usb/gadget: add the fastboot gadget
authorSebastian Siewior <bigeasy@linutronix.de>
Mon, 5 May 2014 20:08:10 +0000 (15:08 -0500)
committerLukasz Majewski <l.majewski@samsung.com>
Thu, 8 May 2014 08:38:30 +0000 (10:38 +0200)
This patch contains an implementation of the fastboot protocol on the
device side and documentation. This is based on USB download gadget
infrastructure. The fastboot function implements the getvar, reboot,
download and reboot commands. What is missing is the flash handling i.e.
writting the image to media.

v3 (Rob Herring):
This is based on http://patchwork.ozlabs.org/patch/126798/ with the
following changes:
- Rebase to current mainline and updates for current gadget API
- Use SPDX identifiers for licenses
- Traced the history and added missing copyright to cmd_fastboot.c
- Use load_addr/load_size for transfer buffer
- Allow vendor strings to be optional
- Set vendor/product ID from config defines
- Allow Ctrl-C to exit fastboot mode
v4:
- Major re-write to use the USB download gadget. Consolidated function
code to a single file.
- Moved globals into single struct.
- Use puts and putc as appropriate.
- Added CONFIG_USB_FASTBOOT_BUF_ADDR and CONFIG_USB_FASTBOOT_BUF_SIZE to
set the fastboot transfer buffer.
v5:
- Add CONFIG option documentation to README
- Rebase using new downloader registration

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Rob Herring <robh@kernel.org>
README
common/Makefile
common/cmd_fastboot.c [new file with mode: 0644]
doc/README.android-fastboot [new file with mode: 0644]
doc/README.android-fastboot-protocol [new file with mode: 0644]
drivers/usb/gadget/Makefile
drivers/usb/gadget/f_fastboot.c [new file with mode: 0644]

diff --git a/README b/README
index b973344184f23210a9ff40b5d311a022df4eec2c..8114f79e660d3674813b59dc868261b05cc78364 100644 (file)
--- a/README
+++ b/README
@@ -1558,6 +1558,28 @@ The following options need to be configured:
                entering dfuMANIFEST state. Host waits this timeout, before
                sending again an USB request to the device.
 
+- USB Device Android Fastboot support:
+               CONFIG_CMD_FASTBOOT
+               This enables the command "fastboot" which enables the Android
+               fastboot mode for the platform's USB device. Fastboot is a USB
+               protocol for downloading images, flashing and device control
+               used on Android devices.
+               See doc/README.android-fastboot for more information.
+
+               CONFIG_ANDROID_BOOT_IMAGE
+               This enables support for booting images which use the Android
+               image format header.
+
+               CONFIG_USB_FASTBOOT_BUF_ADDR
+               The fastboot protocol requires a large memory buffer for
+               downloads. Define this to the starting RAM address to use for
+               downloaded images.
+
+               CONFIG_USB_FASTBOOT_BUF_SIZE
+               The fastboot protocol requires a large memory buffer for
+               downloads. This buffer should be as large as possible for a
+               platform. Define this to the size available RAM for fastboot.
+
 - Journaling Flash filesystem support:
                CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
                CONFIG_JFFS2_NAND_DEV
index bfcb4664b7ba7f122670228cf990e4e01a17234a..219cb51b2d70c956b11a6666687dfe019d948490 100644 (file)
@@ -168,6 +168,8 @@ obj-y += cmd_usb.o
 obj-y += usb.o usb_hub.o
 obj-$(CONFIG_USB_STORAGE) += usb_storage.o
 endif
+obj-$(CONFIG_CMD_FASTBOOT) += cmd_fastboot.o
+
 obj-$(CONFIG_CMD_USB_MASS_STORAGE) += cmd_usb_mass_storage.o
 obj-$(CONFIG_CMD_THOR_DOWNLOAD) += cmd_thordown.o
 obj-$(CONFIG_CMD_XIMG) += cmd_ximg.o
diff --git a/common/cmd_fastboot.c b/common/cmd_fastboot.c
new file mode 100644 (file)
index 0000000..83fa7bd
--- /dev/null
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2008 - 2009 Windriver, <www.windriver.com>
+ * Author: Tom Rix <Tom.Rix@windriver.com>
+ *
+ * (C) Copyright 2014 Linaro, Ltd.
+ * Rob Herring <robh@kernel.org>
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+#include <common.h>
+#include <command.h>
+#include <g_dnl.h>
+
+static int do_fastboot(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
+{
+       int ret;
+
+       ret = g_dnl_register("usb_dnl_fastboot");
+       if (ret)
+               return ret;
+
+       while (1) {
+               if (ctrlc())
+                       break;
+               usb_gadget_handle_interrupts();
+       }
+
+       g_dnl_unregister();
+       return CMD_RET_SUCCESS;
+}
+
+U_BOOT_CMD(
+       fastboot,       1,      1,      do_fastboot,
+       "fastboot - enter USB Fastboot protocol",
+       ""
+);
diff --git a/doc/README.android-fastboot b/doc/README.android-fastboot
new file mode 100644 (file)
index 0000000..f1d128c
--- /dev/null
@@ -0,0 +1,91 @@
+Android Fastboot
+~~~~~~~~~~~~~~~~
+
+Overview
+========
+The protocol that is used over USB is described in
+README.android-fastboot-protocol in same directory.
+
+The current implementation does not yet support the flash and erase
+commands.
+
+Client installation
+===================
+The counterpart to this gadget is the fastboot client which can
+be found in Android's platform/system/core repository in the fastboot
+folder. It runs on Windows, Linux and even OSX. Linux user are lucky since
+they only need libusb.
+Windows users need to bring some time until they have Android SDK (currently
+http://dl.google.com/android/installer_r12-windows.exe) installed. You
+need to install ADB package which contains the required glue libraries for
+accessing USB. Also you need "Google USB driver package" and "SDK platform
+tools". Once installed the usb driver is placed in your SDK folder under
+extras\google\usb_driver. The android_winusb.inf needs a line like
+
+   %SingleBootLoaderInterface% = USB_Install, USB\VID_0451&PID_D022
+
+either in the [Google.NTx86] section for 32bit Windows or [Google.NTamd64]
+for 64bit Windows. VID and PID should match whatever the fastboot is
+advertising.
+
+Board specific
+==============
+The fastboot gadget relies on the USB download gadget, so the following
+options must be configured:
+
+CONFIG_USBDOWNLOAD_GADGET
+CONFIG_G_DNL_VENDOR_NUM
+CONFIG_G_DNL_PRODUCT_NUM
+CONFIG_G_DNL_MANUFACTURER
+
+The fastboot function is enabled by defining CONFIG_CMD_FASTBOOT and
+CONFIG_ANDROID_BOOT_IMAGE.
+
+The fastboot protocol requires a large memory buffer for downloads. This
+buffer should be as large as possible for a platform. The location of the
+buffer and size are set with CONFIG_USB_FASTBOOT_BUF_ADDR and
+CONFIG_USB_FASTBOOT_BUF_SIZE.
+
+In Action
+=========
+Enter into fastboot by executing the fastboot command in u-boot and you
+should see:
+|GADGET DRIVER: usb_dnl_fastboot
+
+On the client side you can fetch the bootloader version for instance:
+|>fastboot getvar bootloader-version
+|bootloader-version: U-Boot 2014.04-00005-gd24cabc
+|finished. total time: 0.000s
+
+or initiate a reboot:
+|>fastboot reboot
+
+and once the client comes back, the board should reset.
+
+You can also specify a kernel image to boot. You have to either specify
+the an image in Android format _or_ pass a binary kernel and let the
+fastboot client wrap the Android suite around it. On OMAP for instance you
+take zImage kernel and pass it to the fastboot client:
+
+|>fastboot -b 0x80000000 -c "console=ttyO2 earlyprintk root=/dev/ram0
+|      mem=128M" boot zImage
+|creating boot image...
+|creating boot image - 1847296 bytes
+|downloading 'boot.img'...
+|OKAY [  2.766s]
+|booting...
+|OKAY [ -0.000s]
+|finished. total time: 2.766s
+
+and on the gadget side you should see:
+|Starting download of 1847296 bytes
+|........................................................
+|downloading of 1847296 bytes finished
+|Booting kernel..
+|## Booting Android Image at 0x81000000 ...
+|Kernel load addr 0x80008000 size 1801 KiB
+|Kernel command line: console=ttyO2 earlyprintk root=/dev/ram0 mem=128M
+|   Loading Kernel Image ... OK
+|OK
+|
+|Starting kernel ...
diff --git a/doc/README.android-fastboot-protocol b/doc/README.android-fastboot-protocol
new file mode 100644 (file)
index 0000000..e9e7166
--- /dev/null
@@ -0,0 +1,170 @@
+FastBoot  Version  0.4
+----------------------
+
+The fastboot protocol is a mechanism for communicating with bootloaders
+over USB.  It is designed to be very straightforward to implement, to
+allow it to be used across a wide range of devices and from hosts running
+Linux, Windows, or OSX.
+
+
+Basic Requirements
+------------------
+
+* Two bulk endpoints (in, out) are required
+* Max packet size must be 64 bytes for full-speed and 512 bytes for
+  high-speed USB
+* The protocol is entirely host-driven and synchronous (unlike the
+  multi-channel, bi-directional, asynchronous ADB protocol)
+
+
+Transport and Framing
+---------------------
+
+1. Host sends a command, which is an ascii string in a single
+   packet no greater than 64 bytes.
+
+2. Client response with a single packet no greater than 64 bytes.
+   The first four bytes of the response are "OKAY", "FAIL", "DATA",
+   or "INFO".  Additional bytes may contain an (ascii) informative
+   message.
+
+   a. INFO -> the remaining 60 bytes are an informative message
+      (providing progress or diagnostic messages).  They should
+      be displayed and then step #2 repeats
+
+   b. FAIL -> the requested command failed.  The remaining 60 bytes
+      of the response (if present) provide a textual failure message
+      to present to the user.  Stop.
+
+   c. OKAY -> the requested command completed successfully.  Go to #5
+
+   d. DATA -> the requested command is ready for the data phase.
+      A DATA response packet will be 12 bytes long, in the form of
+      DATA00000000 where the 8 digit hexidecimal number represents
+      the total data size to transfer.
+
+3. Data phase.  Depending on the command, the host or client will
+   send the indicated amount of data.  Short packets are always
+   acceptable and zero-length packets are ignored.  This phase continues
+   until the client has sent or received the number of bytes indicated
+   in the "DATA" response above.
+
+4. Client responds with a single packet no greater than 64 bytes.
+   The first four bytes of the response are "OKAY", "FAIL", or "INFO".
+   Similar to #2:
+
+   a. INFO -> display the remaining 60 bytes and return to #4
+
+   b. FAIL -> display the remaining 60 bytes (if present) as a failure
+      reason and consider the command failed.  Stop.
+
+   c. OKAY -> success.  Go to #5
+
+5. Success.  Stop.
+
+
+Example Session
+---------------
+
+Host:    "getvar:version"        request version variable
+
+Client:  "OKAY0.4"               return version "0.4"
+
+Host:    "getvar:nonexistant"    request some undefined variable
+
+Client:  "OKAY"                  return value ""
+
+Host:    "download:00001234"     request to send 0x1234 bytes of data
+
+Client:  "DATA00001234"          ready to accept data
+
+Host:    < 0x1234 bytes >        send data
+
+Client:  "OKAY"                  success
+
+Host:    "flash:bootloader"      request to flash the data to the bootloader
+
+Client:  "INFOerasing flash"     indicate status / progress
+         "INFOwriting flash"
+         "OKAY"                  indicate success
+
+Host:    "powerdown"             send a command
+
+Client:  "FAILunknown command"   indicate failure
+
+
+Command Reference
+-----------------
+
+* Command parameters are indicated by printf-style escape sequences.
+
+* Commands are ascii strings and sent without the quotes (which are
+  for illustration only here) and without a trailing 0 byte.
+
+* Commands that begin with a lowercase letter are reserved for this
+  specification.  OEM-specific commands should not begin with a
+  lowercase letter, to prevent incompatibilities with future specs.
+
+ "getvar:%s"           Read a config/version variable from the bootloader.
+                       The variable contents will be returned after the
+                       OKAY response.
+
+ "download:%08x"       Write data to memory which will be later used
+                       by "boot", "ramdisk", "flash", etc.  The client
+                       will reply with "DATA%08x" if it has enough
+                       space in RAM or "FAIL" if not.  The size of
+                       the download is remembered.
+
+  "verify:%08x"        Send a digital signature to verify the downloaded
+                       data.  Required if the bootloader is "secure"
+                       otherwise "flash" and "boot" will be ignored.
+
+  "flash:%s"           Write the previously downloaded image to the
+                       named partition (if possible).
+
+  "erase:%s"           Erase the indicated partition (clear to 0xFFs)
+
+  "boot"               The previously downloaded data is a boot.img
+                       and should be booted according to the normal
+                       procedure for a boot.img
+
+  "continue"           Continue booting as normal (if possible)
+
+  "reboot"             Reboot the device.
+
+  "reboot-bootloader"  Reboot back into the bootloader.
+                       Useful for upgrade processes that require upgrading
+                       the bootloader and then upgrading other partitions
+                       using the new bootloader.
+
+  "powerdown"          Power off the device.
+
+
+
+Client Variables
+----------------
+
+The "getvar:%s" command is used to read client variables which
+represent various information about the device and the software
+on it.
+
+The various currently defined names are:
+
+  version             Version of FastBoot protocol supported.
+                      It should be "0.3" for this document.
+
+  version-bootloader  Version string for the Bootloader.
+
+  version-baseband    Version string of the Baseband Software
+
+  product             Name of the product
+
+  serialno            Product serial number
+
+  secure              If the value is "yes", this is a secure
+                      bootloader requiring a signature before
+                      it will install or boot images.
+
+Names starting with a lowercase character are reserved by this
+specification.  OEM-specific names should not start with lowercase
+characters.
index 896c8d407e4ba0dacaefa7d1c737164a75f05ea3..66becdc78226a942ccc1a621787e1ef2c0888fc7 100644 (file)
@@ -18,6 +18,7 @@ obj-$(CONFIG_THOR_FUNCTION) += f_thor.o
 obj-$(CONFIG_USBDOWNLOAD_GADGET) += g_dnl.o
 obj-$(CONFIG_DFU_FUNCTION) += f_dfu.o
 obj-$(CONFIG_USB_GADGET_MASS_STORAGE) += f_mass_storage.o
+obj-$(CONFIG_CMD_FASTBOOT) += f_fastboot.o
 endif
 ifdef CONFIG_USB_ETHER
 obj-y += ether.o
diff --git a/drivers/usb/gadget/f_fastboot.c b/drivers/usb/gadget/f_fastboot.c
new file mode 100644 (file)
index 0000000..9dd85b6
--- /dev/null
@@ -0,0 +1,513 @@
+/*
+ * (C) Copyright 2008 - 2009
+ * Windriver, <www.windriver.com>
+ * Tom Rix <Tom.Rix@windriver.com>
+ *
+ * Copyright 2011 Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+ *
+ * Copyright 2014 Linaro, Ltd.
+ * Rob Herring <robh@kernel.org>
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+#include <common.h>
+#include <errno.h>
+#include <malloc.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/gadget.h>
+#include <linux/usb/composite.h>
+#include <linux/compiler.h>
+#include <version.h>
+#include <g_dnl.h>
+
+#define FASTBOOT_VERSION               "0.4"
+
+#define FASTBOOT_INTERFACE_CLASS       0xff
+#define FASTBOOT_INTERFACE_SUB_CLASS   0x42
+#define FASTBOOT_INTERFACE_PROTOCOL    0x03
+
+#define RX_ENDPOINT_MAXIMUM_PACKET_SIZE_2_0  (0x0200)
+#define RX_ENDPOINT_MAXIMUM_PACKET_SIZE_1_1  (0x0040)
+#define TX_ENDPOINT_MAXIMUM_PACKET_SIZE      (0x0040)
+
+/* The 64 defined bytes plus \0 */
+#define RESPONSE_LEN   (64 + 1)
+
+#define EP_BUFFER_SIZE                 4096
+
+struct f_fastboot {
+       struct usb_function usb_function;
+
+       /* IN/OUT EP's and correspoinding requests */
+       struct usb_ep *in_ep, *out_ep;
+       struct usb_request *in_req, *out_req;
+};
+
+static inline struct f_fastboot *func_to_fastboot(struct usb_function *f)
+{
+       return container_of(f, struct f_fastboot, usb_function);
+}
+
+static struct f_fastboot *fastboot_func;
+static unsigned int download_size;
+static unsigned int download_bytes;
+
+static struct usb_endpoint_descriptor fs_ep_in = {
+       .bLength            = USB_DT_ENDPOINT_SIZE,
+       .bDescriptorType    = USB_DT_ENDPOINT,
+       .bEndpointAddress   = USB_DIR_IN,
+       .bmAttributes       = USB_ENDPOINT_XFER_BULK,
+       .wMaxPacketSize     = TX_ENDPOINT_MAXIMUM_PACKET_SIZE,
+       .bInterval          = 0x00,
+};
+
+static struct usb_endpoint_descriptor fs_ep_out = {
+       .bLength                = USB_DT_ENDPOINT_SIZE,
+       .bDescriptorType        = USB_DT_ENDPOINT,
+       .bEndpointAddress       = USB_DIR_OUT,
+       .bmAttributes           = USB_ENDPOINT_XFER_BULK,
+       .wMaxPacketSize         = RX_ENDPOINT_MAXIMUM_PACKET_SIZE_1_1,
+       .bInterval              = 0x00,
+};
+
+static struct usb_endpoint_descriptor hs_ep_out = {
+       .bLength                = USB_DT_ENDPOINT_SIZE,
+       .bDescriptorType        = USB_DT_ENDPOINT,
+       .bEndpointAddress       = USB_DIR_OUT,
+       .bmAttributes           = USB_ENDPOINT_XFER_BULK,
+       .wMaxPacketSize         = RX_ENDPOINT_MAXIMUM_PACKET_SIZE_2_0,
+       .bInterval              = 0x00,
+};
+
+static struct usb_interface_descriptor interface_desc = {
+       .bLength                = USB_DT_INTERFACE_SIZE,
+       .bDescriptorType        = USB_DT_INTERFACE,
+       .bInterfaceNumber       = 0x00,
+       .bAlternateSetting      = 0x00,
+       .bNumEndpoints          = 0x02,
+       .bInterfaceClass        = FASTBOOT_INTERFACE_CLASS,
+       .bInterfaceSubClass     = FASTBOOT_INTERFACE_SUB_CLASS,
+       .bInterfaceProtocol     = FASTBOOT_INTERFACE_PROTOCOL,
+};
+
+static struct usb_descriptor_header *fb_runtime_descs[] = {
+       (struct usb_descriptor_header *)&interface_desc,
+       (struct usb_descriptor_header *)&fs_ep_in,
+       (struct usb_descriptor_header *)&hs_ep_out,
+       NULL,
+};
+
+/*
+ * static strings, in UTF-8
+ */
+static const char fastboot_name[] = "Android Fastboot";
+
+static struct usb_string fastboot_string_defs[] = {
+       [0].s = fastboot_name,
+       {  }                    /* end of list */
+};
+
+static struct usb_gadget_strings stringtab_fastboot = {
+       .language       = 0x0409,       /* en-us */
+       .strings        = fastboot_string_defs,
+};
+
+static struct usb_gadget_strings *fastboot_strings[] = {
+       &stringtab_fastboot,
+       NULL,
+};
+
+static void rx_handler_command(struct usb_ep *ep, struct usb_request *req);
+
+static void fastboot_complete(struct usb_ep *ep, struct usb_request *req)
+{
+       int status = req->status;
+       if (!status)
+               return;
+       printf("status: %d ep '%s' trans: %d\n", status, ep->name, req->actual);
+}
+
+static int fastboot_bind(struct usb_configuration *c, struct usb_function *f)
+{
+       int id;
+       struct usb_gadget *gadget = c->cdev->gadget;
+       struct f_fastboot *f_fb = func_to_fastboot(f);
+
+       /* DYNAMIC interface numbers assignments */
+       id = usb_interface_id(c, f);
+       if (id < 0)
+               return id;
+       interface_desc.bInterfaceNumber = id;
+
+       id = usb_string_id(c->cdev);
+       if (id < 0)
+               return id;
+       fastboot_string_defs[0].id = id;
+       interface_desc.iInterface = id;
+
+       f_fb->in_ep = usb_ep_autoconfig(gadget, &fs_ep_in);
+       if (!f_fb->in_ep)
+               return -ENODEV;
+       f_fb->in_ep->driver_data = c->cdev;
+
+       f_fb->out_ep = usb_ep_autoconfig(gadget, &fs_ep_out);
+       if (!f_fb->out_ep)
+               return -ENODEV;
+       f_fb->out_ep->driver_data = c->cdev;
+
+       hs_ep_out.bEndpointAddress = fs_ep_out.bEndpointAddress;
+
+       return 0;
+}
+
+static void fastboot_unbind(struct usb_configuration *c, struct usb_function *f)
+{
+       memset(fastboot_func, 0, sizeof(*fastboot_func));
+}
+
+static void fastboot_disable(struct usb_function *f)
+{
+       struct f_fastboot *f_fb = func_to_fastboot(f);
+
+       usb_ep_disable(f_fb->out_ep);
+       usb_ep_disable(f_fb->in_ep);
+
+       if (f_fb->out_req) {
+               free(f_fb->out_req->buf);
+               usb_ep_free_request(f_fb->out_ep, f_fb->out_req);
+               f_fb->out_req = NULL;
+       }
+       if (f_fb->in_req) {
+               free(f_fb->in_req->buf);
+               usb_ep_free_request(f_fb->in_ep, f_fb->in_req);
+               f_fb->in_req = NULL;
+       }
+}
+
+static struct usb_request *fastboot_start_ep(struct usb_ep *ep)
+{
+       struct usb_request *req;
+
+       req = usb_ep_alloc_request(ep, 0);
+       if (!req)
+               return NULL;
+
+       req->length = EP_BUFFER_SIZE;
+       req->buf = memalign(CONFIG_SYS_CACHELINE_SIZE, EP_BUFFER_SIZE);
+       if (!req->buf) {
+               usb_ep_free_request(ep, req);
+               return NULL;
+       }
+
+       memset(req->buf, 0, req->length);
+       return req;
+}
+
+static int fastboot_set_alt(struct usb_function *f,
+                           unsigned interface, unsigned alt)
+{
+       int ret;
+       struct usb_composite_dev *cdev = f->config->cdev;
+       struct usb_gadget *gadget = cdev->gadget;
+       struct f_fastboot *f_fb = func_to_fastboot(f);
+
+       debug("%s: func: %s intf: %d alt: %d\n",
+             __func__, f->name, interface, alt);
+
+       /* make sure we don't enable the ep twice */
+       if (gadget->speed == USB_SPEED_HIGH)
+               ret = usb_ep_enable(f_fb->out_ep, &hs_ep_out);
+       else
+               ret = usb_ep_enable(f_fb->out_ep, &fs_ep_out);
+       if (ret) {
+               puts("failed to enable out ep\n");
+               return ret;
+       }
+
+       f_fb->out_req = fastboot_start_ep(f_fb->out_ep);
+       if (!f_fb->out_req) {
+               puts("failed to alloc out req\n");
+               ret = -EINVAL;
+               goto err;
+       }
+       f_fb->out_req->complete = rx_handler_command;
+
+       ret = usb_ep_enable(f_fb->in_ep, &fs_ep_in);
+       if (ret) {
+               puts("failed to enable in ep\n");
+               goto err;
+       }
+
+       f_fb->in_req = fastboot_start_ep(f_fb->in_ep);
+       if (!f_fb->in_req) {
+               puts("failed alloc req in\n");
+               ret = -EINVAL;
+               goto err;
+       }
+       f_fb->in_req->complete = fastboot_complete;
+
+       ret = usb_ep_queue(f_fb->out_ep, f_fb->out_req, 0);
+       if (ret)
+               goto err;
+
+       return 0;
+err:
+       fastboot_disable(f);
+       return ret;
+}
+
+static int fastboot_add(struct usb_configuration *c)
+{
+       struct f_fastboot *f_fb = fastboot_func;
+       int status;
+
+       debug("%s: cdev: 0x%p\n", __func__, c->cdev);
+
+       if (!f_fb) {
+               f_fb = memalign(CONFIG_SYS_CACHELINE_SIZE, sizeof(*f_fb));
+               if (!f_fb)
+                       return -ENOMEM;
+
+               fastboot_func = f_fb;
+               memset(f_fb, 0, sizeof(*f_fb));
+       }
+
+       f_fb->usb_function.name = "f_fastboot";
+       f_fb->usb_function.hs_descriptors = fb_runtime_descs;
+       f_fb->usb_function.bind = fastboot_bind;
+       f_fb->usb_function.unbind = fastboot_unbind;
+       f_fb->usb_function.set_alt = fastboot_set_alt;
+       f_fb->usb_function.disable = fastboot_disable;
+       f_fb->usb_function.strings = fastboot_strings;
+
+       status = usb_add_function(c, &f_fb->usb_function);
+       if (status) {
+               free(f_fb);
+               fastboot_func = f_fb;
+       }
+
+       return status;
+}
+DECLARE_GADGET_BIND_CALLBACK(usb_dnl_fastboot, fastboot_add);
+
+int fastboot_tx_write(const char *buffer, unsigned int buffer_size)
+{
+       struct usb_request *in_req = fastboot_func->in_req;
+       int ret;
+
+       memcpy(in_req->buf, buffer, buffer_size);
+       in_req->length = buffer_size;
+       ret = usb_ep_queue(fastboot_func->in_ep, in_req, 0);
+       if (ret)
+               printf("Error %d on queue\n", ret);
+       return 0;
+}
+
+static int fastboot_tx_write_str(const char *buffer)
+{
+       return fastboot_tx_write(buffer, strlen(buffer));
+}
+
+static void compl_do_reset(struct usb_ep *ep, struct usb_request *req)
+{
+       do_reset(NULL, 0, 0, NULL);
+}
+
+static void cb_reboot(struct usb_ep *ep, struct usb_request *req)
+{
+       fastboot_func->in_req->complete = compl_do_reset;
+       fastboot_tx_write_str("OKAY");
+}
+
+static int strcmp_l1(const char *s1, const char *s2)
+{
+       if (!s1 || !s2)
+               return -1;
+       return strncmp(s1, s2, strlen(s1));
+}
+
+static void cb_getvar(struct usb_ep *ep, struct usb_request *req)
+{
+       char *cmd = req->buf;
+       char response[RESPONSE_LEN];
+       const char *s;
+
+       strcpy(response, "OKAY");
+       strsep(&cmd, ":");
+       if (!cmd) {
+               fastboot_tx_write_str("FAILmissing var");
+               return;
+       }
+
+       if (!strcmp_l1("version", cmd)) {
+               strncat(response, FASTBOOT_VERSION, sizeof(response));
+       } else if (!strcmp_l1("bootloader-version", cmd)) {
+               strncat(response, U_BOOT_VERSION, sizeof(response));
+       } else if (!strcmp_l1("downloadsize", cmd)) {
+               char str_num[12];
+
+               sprintf(str_num, "%08x", CONFIG_USB_FASTBOOT_BUF_SIZE);
+               strncat(response, str_num, sizeof(response));
+       } else if (!strcmp_l1("serialno", cmd)) {
+               s = getenv("serial#");
+               if (s)
+                       strncat(response, s, sizeof(response));
+               else
+                       strcpy(response, "FAILValue not set");
+       } else {
+               strcpy(response, "FAILVariable not implemented");
+       }
+       fastboot_tx_write_str(response);
+}
+
+static unsigned int rx_bytes_expected(void)
+{
+       int rx_remain = download_size - download_bytes;
+       if (rx_remain < 0)
+               return 0;
+       if (rx_remain > EP_BUFFER_SIZE)
+               return EP_BUFFER_SIZE;
+       return rx_remain;
+}
+
+#define BYTES_PER_DOT  0x20000
+static void rx_handler_dl_image(struct usb_ep *ep, struct usb_request *req)
+{
+       char response[RESPONSE_LEN];
+       unsigned int transfer_size = download_size - download_bytes;
+       const unsigned char *buffer = req->buf;
+       unsigned int buffer_size = req->actual;
+
+       if (req->status != 0) {
+               printf("Bad status: %d\n", req->status);
+               return;
+       }
+
+       if (buffer_size < transfer_size)
+               transfer_size = buffer_size;
+
+       memcpy((void *)CONFIG_USB_FASTBOOT_BUF_ADDR + download_bytes,
+              buffer, transfer_size);
+
+       download_bytes += transfer_size;
+
+       /* Check if transfer is done */
+       if (download_bytes >= download_size) {
+               /*
+                * Reset global transfer variable, keep download_bytes because
+                * it will be used in the next possible flashing command
+                */
+               download_size = 0;
+               req->complete = rx_handler_command;
+               req->length = EP_BUFFER_SIZE;
+
+               sprintf(response, "OKAY");
+               fastboot_tx_write_str(response);
+
+               printf("\ndownloading of %d bytes finished\n", download_bytes);
+       } else {
+               req->length = rx_bytes_expected();
+               if (req->length < ep->maxpacket)
+                       req->length = ep->maxpacket;
+       }
+
+       if (download_bytes && !(download_bytes % BYTES_PER_DOT)) {
+               putc('.');
+               if (!(download_bytes % (74 * BYTES_PER_DOT)))
+                       putc('\n');
+       }
+       req->actual = 0;
+       usb_ep_queue(ep, req, 0);
+}
+
+static void cb_download(struct usb_ep *ep, struct usb_request *req)
+{
+       char *cmd = req->buf;
+       char response[RESPONSE_LEN];
+
+       strsep(&cmd, ":");
+       download_size = simple_strtoul(cmd, NULL, 16);
+       download_bytes = 0;
+
+       printf("Starting download of %d bytes\n", download_size);
+
+       if (0 == download_size) {
+               sprintf(response, "FAILdata invalid size");
+       } else if (download_size > CONFIG_USB_FASTBOOT_BUF_SIZE) {
+               download_size = 0;
+               sprintf(response, "FAILdata too large");
+       } else {
+               sprintf(response, "DATA%08x", download_size);
+               req->complete = rx_handler_dl_image;
+               req->length = rx_bytes_expected();
+               if (req->length < ep->maxpacket)
+                       req->length = ep->maxpacket;
+       }
+       fastboot_tx_write_str(response);
+}
+
+static void do_bootm_on_complete(struct usb_ep *ep, struct usb_request *req)
+{
+       char boot_addr_start[12];
+       char *bootm_args[] = { "bootm", boot_addr_start, NULL };
+
+       puts("Booting kernel..\n");
+
+       sprintf(boot_addr_start, "0x%lx", load_addr);
+       do_bootm(NULL, 0, 2, bootm_args);
+
+       /* This only happens if image is somehow faulty so we start over */
+       do_reset(NULL, 0, 0, NULL);
+}
+
+static void cb_boot(struct usb_ep *ep, struct usb_request *req)
+{
+       fastboot_func->in_req->complete = do_bootm_on_complete;
+       fastboot_tx_write_str("OKAY");
+}
+
+struct cmd_dispatch_info {
+       char *cmd;
+       void (*cb)(struct usb_ep *ep, struct usb_request *req);
+};
+
+static const struct cmd_dispatch_info cmd_dispatch_info[] = {
+       {
+               .cmd = "reboot",
+               .cb = cb_reboot,
+       }, {
+               .cmd = "getvar:",
+               .cb = cb_getvar,
+       }, {
+               .cmd = "download:",
+               .cb = cb_download,
+       }, {
+               .cmd = "boot",
+               .cb = cb_boot,
+       },
+};
+
+static void rx_handler_command(struct usb_ep *ep, struct usb_request *req)
+{
+       char *cmdbuf = req->buf;
+       void (*func_cb)(struct usb_ep *ep, struct usb_request *req) = NULL;
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(cmd_dispatch_info); i++) {
+               if (!strcmp_l1(cmd_dispatch_info[i].cmd, cmdbuf)) {
+                       func_cb = cmd_dispatch_info[i].cb;
+                       break;
+               }
+       }
+
+       if (!func_cb)
+               fastboot_tx_write_str("FAILunknown command");
+       else
+               func_cb(ep, req);
+
+       if (req->status == 0) {
+               *cmdbuf = '\0';
+               req->actual = 0;
+               usb_ep_queue(ep, req, 0);
+       }
+}