+        } while (!done);
+        uninit_getevent();
+    }
+
+    /* don't forget to turn debug led off */
+    disable_debug_led();
+    LOG("debuggerd resuming process %d", pid);
+}
+
+static int get_process_info(pid_t tid, pid_t* out_pid, uid_t* out_uid, uid_t* out_gid) {
+    char path[64];
+    snprintf(path, sizeof(path), "/proc/%d/status", tid);
+
+    FILE* fp = fopen(path, "r");
+    if (!fp) {
+        return -1;
+    }
+
+    int fields = 0;
+    char line[1024];
+    while (fgets(line, sizeof(line), fp)) {
+        size_t len = strlen(line);
+        if (len > 6 && !memcmp(line, "Tgid:\t", 6)) {
+            *out_pid = atoi(line + 6);
+            fields |= 1;
+        } else if (len > 5 && !memcmp(line, "Uid:\t", 5)) {
+            *out_uid = atoi(line + 5);
+            fields |= 2;
+        } else if (len > 5 && !memcmp(line, "Gid:\t", 5)) {
+            *out_gid = atoi(line + 5);
+            fields |= 4;
+        }
+    }
+    fclose(fp);
+    return fields == 7 ? 0 : -1;
+}
+
+static int read_request(int fd, debugger_request_t* out_request) {
+    struct ucred cr;
+    int len = sizeof(cr);
+    int status = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &cr, &len);
+    if (status != 0) {
+        LOG("cannot get credentials\n");
+        return -1;
+    }
+
+    XLOG("reading tid\n");
+    fcntl(fd, F_SETFL, O_NONBLOCK);
+
+    struct pollfd pollfds[1];
+    pollfds[0].fd = fd;
+    pollfds[0].events = POLLIN;
+    pollfds[0].revents = 0;
+    status = TEMP_FAILURE_RETRY(poll(pollfds, 1, 3000));
+    if (status != 1) {
+        LOG("timed out reading tid (from pid=%d uid=%d)\n", cr.pid, cr.uid);
+        return -1;
+    }
+
+    debugger_msg_t msg;
+    memset(&msg, 0, sizeof(msg));
+    status = TEMP_FAILURE_RETRY(read(fd, &msg, sizeof(msg)));
+    if (status < 0) {
+        LOG("read failure? %s (pid=%d uid=%d)\n",
+            strerror(errno), cr.pid, cr.uid);
+        return -1;
+    }
+    if (status == sizeof(debugger_msg_t)) {
+        XLOG("crash request of size %d abort_msg_address=%#08x\n", status, msg.abort_msg_address);
+    } else {
+        LOG("invalid crash request of size %d (from pid=%d uid=%d)\n",
+            status, cr.pid, cr.uid);
+        return -1;
+    }
+
+    out_request->action = msg.action;
+    out_request->tid = msg.tid;
+    out_request->pid = cr.pid;
+    out_request->uid = cr.uid;
+    out_request->gid = cr.gid;
+    out_request->abort_msg_address = msg.abort_msg_address;
+
+    if (msg.action == DEBUGGER_ACTION_CRASH) {
+        /* Ensure that the tid reported by the crashing process is valid. */
+        char buf[64];
+        struct stat s;
+        snprintf(buf, sizeof buf, "/proc/%d/task/%d", out_request->pid, out_request->tid);
+        if(stat(buf, &s)) {
+            LOG("tid %d does not exist in pid %d. ignoring debug request\n",
+                    out_request->tid, out_request->pid);
+            return -1;
+        }
+    } else if (cr.uid == 0
+            || (cr.uid == AID_SYSTEM && msg.action == DEBUGGER_ACTION_DUMP_BACKTRACE)) {
+        /* Only root or system can ask us to attach to any process and dump it explicitly.
+         * However, system is only allowed to collect backtraces but cannot dump tombstones. */
+        status = get_process_info(out_request->tid, &out_request->pid,
+                &out_request->uid, &out_request->gid);
+        if (status < 0) {
+            LOG("tid %d does not exist. ignoring explicit dump request\n",
+                    out_request->tid);
+            return -1;
+        }
+    } else {
+        /* No one else is allowed to dump arbitrary processes. */
+        return -1;
+    }
+    return 0;
+}
+
+static bool should_attach_gdb(debugger_request_t* request) {
+    if (request->action == DEBUGGER_ACTION_CRASH) {
+        char value[PROPERTY_VALUE_MAX];
+        property_get("debug.db.uid", value, "-1");
+        int debug_uid = atoi(value);
+        return debug_uid >= 0 && request->uid <= (uid_t)debug_uid;
+    }
+    return false;
+}
+
+static void handle_request(int fd) {
+    XLOG("handle_request(%d)\n", fd);
+
+    debugger_request_t request;
+    memset(&request, 0, sizeof(request));
+    int status = read_request(fd, &request);
+    if (!status) {
+        XLOG("BOOM: pid=%d uid=%d gid=%d tid=%d\n",
+            request.pid, request.uid, request.gid, request.tid);
+
+        /* At this point, the thread that made the request is blocked in
+         * a read() call.  If the thread has crashed, then this gives us
+         * time to PTRACE_ATTACH to it before it has a chance to really fault.
+         *
+         * The PTRACE_ATTACH sends a SIGSTOP to the target process, but it
+         * won't necessarily have stopped by the time ptrace() returns.  (We
+         * currently assume it does.)  We write to the file descriptor to
+         * ensure that it can run as soon as we call PTRACE_CONT below.
+         * See details in bionic/libc/linker/debugger.c, in function
+         * debugger_signal_handler().
+         */
+        if (ptrace(PTRACE_ATTACH, request.tid, 0, 0)) {
+            LOG("ptrace attach failed: %s\n", strerror(errno));
+        } else {
+            bool detach_failed = false;
+            bool attach_gdb = should_attach_gdb(&request);
+            if (TEMP_FAILURE_RETRY(write(fd, "\0", 1)) != 1) {
+                LOG("failed responding to client: %s\n", strerror(errno));
+            } else {
+                char* tombstone_path = NULL;
+
+                if (request.action == DEBUGGER_ACTION_CRASH) {
+                    close(fd);
+                    fd = -1;
+                }
+
+                int total_sleep_time_usec = 0;
+                for (;;) {
+                    int signal = wait_for_signal(request.tid, &total_sleep_time_usec);
+                    if (signal < 0) {
+                        break;
+                    }
+
+                    switch (signal) {
+                    case SIGSTOP:
+                        if (request.action == DEBUGGER_ACTION_DUMP_TOMBSTONE) {
+                            XLOG("stopped -- dumping to tombstone\n");
+                            tombstone_path = engrave_tombstone(request.pid, request.tid,
+                                    signal, request.abort_msg_address, true, true, &detach_failed,
+                                    &total_sleep_time_usec);
+                        } else if (request.action == DEBUGGER_ACTION_DUMP_BACKTRACE) {
+                            XLOG("stopped -- dumping to fd\n");
+                            dump_backtrace(fd, -1,
+                                    request.pid, request.tid, &detach_failed,
+                                    &total_sleep_time_usec);
+                        } else {
+                            XLOG("stopped -- continuing\n");
+                            status = ptrace(PTRACE_CONT, request.tid, 0, 0);
+                            if (status) {
+                                LOG("ptrace continue failed: %s\n", strerror(errno));
+                            }
+                            continue; /* loop again */
+                        }
+                        break;
+
+                    case SIGILL:
+                    case SIGABRT:
+                    case SIGBUS:
+                    case SIGFPE:
+                    case SIGSEGV:
+                    case SIGPIPE:
+#ifdef SIGSTKFLT
+                    case SIGSTKFLT:
+#endif
+                        {
+                        XLOG("stopped -- fatal signal\n");
+                        /*
+                         * Send a SIGSTOP to the process to make all of
+                         * the non-signaled threads stop moving.  Without
+                         * this we get a lot of "ptrace detach failed:
+                         * No such process".
+                         */
+                        kill(request.pid, SIGSTOP);
+                        /* don't dump sibling threads when attaching to GDB because it
+                         * makes the process less reliable, apparently... */
+                        tombstone_path = engrave_tombstone(request.pid, request.tid,
+                                signal, request.abort_msg_address, !attach_gdb, false,
+                                &detach_failed, &total_sleep_time_usec);
+                        break;
+                    }
+
+                    default:
+                        XLOG("stopped -- unexpected signal\n");
+                        LOG("process stopped due to unexpected signal %d\n", signal);
+                        break;
+                    }
+                    break;
+                }
+
+                if (request.action == DEBUGGER_ACTION_DUMP_TOMBSTONE) {
+                    if (tombstone_path) {
+                        write(fd, tombstone_path, strlen(tombstone_path));
+                    }
+                    close(fd);
+                    fd = -1;
+                }
+                free(tombstone_path);
+            }
+
+            XLOG("detaching\n");
+            if (attach_gdb) {
+                /* stop the process so we can debug */
+                kill(request.pid, SIGSTOP);
+
+                /* detach so we can attach gdbserver */
+                if (ptrace(PTRACE_DETACH, request.tid, 0, 0)) {
+                    LOG("ptrace detach from %d failed: %s\n", request.tid, strerror(errno));
+                    detach_failed = true;
+                }
+
+                /*
+                 * if debug.db.uid is set, its value indicates if we should wait
+                 * for user action for the crashing process.
+                 * in this case, we log a message and turn the debug LED on
+                 * waiting for a gdb connection (for instance)
+                 */
+                wait_for_user_action(request.pid);
+            } else {
+                /* just detach */
+                if (ptrace(PTRACE_DETACH, request.tid, 0, 0)) {
+                    LOG("ptrace detach from %d failed: %s\n", request.tid, strerror(errno));
+                    detach_failed = true;
+                }
+            }
+
+            /* resume stopped process (so it can crash in peace). */
+            kill(request.pid, SIGCONT);
+
+            /* If we didn't successfully detach, we're still the parent, and the
+             * actual parent won't receive a death notification via wait(2).  At this point
+             * there's not much we can do about that. */
+            if (detach_failed) {
+                LOG("debuggerd committing suicide to free the zombie!\n");
+                kill(getpid(), SIGKILL);
+            }
+        }
+
+    }
+    if (fd >= 0) {
+        close(fd);
+    }
+}
+
+static int do_server() {
+    int s;
+    struct sigaction act;
+    int logsocket = -1;
+
+    /*
+     * debuggerd crashes can't be reported to debuggerd.  Reset all of the
+     * crash handlers.
+     */
+    signal(SIGILL, SIG_DFL);
+    signal(SIGABRT, SIG_DFL);
+    signal(SIGBUS, SIG_DFL);
+    signal(SIGFPE, SIG_DFL);
+    signal(SIGSEGV, SIG_DFL);
+#ifdef SIGSTKFLT
+    signal(SIGSTKFLT, SIG_DFL);
+#endif
+
+    // Ignore failed writes to closed sockets
+    signal(SIGPIPE, SIG_IGN);
+
+    logsocket = socket_local_client("logd",
+            ANDROID_SOCKET_NAMESPACE_ABSTRACT, SOCK_DGRAM);
+    if(logsocket < 0) {
+        logsocket = -1;
+    } else {
+        fcntl(logsocket, F_SETFD, FD_CLOEXEC);
+    }
+
+    act.sa_handler = SIG_DFL;
+    sigemptyset(&act.sa_mask);
+    sigaddset(&act.sa_mask,SIGCHLD);
+    act.sa_flags = SA_NOCLDWAIT;
+    sigaction(SIGCHLD, &act, 0);
+
+    s = socket_local_server(DEBUGGER_SOCKET_NAME,
+            ANDROID_SOCKET_NAMESPACE_ABSTRACT, SOCK_STREAM);
+    if(s < 0) return 1;
+    fcntl(s, F_SETFD, FD_CLOEXEC);
+
+    LOG("debuggerd: " __DATE__ " " __TIME__ "\n");
+
+    for(;;) {
+        struct sockaddr addr;
+        socklen_t alen;
+        int fd;
+
+        alen = sizeof(addr);
+        XLOG("waiting for connection\n");
+        fd = accept(s, &addr, &alen);
+        if(fd < 0) {
+            XLOG("accept failed: %s\n", strerror(errno));
+            continue;
+        }
+
+        fcntl(fd, F_SETFD, FD_CLOEXEC);
+
+        handle_request(fd);
+    }
+    return 0;
+}
+
+static int do_explicit_dump(pid_t tid, bool dump_backtrace) {
+    fprintf(stdout, "Sending request to dump task %d.\n", tid);
+
+    if (dump_backtrace) {
+        fflush(stdout);
+        if (dump_backtrace_to_file(tid, fileno(stdout)) < 0) {
+            fputs("Error dumping backtrace.\n", stderr);
+            return 1;
+        }
+    } else {
+        char tombstone_path[PATH_MAX];
+        if (dump_tombstone(tid, tombstone_path, sizeof(tombstone_path)) < 0) {
+            fputs("Error dumping tombstone.\n", stderr);
+            return 1;
+        }
+        fprintf(stderr, "Tombstone written to: %s\n", tombstone_path);
+    }
+    return 0;
+}
+
+static void usage() {
+    fputs("Usage: -b [<tid>]\n"
+            "  -b dump backtrace to console, otherwise dump full tombstone file\n"
+            "\n"
+            "If tid specified, sends a request to debuggerd to dump that task.\n"
+            "Otherwise, starts the debuggerd server.\n", stderr);
+}
+
+int main(int argc, char** argv) {
+    if (argc == 1) {
+        return do_server();
+    }
+
+    bool dump_backtrace = false;
+    bool have_tid = false;
+    pid_t tid = 0;
+    for (int i = 1; i < argc; i++) {
+        if (!strcmp(argv[i], "-b")) {
+            dump_backtrace = true;
+        } else if (!have_tid) {
+            tid = atoi(argv[i]);
+            have_tid = true;
+        } else {
+            usage();
+            return 1;
+        }
+    }
+    if (!have_tid) {
+        usage();
+        return 1;
+    }
+    return do_explicit_dump(tid, dump_backtrace);
+}