diff --git a/minadbd/adb.c b/minadbd/adb.c
index 948f4b7..7291b4b 100644
--- a/minadbd/adb.c
+++ b/minadbd/adb.c
@@ -387,7 +387,7 @@
     init_transport_registration();
 
     // The minimal version of adbd only uses USB.
-    if (access("/dev/android_adb", F_OK) == 0) {
+    if (access(USB_ADB_PATH, F_OK) == 0 || access(USB_FFS_ADB_EP0, F_OK) == 0) {
         // listen on USB
         usb_init();
     }
diff --git a/minadbd/adb.h b/minadbd/adb.h
index 688a6f2..d389165 100644
--- a/minadbd/adb.h
+++ b/minadbd/adb.h
@@ -406,6 +406,17 @@
 
 #define CHUNK_SIZE (64*1024)
 
+#if !ADB_HOST
+#define USB_ADB_PATH     "/dev/android_adb"
+
+#define USB_FFS_ADB_PATH  "/dev/usb-ffs/adb/"
+#define USB_FFS_ADB_EP(x) USB_FFS_ADB_PATH#x
+
+#define USB_FFS_ADB_EP0   USB_FFS_ADB_EP(ep0)
+#define USB_FFS_ADB_OUT   USB_FFS_ADB_EP(ep1)
+#define USB_FFS_ADB_IN    USB_FFS_ADB_EP(ep2)
+#endif
+
 int sendfailmsg(int fd, const char *reason);
 int handle_host_request(char *service, transport_type ttype, char* serial, int reply_fd, asocket *s);
 
diff --git a/minadbd/usb_linux_client.c b/minadbd/usb_linux_client.c
index 635fa4b..c135d63 100644
--- a/minadbd/usb_linux_client.c
+++ b/minadbd/usb_linux_client.c
@@ -19,6 +19,8 @@
 #include <unistd.h>
 #include <string.h>
 
+#include <linux/usb/ch9.h>
+#include <linux/usb/functionfs.h>
 #include <sys/ioctl.h>
 #include <sys/types.h>
 #include <dirent.h>
@@ -29,12 +31,114 @@
 #define   TRACE_TAG  TRACE_USB
 #include "adb.h"
 
+#define MAX_PACKET_SIZE_FS	64
+#define MAX_PACKET_SIZE_HS	512
+
+#define cpu_to_le16(x)  htole16(x)
+#define cpu_to_le32(x)  htole32(x)
 
 struct usb_handle
 {
     int fd;
     adb_cond_t notify;
     adb_mutex_t lock;
+
+    int (*write)(usb_handle *h, const void *data, int len);
+    int (*read)(usb_handle *h, void *data, int len);
+    void (*kick)(usb_handle *h);
+
+    int control;
+    int bulk_out; /* "out" from the host's perspective => source for adbd */
+    int bulk_in;  /* "in" from the host's perspective => sink for adbd */
+};
+
+static const struct {
+    struct usb_functionfs_descs_head header;
+    struct {
+        struct usb_interface_descriptor intf;
+        struct usb_endpoint_descriptor_no_audio source;
+        struct usb_endpoint_descriptor_no_audio sink;
+    } __attribute__((packed)) fs_descs, hs_descs;
+} __attribute__((packed)) descriptors = {
+    .header = {
+        .magic = cpu_to_le32(FUNCTIONFS_DESCRIPTORS_MAGIC),
+        .length = cpu_to_le32(sizeof(descriptors)),
+        .fs_count = 3,
+        .hs_count = 3,
+    },
+    .fs_descs = {
+        .intf = {
+            .bLength = sizeof(descriptors.fs_descs.intf),
+            .bDescriptorType = USB_DT_INTERFACE,
+            .bInterfaceNumber = 0,
+            .bNumEndpoints = 2,
+            .bInterfaceClass = ADB_CLASS,
+            .bInterfaceSubClass = ADB_SUBCLASS,
+            .bInterfaceProtocol = ADB_PROTOCOL,
+            .iInterface = 1, /* first string from the provided table */
+        },
+        .source = {
+            .bLength = sizeof(descriptors.fs_descs.source),
+            .bDescriptorType = USB_DT_ENDPOINT,
+            .bEndpointAddress = 1 | USB_DIR_OUT,
+            .bmAttributes = USB_ENDPOINT_XFER_BULK,
+            .wMaxPacketSize = MAX_PACKET_SIZE_FS,
+        },
+        .sink = {
+            .bLength = sizeof(descriptors.fs_descs.sink),
+            .bDescriptorType = USB_DT_ENDPOINT,
+            .bEndpointAddress = 2 | USB_DIR_IN,
+            .bmAttributes = USB_ENDPOINT_XFER_BULK,
+            .wMaxPacketSize = MAX_PACKET_SIZE_FS,
+        },
+    },
+    .hs_descs = {
+        .intf = {
+            .bLength = sizeof(descriptors.hs_descs.intf),
+            .bDescriptorType = USB_DT_INTERFACE,
+            .bInterfaceNumber = 0,
+            .bNumEndpoints = 2,
+            .bInterfaceClass = ADB_CLASS,
+            .bInterfaceSubClass = ADB_SUBCLASS,
+            .bInterfaceProtocol = ADB_PROTOCOL,
+            .iInterface = 1, /* first string from the provided table */
+        },
+        .source = {
+            .bLength = sizeof(descriptors.hs_descs.source),
+            .bDescriptorType = USB_DT_ENDPOINT,
+            .bEndpointAddress = 1 | USB_DIR_OUT,
+            .bmAttributes = USB_ENDPOINT_XFER_BULK,
+            .wMaxPacketSize = MAX_PACKET_SIZE_HS,
+        },
+        .sink = {
+            .bLength = sizeof(descriptors.hs_descs.sink),
+            .bDescriptorType = USB_DT_ENDPOINT,
+            .bEndpointAddress = 2 | USB_DIR_IN,
+            .bmAttributes = USB_ENDPOINT_XFER_BULK,
+            .wMaxPacketSize = MAX_PACKET_SIZE_HS,
+        },
+    },
+};
+
+#define STR_INTERFACE_ "ADB Interface"
+
+static const struct {
+    struct usb_functionfs_strings_head header;
+    struct {
+        __le16 code;
+        const char str1[sizeof(STR_INTERFACE_)];
+    } __attribute__((packed)) lang0;
+} __attribute__((packed)) strings = {
+    .header = {
+        .magic = cpu_to_le32(FUNCTIONFS_STRINGS_MAGIC),
+        .length = cpu_to_le32(sizeof(strings)),
+        .str_count = cpu_to_le32(1),
+        .lang_count = cpu_to_le32(1),
+    },
+    .lang0 = {
+        cpu_to_le16(0x0409), /* en-us */
+        STR_INTERFACE_,
+    },
 };
 
 void usb_cleanup()
@@ -42,7 +146,7 @@
     // nothing to do here
 }
 
-static void *usb_open_thread(void *x)
+static void *usb_adb_open_thread(void *x)
 {
     struct usb_handle *usb = (struct usb_handle *)x;
     int fd;
@@ -61,6 +165,7 @@
             if (fd < 0) {
                 // to support older kernels
                 fd = unix_open("/dev/android", O_RDWR);
+                fprintf(stderr, "usb_adb_open_thread: %d\n", fd );
             }
             if (fd < 0) {
                 adb_sleep_ms(1000);
@@ -79,7 +184,7 @@
     return 0;
 }
 
-int usb_write(usb_handle *h, const void *data, int len)
+static int usb_adb_write(usb_handle *h, const void *data, int len)
 {
     int n;
 
@@ -94,7 +199,7 @@
     return 0;
 }
 
-int usb_read(usb_handle *h, void *data, int len)
+static int usb_adb_read(usb_handle *h, void *data, int len)
 {
     int n;
 
@@ -109,23 +214,42 @@
     return 0;
 }
 
-void usb_init()
+static void usb_adb_kick(usb_handle *h)
+{
+    D("usb_kick\n");
+    adb_mutex_lock(&h->lock);
+    adb_close(h->fd);
+    h->fd = -1;
+
+    // notify usb_adb_open_thread that we are disconnected
+    adb_cond_signal(&h->notify);
+    adb_mutex_unlock(&h->lock);
+}
+
+static void usb_adb_init()
 {
     usb_handle *h;
     adb_thread_t tid;
     int fd;
 
     h = calloc(1, sizeof(usb_handle));
+
+    h->write = usb_adb_write;
+    h->read = usb_adb_read;
+    h->kick = usb_adb_kick;
     h->fd = -1;
+
     adb_cond_init(&h->notify, 0);
     adb_mutex_init(&h->lock, 0);
 
+    fprintf(stderr, "Starting to open usb_init()\n");
     // Open the file /dev/android_adb_enable to trigger 
     // the enabling of the adb USB function in the kernel.
     // We never touch this file again - just leave it open
     // indefinitely so the kernel will know when we are running
     // and when we are not.
     fd = unix_open("/dev/android_adb_enable", O_RDWR);
+    fprintf(stderr, "unix_open to open usb_init(): %d\n", fd);
     if (fd < 0) {
        D("failed to open /dev/android_adb_enable\n");
     } else {
@@ -133,25 +257,237 @@
     }
 
     D("[ usb_init - starting thread ]\n");
-    if(adb_thread_create(&tid, usb_open_thread, h)){
+    if(adb_thread_create(&tid, usb_adb_open_thread, h)){
         fatal_errno("cannot create usb thread");
+        fprintf(stderr, "cannot create the usb thread()\n");
     }
 }
 
-void usb_kick(usb_handle *h)
-{
-    D("usb_kick\n");
-    adb_mutex_lock(&h->lock);
-    adb_close(h->fd);
-    h->fd = -1;
 
-    // notify usb_open_thread that we are disconnected
+static void init_functionfs(struct usb_handle *h)
+{
+    ssize_t ret;
+
+    D("OPENING %s\n", USB_FFS_ADB_EP0);
+    h->control = adb_open(USB_FFS_ADB_EP0, O_RDWR);
+    if (h->control < 0) {
+        D("[ %s: cannot open control endpoint: errno=%d]\n", USB_FFS_ADB_EP0, errno);
+        goto err;
+    }
+
+    ret = adb_write(h->control, &descriptors, sizeof(descriptors));
+    if (ret < 0) {
+        D("[ %s: write descriptors failed: errno=%d ]\n", USB_FFS_ADB_EP0, errno);
+        goto err;
+    }
+
+    ret = adb_write(h->control, &strings, sizeof(strings));
+    if (ret < 0) {
+        D("[ %s: writing strings failed: errno=%d]\n", USB_FFS_ADB_EP0, errno);
+        goto err;
+    }
+
+    h->bulk_out = adb_open(USB_FFS_ADB_OUT, O_RDWR);
+    if (h->bulk_out < 0) {
+        D("[ %s: cannot open bulk-out ep: errno=%d ]\n", USB_FFS_ADB_OUT, errno);
+        goto err;
+    }
+
+    h->bulk_in = adb_open(USB_FFS_ADB_IN, O_RDWR);
+    if (h->bulk_in < 0) {
+        D("[ %s: cannot open bulk-in ep: errno=%d ]\n", USB_FFS_ADB_IN, errno);
+        goto err;
+    }
+
+    return;
+
+err:
+    if (h->bulk_in > 0) {
+        adb_close(h->bulk_in);
+        h->bulk_in = -1;
+    }
+    if (h->bulk_out > 0) {
+        adb_close(h->bulk_out);
+        h->bulk_out = -1;
+    }
+    if (h->control > 0) {
+        adb_close(h->control);
+        h->control = -1;
+    }
+    return;
+}
+
+static void *usb_ffs_open_thread(void *x)
+{
+    struct usb_handle *usb = (struct usb_handle *)x;
+
+    while (1) {
+        // wait until the USB device needs opening
+        adb_mutex_lock(&usb->lock);
+        while (usb->control != -1)
+            adb_cond_wait(&usb->notify, &usb->lock);
+        adb_mutex_unlock(&usb->lock);
+
+        while (1) {
+            init_functionfs(usb);
+
+            if (usb->control >= 0)
+                break;
+
+            adb_sleep_ms(1000);
+        }
+
+        D("[ usb_thread - registering device ]\n");
+        register_usb_transport(usb, 0, 1);
+    }
+
+    // never gets here
+    return 0;
+}
+
+static int bulk_write(int bulk_in, const char *buf, size_t length)
+{
+    size_t count = 0;
+    int ret;
+
+    do {
+        ret = adb_write(bulk_in, buf + count, length - count);
+        if (ret < 0) {
+            if (errno != EINTR)
+                return ret;
+        } else {
+            count += ret;
+        }
+    } while (count < length);
+
+    D("[ bulk_write done fd=%d ]\n", bulk_in);
+    return count;
+}
+
+static int usb_ffs_write(usb_handle *h, const void *data, int len)
+{
+    int n;
+
+    D("about to write (fd=%d, len=%d)\n", h->bulk_in, len);
+    n = bulk_write(h->bulk_in, data, len);
+    if (n != len) {
+        D("ERROR: fd = %d, n = %d, errno = %d (%s)\n",
+            h->bulk_in, n, errno, strerror(errno));
+        return -1;
+    }
+    D("[ done fd=%d ]\n", h->bulk_in);
+    return 0;
+}
+
+static int bulk_read(int bulk_out, char *buf, size_t length)
+{
+    size_t count = 0;
+    int ret;
+
+    do {
+        ret = adb_read(bulk_out, buf + count, length - count);
+        if (ret < 0) {
+            if (errno != EINTR) {
+                D("[ bulk_read failed fd=%d length=%d count=%d ]\n",
+                                           bulk_out, length, count);
+                return ret;
+            }
+        } else {
+            count += ret;
+        }
+    } while (count < length);
+
+    return count;
+}
+
+static int usb_ffs_read(usb_handle *h, void *data, int len)
+{
+    int n;
+
+    D("about to read (fd=%d, len=%d)\n", h->bulk_out, len);
+    n = bulk_read(h->bulk_out, data, len);
+    if (n != len) {
+        D("ERROR: fd = %d, n = %d, errno = %d (%s)\n",
+            h->bulk_out, n, errno, strerror(errno));
+        return -1;
+    }
+    D("[ done fd=%d ]\n", h->bulk_out);
+    return 0;
+}
+
+static void usb_ffs_kick(usb_handle *h)
+{
+    int err;
+
+    err = ioctl(h->bulk_in, FUNCTIONFS_CLEAR_HALT);
+    if (err < 0)
+        D("[ kick: source (fd=%d) clear halt failed (%d) ]", h->bulk_in, errno);
+
+    err = ioctl(h->bulk_out, FUNCTIONFS_CLEAR_HALT);
+    if (err < 0)
+        D("[ kick: sink (fd=%d) clear halt failed (%d) ]", h->bulk_out, errno);
+
+    adb_mutex_lock(&h->lock);
+    adb_close(h->control);
+    adb_close(h->bulk_out);
+    adb_close(h->bulk_in);
+    h->control = h->bulk_out = h->bulk_in = -1;
+
+    // notify usb_ffs_open_thread that we are disconnected
     adb_cond_signal(&h->notify);
     adb_mutex_unlock(&h->lock);
 }
 
+static void usb_ffs_init()
+{
+    usb_handle *h;
+    adb_thread_t tid;
+
+    D("[ usb_init - using FunctionFS ]\n");
+
+    h = calloc(1, sizeof(usb_handle));
+
+    h->write = usb_ffs_write;
+    h->read = usb_ffs_read;
+    h->kick = usb_ffs_kick;
+
+    h->control  = -1;
+    h->bulk_out = -1;
+    h->bulk_out = -1;
+
+    adb_cond_init(&h->notify, 0);
+    adb_mutex_init(&h->lock, 0);
+
+    D("[ usb_init - starting thread ]\n");
+    if (adb_thread_create(&tid, usb_ffs_open_thread, h)){
+        fatal_errno("[ cannot create usb thread ]\n");
+    }
+}
+
+void usb_init()
+{
+    if (access(USB_FFS_ADB_EP0, F_OK) == 0)
+        usb_ffs_init();
+    else
+        usb_adb_init();
+}
+
+int usb_write(usb_handle *h, const void *data, int len)
+{
+    return h->write(h, data, len);
+}
+
+int usb_read(usb_handle *h, void *data, int len)
+{
+    return h->read(h, data, len);
+}
 int usb_close(usb_handle *h)
 {
     // nothing to do here
     return 0;
 }
+
+void usb_kick(usb_handle *h)
+{
+    h->kick(h);
+}