diff --git a/cmds/dumpstate/DumpstateInternal.cpp b/cmds/dumpstate/DumpstateInternal.cpp
new file mode 100644
index 0000000..2d74377
--- /dev/null
+++ b/cmds/dumpstate/DumpstateInternal.cpp
@@ -0,0 +1,162 @@
+/*
+ * Copyright (C) 2016 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.
+ */
+
+#define LOG_TAG "dumpstate"
+
+#include "DumpstateInternal.h"
+
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/capability.h>
+#include <sys/prctl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <cstdint>
+#include <string>
+#include <vector>
+
+#include <android-base/file.h>
+#include <cutils/log.h>
+#include <private/android_filesystem_config.h>
+
+uint64_t Nanotime() {
+    timespec ts;
+    clock_gettime(CLOCK_MONOTONIC, &ts);
+    return static_cast<uint64_t>(ts.tv_sec * NANOS_PER_SEC + ts.tv_nsec);
+}
+
+// Switches to non-root user and group.
+bool DropRootUser() {
+    if (getgid() == AID_SHELL && getuid() == AID_SHELL) {
+        MYLOGD("drop_root_user(): already running as Shell\n");
+        return true;
+    }
+    /* ensure we will keep capabilities when we drop root */
+    if (prctl(PR_SET_KEEPCAPS, 1) < 0) {
+        MYLOGE("prctl(PR_SET_KEEPCAPS) failed: %s\n", strerror(errno));
+        return false;
+    }
+
+    gid_t groups[] = {AID_LOG,          AID_SDCARD_R, AID_SDCARD_RW, AID_MOUNT,    AID_INET,
+                      AID_NET_BW_STATS, AID_READPROC, AID_WAKELOCK,  AID_BLUETOOTH};
+    if (setgroups(sizeof(groups) / sizeof(groups[0]), groups) != 0) {
+        MYLOGE("Unable to setgroups, aborting: %s\n", strerror(errno));
+        return false;
+    }
+    if (setgid(AID_SHELL) != 0) {
+        MYLOGE("Unable to setgid, aborting: %s\n", strerror(errno));
+        return false;
+    }
+    if (setuid(AID_SHELL) != 0) {
+        MYLOGE("Unable to setuid, aborting: %s\n", strerror(errno));
+        return false;
+    }
+
+    struct __user_cap_header_struct capheader;
+    struct __user_cap_data_struct capdata[2];
+    memset(&capheader, 0, sizeof(capheader));
+    memset(&capdata, 0, sizeof(capdata));
+    capheader.version = _LINUX_CAPABILITY_VERSION_3;
+    capheader.pid = 0;
+
+    capdata[CAP_TO_INDEX(CAP_SYSLOG)].permitted =
+        (CAP_TO_MASK(CAP_SYSLOG) | CAP_TO_MASK(CAP_BLOCK_SUSPEND));
+    capdata[CAP_TO_INDEX(CAP_SYSLOG)].effective =
+        (CAP_TO_MASK(CAP_SYSLOG) | CAP_TO_MASK(CAP_BLOCK_SUSPEND));
+    capdata[0].inheritable = 0;
+    capdata[1].inheritable = 0;
+
+    if (capset(&capheader, &capdata[0]) < 0) {
+        MYLOGE("capset failed: %s\n", strerror(errno));
+        return false;
+    }
+
+    return true;
+}
+
+int DumpFileFromFdToFd(const std::string& title, const std::string& path_string, int fd, int out_fd,
+                       bool dry_run) {
+    const char* path = path_string.c_str();
+    if (!title.empty()) {
+        dprintf(out_fd, "------ %s (%s", title.c_str(), path);
+
+        struct stat st;
+        // Only show the modification time of non-device files.
+        size_t path_len = strlen(path);
+        if ((path_len < 6 || memcmp(path, "/proc/", 6)) &&
+            (path_len < 5 || memcmp(path, "/sys/", 5)) &&
+            (path_len < 3 || memcmp(path, "/d/", 3)) && !fstat(fd, &st)) {
+            char stamp[80];
+            time_t mtime = st.st_mtime;
+            strftime(stamp, sizeof(stamp), "%Y-%m-%d %H:%M:%S", localtime(&mtime));
+            dprintf(out_fd, ": %s", stamp);
+        }
+        dprintf(out_fd, ") ------\n");
+        fsync(out_fd);
+    }
+    if (dry_run) {
+        if (out_fd != STDOUT_FILENO) {
+            // There is no title, but we should still print a dry-run message
+            dprintf(out_fd, "%s: skipped on dry run\n", path);
+        } else if (!title.empty()) {
+            dprintf(out_fd, "\t(skipped on dry run)\n");
+        }
+        fsync(out_fd);
+        return 0;
+    }
+    bool newline = false;
+    fd_set read_set;
+    timeval tm;
+    while (true) {
+        FD_ZERO(&read_set);
+        FD_SET(fd, &read_set);
+        /* Timeout if no data is read for 30 seconds. */
+        tm.tv_sec = 30;
+        tm.tv_usec = 0;
+        uint64_t elapsed = Nanotime();
+        int ret = TEMP_FAILURE_RETRY(select(fd + 1, &read_set, nullptr, nullptr, &tm));
+        if (ret == -1) {
+            dprintf(out_fd, "*** %s: select failed: %s\n", path, strerror(errno));
+            newline = true;
+            break;
+        } else if (ret == 0) {
+            elapsed = Nanotime() - elapsed;
+            dprintf(out_fd, "*** %s: Timed out after %.3fs\n", path, (float)elapsed / NANOS_PER_SEC);
+            newline = true;
+            break;
+        } else {
+            char buffer[65536];
+            ssize_t bytes_read = TEMP_FAILURE_RETRY(read(fd, buffer, sizeof(buffer)));
+            if (bytes_read > 0) {
+                android::base::WriteFully(out_fd, buffer, bytes_read);
+                newline = (buffer[bytes_read - 1] == '\n');
+            } else {
+                if (bytes_read == -1) {
+                    dprintf(out_fd, "*** %s: Failed to read from fd: %s", path, strerror(errno));
+                    newline = true;
+                }
+                break;
+            }
+        }
+    }
+    close(fd);
+
+    if (!newline) dprintf(out_fd, "\n");
+    if (!title.empty()) dprintf(out_fd, "\n");
+    return 0;
+}