[U-Boot] [PATCH v3 4/5] usb/gadget: add the fastboot gadget

Lukasz Majewski
2014-04-15T15:41:55Z

Hi Rob,

> From: Sebastian Siewior <bigeasy@linutronix.de>
>
> This patch contains an implementation of the fastboot protocol on the
> device side and a little of documentation.
> The gadget expects the new-style gadget framework.
> The gadget 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

I could only propose to use common g_dnl.c code with CONFIG_G_DNL_*
defines.

> - Set vendor/product ID from config defines
> - Allow Ctrl-C to exit fastboot mode
>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> Signed-off-by: Rob Herring <robh@kernel.org>
> ---
> common/Makefile | 2 +
> common/cmd_fastboot.c | 36 +++
> doc/README.android-fastboot | 86 ++++++
> doc/README.android-fastboot-protocol | 170 +++++++++++
> drivers/usb/gadget/Makefile | 1 +
> drivers/usb/gadget/f_fastboot.c | 535
> +++++++++++++++++++++++++++++++++++
> drivers/usb/gadget/g_fastboot.h | 15 +
> drivers/usb/gadget/u_fastboot.c | 260 +++++++++++++++++
> include/usb/fastboot.h | 36 +++ 9 files changed, 1141
> insertions(+) create mode 100644 common/cmd_fastboot.c
> create mode 100644 doc/README.android-fastboot
> create mode 100644 doc/README.android-fastboot-protocol
> create mode 100644 drivers/usb/gadget/f_fastboot.c
> create mode 100644 drivers/usb/gadget/g_fastboot.h
> create mode 100644 drivers/usb/gadget/u_fastboot.c
> create mode 100644 include/usb/fastboot.h
>
> diff --git a/common/Makefile b/common/Makefile
> index da208f3..fe1d8b9 100644
> --- a/common/Makefile
> +++ b/common/Makefile
> @@ -167,6 +167,8 @@ 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
> index 0000000..fc8d9e0
> --- /dev/null
> +++ b/common/cmd_fastboot.c
> @@ -0,0 +1,36 @@
> +/*
> + * Copyright 2008 - 2009 Windriver, <www.windriver.com>
> + * Author: Tom Rix <Tom.Rix@windriver.com>
> + *
> + * SPDX-License-Identifier: GPL-2.0+
> + */
> +#include <common.h>
> +#include <command.h>
> +#include <usb/fastboot.h>
> +
> +static int do_fastboot(cmd_tbl_t *cmdtp, int flag, int argc, char
> *const argv[]) +{
> + int ret = 1;
> +
> + if (!fastboot_init()) {
> + printf("Fastboot entered...\n");

Please use puts();
> +
> + ret = 0;
> +
> + while (1) {
> + if (fastboot_poll())
> + break;
> + if (ctrlc())
> + break;
> + }
> + }
> +
> + fastboot_shutdown();
> + return ret;
> +}

For the fastboot command you could use the common gadget download code
(g_dnl.c). For reference please look into common/cmd_dfu.c

> +
> +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
> index 0000000..4b2a9aa
> --- /dev/null
> +++ b/doc/README.android-fastboot
> @@ -0,0 +1,86 @@
> +Android Fastboot
> +~~~~~~~~~~~~~~~~
> +
> +Overview
> +========
> +The protocol that is used over USB is described in
> +README.android-fastboot-protocol in same folder.
> +
> +The current implementation does not yet support the flash and erase
> +commands.

Flashing of received data can be performed with common dfu_write()
method.

> +
> +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 gadget calls at probe time the function fastboot_board_init()
> which +should be provided by the board to setup its specific
> configuration. +It is possible here to overwrite specific strings
> like Vendor or Serial +number. Strings which are not specified here
> will return a default value. +This init function must also provide a
> memory area for the +"transfer_buffer" and its size. This buffer
> should be large enough to hold +whatever the download commands is
> willing to send or it will fail. This +can be a kernel image for
> booting which could be around two MiB or a flash +partition which
> could be slightly larger :) +

With the write backend (dfu.c) you can specify the buffer size with
dfu_bufsiz env variable.

> +In Action
> +=========
> +Enter into fastboot by executing the fastboot command in u-boot and
> you +should see:
> +|Fastboot entered...
> +
> +The gadget terminates once the is unplugged. On the client side you
> can +fetch the product name for instance:
> +|>fastboot getvar product
> +|product: Default Product
> +|finished. total time: 0.016s
> +
> +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
> index 0000000..e9e7166
> --- /dev/null
> +++ b/doc/README.android-fastboot-protocol
> @@ -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.
> +
> +

It is a very nice mix of commands and downloading data. Frankly, I'm
quite interested if there is support for "upload" command available (or
easily implementable)? It seems, like it is also not possible to
execute an arbitrary command from a set supported by the u-boot
bootloader.

I'm asking because protocol with such features, would greatly facilitate
automated testing for u-boot running on a particular HW.

> +
> +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.
> diff --git a/drivers/usb/gadget/Makefile b/drivers/usb/gadget/Makefile
> index 804a2bd..b14f60e 100644
> --- a/drivers/usb/gadget/Makefile
> +++ b/drivers/usb/gadget/Makefile
> @@ -17,6 +17,7 @@ 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 u_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
> index 0000000..f74a52e
> --- /dev/null
> +++ b/drivers/usb/gadget/f_fastboot.c
> @@ -0,0 +1,535 @@
> +/*
> + * (C) Copyright 2008 - 2009
> + * Windriver, <www.windriver.com>
> + * Tom Rix <Tom.Rix@windriver.com>
> + *
> + * Copyright 2011 Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> + *
> + * SPDX-License-Identifier: GPL-2.0+
> + */
> +#include <common.h>
> +#include <errno.h>
> +#include <usb/fastboot.h>
> +#include <linux/usb/ch9.h>
> +#include <linux/usb/gadget.h>
> +#include <linux/compiler.h>
> +
> +#include "g_fastboot.h"
> +
> +#define FASTBOOT_INTERFACE_CLASS 0xff
> +#define FASTBOOT_INTERFACE_SUB_CLASS 0x42
> +#define FASTBOOT_INTERFACE_PROTOCOL 0x03
> +
> +#define CONFIGURATION_NORMAL 1
> +#define BULK_ENDPOINT 1
> +#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)
> +
> +static struct usb_string def_usb_fb_strings[] = {
> + { FB_STR_PRODUCT_IDX, "Default Product" },
> + { FB_STR_SERIAL_IDX, "1234567890" },
> + { FB_STR_CONFIG_IDX, "Android Fastboot" },
> + { FB_STR_INTERFACE_IDX, "Android Fastboot" },
> + { FB_STR_MANUFACTURER_IDX, "Default Manufacturer" },
> + { FB_STR_PROC_REV_IDX, "Default 1.0" },
> + { FB_STR_PROC_TYPE_IDX, "Emulator" },
> + { }
> +};

Such structure in a more generic way is defined at g_dnl.c file.

> +
> +static struct usb_gadget_strings def_fb_strings = {
> + .language = 0x0409, /* en-us */
> + .strings = def_usb_fb_strings,
> +};
> +
> +static struct usb_gadget_strings *vendor_fb_strings;
> +
> +static unsigned int gadget_is_connected;
> +

You would probably need DEFINE_CACHE_ALIGN_BUFFER() here to avoid
problems with cache coherency.

> +static u8 ep0_buffer[512];
> +static u8 ep_out_buffer[EP_BUFFER_SIZE];
> +static u8 ep_in_buffer[EP_BUFFER_SIZE];
> +static int current_config;
> +
> +/* e1 */
> +static struct usb_endpoint_descriptor fs_ep_in = {
> + .bLength = USB_DT_ENDPOINT_SIZE,
> + .bDescriptorType = USB_DT_ENDPOINT,
> + .bEndpointAddress = USB_DIR_IN, /* IN */
> + .bmAttributes = USB_ENDPOINT_XFER_BULK,
> + .wMaxPacketSize = TX_ENDPOINT_MAXIMUM_PACKET_SIZE,
> + .bInterval = 0x00,
> +};
> +
> +/* e2 */
> +static struct usb_endpoint_descriptor fs_ep_out = {
> + .bLength = USB_DT_ENDPOINT_SIZE,
> + .bDescriptorType = USB_DT_ENDPOINT,
> + .bEndpointAddress = USB_DIR_OUT, /* 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, /* OUT */
> + .bmAttributes = USB_ENDPOINT_XFER_BULK,
> + .wMaxPacketSize =
> RX_ENDPOINT_MAXIMUM_PACKET_SIZE_2_0,
> + .bInterval = 0x00,
> +};
> +
> +const char *fb_find_usb_string(unsigned int id)
> +{
> + struct usb_string *s = NULL;
> +
> + if (vendor_fb_strings) {
> + for (s = vendor_fb_strings->strings; s && s->s; s++)
> {
> + if (s->id == id)
> + break;
> + }
> + }
> + if (!s || !s->s) {
> + for (s = def_fb_strings.strings; s && s->s; s++) {
> + if (s->id == id)
> + break;
> + }
> + }
> + if (!s)
> + return NULL;
> + return s->s;
> +}
> +
> +static struct usb_request *ep0_req;
> +
> +struct usb_ep *ep_in;
> +struct usb_request *req_in;
> +
> +struct usb_ep *ep_out;
> +struct usb_request *req_out;
> +
> +static void fastboot_ep0_complete(struct usb_ep *ep, struct
> usb_request *req) +{
> + int status = req->status;
> +
> + if (!status)
> + return;
> + printf("ep0 status %d\n", status);
> +}
> +
> +static int fastboot_bind(struct usb_gadget *gadget)
> +{
> + ep0_req = usb_ep_alloc_request(gadget->ep0, 0);
> + if (!ep0_req)
> + goto err;
> + ep0_req->buf = ep0_buffer;
> + ep0_req->complete = fastboot_ep0_complete;
> +
> + ep_in = usb_ep_autoconfig(gadget, &fs_ep_in);
> + if (!ep_in)
> + goto err;
> + ep_in->driver_data = ep_in;
> +
> + ep_out = usb_ep_autoconfig(gadget, &fs_ep_out);
> + if (!ep_out)
> + goto err;
> + ep_out->driver_data = ep_out;
> +
> + hs_ep_out.bEndpointAddress = fs_ep_out.bEndpointAddress;
> +
> + usb_gadget_connect(gadget);
> + gadget_is_connected = 1;
> +
> + return 0;
> +err:
> + return -1;
> +}
> +
> +static void fastboot_unbind(struct usb_gadget *gadget)
> +{
> + usb_ep_free_request(gadget->ep0, ep0_req);
> + ep_in->driver_data = NULL;
> + ep_out->driver_data = NULL;
> +
> + gadget_is_connected = 0;
> + usb_gadget_disconnect(gadget);
> +}
> +
> +#define DEVICE_BCD 0x0100
> +
> +struct usb_device_descriptor fb_descriptor = {
> + .bLength = sizeof(fb_descriptor),
> + .bDescriptorType = USB_DT_DEVICE,
> + .bcdUSB = 0x200,
> + .bMaxPacketSize0 = 0x40,
> + .idVendor =
> cpu_to_le16(CONFIG_USB_FASTBOOT_VENDOR_ID),
> + .idProduct =
> cpu_to_le16(CONFIG_USB_FASTBOOT_PRODUCT_ID),
> + .bcdDevice = DEVICE_BCD,
> + .iManufacturer = FB_STR_MANUFACTURER_IDX,
> + .iProduct = FB_STR_PRODUCT_IDX,
> + .iSerialNumber = FB_STR_SERIAL_IDX,
> + .bNumConfigurations = 1,
> +};
> +
> +#define TOT_CFG_DESC_LEN (USB_DT_CONFIG_SIZE +
> USB_DT_INTERFACE_SIZE + \
> + USB_DT_ENDPOINT_SIZE + USB_DT_ENDPOINT_SIZE)
> +
> +static struct usb_config_descriptor config_desc = {
> + .bLength = USB_DT_CONFIG_SIZE,
> + .bDescriptorType = USB_DT_CONFIG,
> + .wTotalLength = cpu_to_le16(TOT_CFG_DESC_LEN),
> + .bNumInterfaces = 1,
> + .bConfigurationValue = CONFIGURATION_NORMAL,
> + .iConfiguration = FB_STR_CONFIG_IDX,
> + .bmAttributes = 0xc0,
> + .bMaxPower = 0x32,
> +};
> +
> +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,
> + .iInterface = FB_STR_INTERFACE_IDX,
> +};
> +
> +static struct usb_qualifier_descriptor qual_desc = {
> + .bLength = sizeof(qual_desc),
> + .bDescriptorType = USB_DT_DEVICE_QUALIFIER,
> + .bcdUSB = 0x200,
> + .bMaxPacketSize0 = 0x40,
> + .bNumConfigurations = 1,
> +};
> +
> +static int fastboot_setup_get_descr(struct usb_gadget *gadget,
> + const struct usb_ctrlrequest *ctrl)
> +{
> + u16 w_value = le16_to_cpu(ctrl->wValue);
> + u16 w_length = le16_to_cpu(ctrl->wLength);
> + u16 val;
> + int ret;
> + u32 bytes_remaining;
> + u32 bytes_total;
> + u32 this_inc;
> +
> + val = w_value >> 8;
> +
> + switch (val) {
> + case USB_DT_DEVICE:
> + memcpy(ep0_buffer, &fb_descriptor,
> sizeof(fb_descriptor));
> + ep0_req->length = min(w_length,
> sizeof(fb_descriptor));
> + ret = usb_ep_queue(gadget->ep0, ep0_req, 0);
> + break;
> + case USB_DT_CONFIG:
> + bytes_remaining = min(w_length, sizeof(ep0_buffer));
> + bytes_total = 0;
> +
> + /* config */
> + this_inc = min(bytes_remaining, USB_DT_CONFIG_SIZE);
> + bytes_remaining -= this_inc;
> + memcpy(ep0_buffer + bytes_total, &config_desc,
> this_inc);
> + bytes_total += this_inc;
> +
> + /* interface */
> + this_inc = min(bytes_remaining,
> USB_DT_INTERFACE_SIZE);
> + bytes_remaining -= this_inc;
> + memcpy(ep0_buffer + bytes_total, &interface_desc,
> this_inc);
> + bytes_total += this_inc;
> +
> + /* ep in */
> + this_inc = min(bytes_remaining,
> USB_DT_ENDPOINT_SIZE);
> + bytes_remaining -= this_inc;
> + memcpy(ep0_buffer + bytes_total, &fs_ep_in,
> this_inc);
> + bytes_total += this_inc;
> +
> + /* ep out */
> + this_inc = min(bytes_remaining,
> USB_DT_ENDPOINT_SIZE); +
> + if (gadget->speed == USB_SPEED_HIGH)
> + memcpy(ep0_buffer + bytes_total, &hs_ep_out,
> this_inc);
> + else
> + memcpy(ep0_buffer + bytes_total, &fs_ep_out,
> this_inc);
> + bytes_total += this_inc;
> +
> + ep0_req->length = bytes_total;
> + ret = usb_ep_queue(gadget->ep0, ep0_req, 0);
> + break;
> + case USB_DT_STRING:
> + ret = usb_gadget_get_string(vendor_fb_strings,
> + w_value & 0xff,
> ep0_buffer);
> + if (ret < 0)
> + ret = usb_gadget_get_string(&def_fb_strings,
> + w_value & 0xff,
> + ep0_buffer);
> + if (ret < 0)
> + break;
> +
> + ep0_req->length = ret;
> + ret = usb_ep_queue(gadget->ep0, ep0_req, 0);
> + break;
> + case USB_DT_DEVICE_QUALIFIER:
> + memcpy(ep0_buffer, &qual_desc, sizeof(qual_desc));
> + ep0_req->length = min(w_length, sizeof(qual_desc));
> + ret = usb_ep_queue(gadget->ep0, ep0_req, 0);
> + break;
> + default:
> + ret = -EINVAL;
> + }
> + return ret;
> +}

Here you use only the gadget API. In the THOR, UMS and DFU functions
such code is handled by the composite layer (composite.c) for all of
them.

> +
> +static int fastboot_setup_get_conf(struct usb_gadget *gadget,
> + const struct usb_ctrlrequest *ctrl)
> +{
> + u16 w_length = le16_to_cpu(ctrl->wLength);
> +
> + if (w_length == 0)
> + return -1;
> +
> + ep0_buffer[0] = current_config;
> + ep0_req->length = 1;
> + return usb_ep_queue(gadget->ep0, ep0_req, 0);
> +}
> +
> +static void fastboot_complete_in(struct usb_ep *ep, struct
> usb_request *req) +{
> + int status = req->status;
> +
> + if (status)
> + printf("status: %d ep_in trans: %d\n", status,
> req->actual); +}
> +
> +static int fastboot_disable_ep(struct usb_gadget *gadget)
> +{
> + if (req_out) {
> + usb_ep_free_request(ep_out, req_out);
> + req_out = NULL;
> + }
> + if (req_in) {
> + usb_ep_free_request(ep_in, req_in);
> + req_in = NULL;
> + }
> + usb_ep_disable(ep_out);
> + usb_ep_disable(ep_in);
> +
> + return 0;
> +}
> +
> +static int fastboot_enable_ep(struct usb_gadget *gadget)
> +{
> + int ret;
> +
> + /* make sure we don't enable the ep twice */
> + if (gadget->speed == USB_SPEED_HIGH)
> + ret = usb_ep_enable(ep_out, &hs_ep_out);
> + else
> + ret = usb_ep_enable(ep_out, &fs_ep_out);
> + if (ret) {
> + printf("failed to enable out ep\n");
> + goto err;
> + }
> +
> + req_out = usb_ep_alloc_request(ep_out, 0);
> + if (!req_out) {
> + printf("failed to alloc out req\n");
> + goto err;
> + }
> +
> + ret = usb_ep_enable(ep_in, &fs_ep_in);
> + if (ret) {
> + printf("failed to enable in ep\n");
> + goto err;
> + }
> + req_in = usb_ep_alloc_request(ep_in, 0);
> + if (!req_in) {
> + printf("failed alloc req in\n");
> + goto err;
> + }
> +
> + req_out->complete = rx_handler_command;
> + req_out->buf = ep_out_buffer;
> + req_out->length = sizeof(ep_out_buffer);
> +
> + req_in->buf = ep_in_buffer;
> + req_in->length = sizeof(ep_in_buffer);
> +
> + ret = usb_ep_queue(ep_out, req_out, 0);
> + if (ret)
> + goto err;
> +
> + return 0;
> +err:
> + fastboot_disable_ep(gadget);
> + return -1;
> +}
> +
> +static int fastboot_set_interface(struct usb_gadget *gadget, u32
> enable) +{
> + if (enable && req_out)
> + return 0;
> + if (!enable && !req_out)
> + return 0;
> +

^^^^^^^ maybe one if?

> + if (enable)
> + return fastboot_enable_ep(gadget);
> + else
> + return fastboot_disable_ep(gadget);
> +}
> +
> +static int fastboot_setup_out_req(struct usb_gadget *gadget,
> + const struct usb_ctrlrequest *req)
> +{
> + switch (req->bRequestType & USB_RECIP_MASK) {
> + case USB_RECIP_DEVICE:
> + switch (req->bRequest) {
> + case USB_REQ_SET_CONFIGURATION:
> +
> + ep0_req->length = 0;
> + if (req->wValue == CONFIGURATION_NORMAL) {
> + current_config =
> CONFIGURATION_NORMAL;
> + fastboot_set_interface(gadget, 1);
> + return usb_ep_queue(gadget->ep0,
> + ep0_req, 0);
> + }
> + if (req->wValue == 0) {
> + current_config = 0;
> + fastboot_set_interface(gadget, 0);
> + return usb_ep_queue(gadget->ep0,
> + ep0_req, 0);
> + }
> + return -1;

I always encourage people to return values from
<errno.h>

> + break;
> + default:
> + return -1;
> + };
> +
> + case USB_RECIP_INTERFACE:
> + switch (req->bRequest) {
> + case USB_REQ_SET_INTERFACE:
> +
> + ep0_req->length = 0;
> + if (!fastboot_set_interface(gadget, 1))
> + return usb_ep_queue(gadget->ep0,
> + ep0_req, 0);
> + return -1;
> + break;
> + default:
> + return -1;
> + }
> +
> + case USB_RECIP_ENDPOINT:
> + switch (req->bRequest) {
> + case USB_REQ_CLEAR_FEATURE:
> +
> + return usb_ep_queue(gadget->ep0, ep0_req, 0);
> + break;
> + default:
> + return -1;
> + }
> + }
> + return -1;
> +}
> +
> +static int fastboot_setup(struct usb_gadget *gadget,
> + const struct usb_ctrlrequest *req)
> +{
> + if ((req->bRequestType & USB_TYPE_MASK) != USB_TYPE_STANDARD)
> + return -1;
> +
> + if ((req->bRequestType & USB_DIR_IN) == 0)
> + /* host-to-device */
> + return fastboot_setup_out_req(gadget, req);
> +
> + /* device-to-host */
> + if ((req->bRequestType & USB_RECIP_MASK) ==
> USB_RECIP_DEVICE) {
> + switch (req->bRequest) {
> + case USB_REQ_GET_DESCRIPTOR:
> + return fastboot_setup_get_descr(gadget, req);
> + break;
> +
> + case USB_REQ_GET_CONFIGURATION:
> + return fastboot_setup_get_conf(gadget, req);
> + break;
> + default:
> + return -1;
> + }
> + }
> + return -1;
> +}
> +
> +static void fastboot_disconnect(struct usb_gadget *gadget)
> +{
> + fastboot_disable_ep(gadget);
> + gadget_is_connected = 0;
> +}
> +
> +struct usb_gadget_driver fast_gadget = {
> + .speed = USB_SPEED_HIGH,
> + .bind = fastboot_bind,
> + .unbind = fastboot_unbind,
> + .setup = fastboot_setup,
> + .disconnect = fastboot_disconnect,
> +};
> +
> +static int udc_is_probbed;
> +
> +int __weak fastboot_board_init(struct usb_gadget_strings **str)
> +{
> + return 0;
> +}
> +
> +int fastboot_init(void)
> +{
> + int ret;
> +
> + ret = fastboot_board_init(&vendor_fb_strings);
> + if (ret)
> + return ret;
> +
> + ret = usb_gadget_register_driver(&fast_gadget);
> + if (ret) {
> + printf("Add gadget failed\n");
> + return ret;
> + }
> +
> + udc_is_probbed = 1;
> + return 0;
> +}
> +
> +int fastboot_poll(void)
> +{
> + usb_gadget_handle_interrupts();
> +
> + if (gadget_is_connected)
> + return 0;
> + else
> + return 1;
> +}
> +
> +void fastboot_shutdown(void)
> +{
> + if (!udc_is_probbed)
> + return;
> + udc_is_probbed = 0;
> + usb_gadget_unregister_driver(&fast_gadget);
> +}
> +
> +int fastboot_tx_write(const char *buffer, unsigned int buffer_size)
> +{
> + int ret;
> +
> + if (req_in->complete == NULL)
> + req_in->complete = fastboot_complete_in;
> +
> + memcpy(req_in->buf, buffer, buffer_size);
> + req_in->length = buffer_size;
> + ret = usb_ep_queue(ep_in, req_in, 0);
> + if (ret)
> + printf("Error %d on queue\n", ret);
> + return 0;
> +}
> diff --git a/drivers/usb/gadget/g_fastboot.h
> b/drivers/usb/gadget/g_fastboot.h new file mode 100644
> index 0000000..733eb38
> --- /dev/null
> +++ b/drivers/usb/gadget/g_fastboot.h
> @@ -0,0 +1,15 @@
> +#ifndef _G_FASTBOOT_H_
> +#define _G_FASTBOOT_H_
> +
> +#define EP_BUFFER_SIZE 4096
> +
> +extern struct usb_ep *ep_in;
> +extern struct usb_request *req_in;
> +extern struct usb_ep *ep_out;
> +extern struct usb_request *req_out;
> +
> +void rx_handler_command(struct usb_ep *ep, struct usb_request *req);
> +int fastboot_tx_write(const char *buffer, unsigned int buffer_size);
> +const char *fb_find_usb_string(unsigned int id);
> +
> +#endif
> diff --git a/drivers/usb/gadget/u_fastboot.c
> b/drivers/usb/gadget/u_fastboot.c new file mode 100644
> index 0000000..76116c0
> --- /dev/null
> +++ b/drivers/usb/gadget/u_fastboot.c
> @@ -0,0 +1,260 @@
> +/*
> + * (C) Copyright 2008 - 2009
> + * Windriver, <www.windriver.com>
> + * Tom Rix <Tom.Rix@windriver.com>
> + *
> + * Copyright 2011 Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> + *
> + * SPDX-License-Identifier: GPL-2.0+
> + */
> +/*
> + * Part of the rx_handler were copied from the Android project.
> + * Specifically rx command parsing in the usb_rx_cmd_complete
> + * function of the file
> bootable/bootloader/legacy/usbloader/usbloader.c
> + *
> + * Repository:
> https://android.googlesource.com/platform/bootable/bootloader/legacy
> + * Files: usbloader/usbloader.c
> + * Commit: 4205b865141ff2e255fe1d3bd16de18e217ef06a
> + *
> + * Copyright (C) 2008 The Android Open Source Project
> + *
> + * SPDX-License-Identifier: BSD-2-Clause
> + */
> +#include <common.h>
> +#include <usb/fastboot.h>
> +#include <linux/usb/ch9.h>
> +#include <linux/usb/gadget.h>
> +#include "g_fastboot.h"
> +
> +#define FASTBOOT_VERSION "0.4"
> +
> +/* The 64 defined bytes plus \0 */
> +#define RESPONSE_LEN (64 + 1)
> +
> +static unsigned int download_size;
> +static unsigned int download_bytes;
> +
> +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)
> +{
> + req_in->complete = compl_do_reset;
> + fastboot_tx_write_str("OKAY");
> +}
> +
> +static int strcmp_l1(const char *s1, const char *s2)
> +{
> + 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("downloadsize", cmd)) {
> + char str_num[12];
> +
> + sprintf(str_num, "%08lx", load_size);
> + strncat(response, str_num, sizeof(response));
> + } else if (!strcmp_l1("product", cmd)) {
> + s = fb_find_usb_string(FB_STR_PRODUCT_IDX);
> + if (s)
> + strncat(response, s, sizeof(response));
> + else
> + strcpy(response, "FAILValue not set");
> + } else if (!strcmp_l1("serialno", cmd)) {
> + s = fb_find_usb_string(FB_STR_SERIAL_IDX);
> + if (s)
> + strncat(response, s, sizeof(response));
> + else
> + strcpy(response, "FAILValue not set");
> + } else if (!strcmp_l1("cpurev", cmd)) {
> + s = fb_find_usb_string(FB_STR_PROC_REV_IDX);
> + if (s)
> + strncat(response, s, sizeof(response));
> + else
> + strcpy(response, "FAILValue not set");
> + } else if (!strcmp_l1("secure", cmd)) {
> + s = fb_find_usb_string(FB_STR_PROC_TYPE_IDX);
> + 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 32768
> +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 *)load_addr + download_bytes, buffer,
> transfer_size); +
> + download_bytes += transfer_size;

The dfu backend uses zero copy approach.

> +
> + /* 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 (download_bytes && !(download_bytes % BYTES_PER_DOT)) {
> + printf(".");
> + if (!(download_bytes % (74 * BYTES_PER_DOT)))
> + printf("\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 > load_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();
> + }
> + fastboot_tx_write_str(response);
> +}
> +
> +static char boot_addr_start[32];
> +static char *bootm_args[] = { "bootm", boot_addr_start, NULL };
> +
> +static void do_bootm_on_complete(struct usb_ep *ep, struct
> usb_request *req) +{
> + req->complete = NULL;
> + fastboot_shutdown();
> + printf("Booting kernel..\n");

puts();

> +
> + 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)
> +{
> + sprintf(boot_addr_start, "0x%lx", load_addr);
> +
> + req_in->complete = do_bootm_on_complete;
> + fastboot_tx_write_str("OKAY");
> + return;
> +}
> +
> +struct cmd_dispatch_info {
> + char *cmd;
> + void (*cb)(struct usb_ep *ep, struct usb_request *req);
> +};
> +
> +static 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,
> + },
> +};
> +
> +void rx_handler_command(struct usb_ep *ep, struct usb_request *req)
> +{
> + char response[RESPONSE_LEN];
> + char *cmdbuf = req->buf;
> + void (*func_cb)(struct usb_ep *ep, struct usb_request *req)
> = NULL;
> + int i;
> +
> + sprintf(response, "FAIL");
> +
> + 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);
> + }
> +}
> diff --git a/include/usb/fastboot.h b/include/usb/fastboot.h
> new file mode 100644
> index 0000000..b348886
> --- /dev/null
> +++ b/include/usb/fastboot.h
> @@ -0,0 +1,36 @@
> +/*
> + * (C) Copyright 2008 - 2009
> + * Windriver, <www.windriver.com>
> + * Tom Rix <Tom.Rix@windriver.com>
> + *
> + * Copyright 2011 Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> + *
> + * SPDX-License-Identifier: GPL-2.0+
> + */
> +
> +#ifndef FASTBOOT_H
> +#define FASTBOOT_H
> +
> +#include <common.h>
> +#include <command.h>
> +#include <linux/usb/ch9.h>
> +#include <linux/usb/gadget.h>
> +
> +#define FB_STR_PRODUCT_IDX 1
> +#define FB_STR_SERIAL_IDX 2
> +#define FB_STR_CONFIG_IDX 3
> +#define FB_STR_INTERFACE_IDX 4
> +#define FB_STR_MANUFACTURER_IDX 5
> +#define FB_STR_PROC_REV_IDX 6
> +#define FB_STR_PROC_TYPE_IDX 7
> +
> +#ifdef CONFIG_CMD_FASTBOOT
> +
> +int fastboot_init(void);
> +void fastboot_shutdown(void);
> +int fastboot_poll(void);
> +
> +int fastboot_board_init(struct usb_gadget_strings **str);
> +
> +#endif
> +#endif

To sum up:

It seems that you are using UDC driver + gadget approach for fastboot.

However, current gadgets for downloading data (DFU, UMS, THOR) use UDC +
composite gadget + function.

Also they use common download code - g_dnl.c to implement their
commands.

I would be more than happy if you were willing to port the fastboot
protocol to the existing framework.
For overall picture of the current design please look into the following
keynote:
http://www.denx.de/wiki/pub/U-Boot/MiniSummitELCE2013/dfu_elce_u-boot.pdf

Please let me know if you have any questions.

--
Best regards,

Lukasz Majewski

Samsung R&D Institute Poland (SRPOL) | Linux Platform Group