1 .. SPDX-License-Identifier: GPL-2.0+
9 The protocol that is used over USB and UDP is described in [1]_.
11 The current implementation supports the following standard commands:
16 - ``erase`` (if enabled)
17 - ``flash`` (if enabled)
20 - ``reboot-bootloader``
21 - ``set_active`` (only a stub implementation which always succeeds)
23 The following OEM commands are supported (if enabled):
25 - ``oem format`` - this executes ``gpt write mmc %x $partitions``
26 - ``oem partconf`` - this executes ``mmc partconf %x <arg> 0`` to configure eMMC
27 with <arg> = boot_ack boot_partition
28 - ``oem bootbus`` - this executes ``mmc bootbus %x %s`` to configure eMMC
30 Support for both eMMC and NAND devices is included.
35 The counterpart to this is the fastboot client which can be found in
36 Android's ``platform/system/core`` repository in the fastboot
37 folder. It runs on Windows, Linux and OSX. The fastboot client is
38 part of the Android SDK Platform-Tools and can be downloaded from [2]_.
46 The fastboot gadget relies on the USB download gadget, so the following
47 options must be configured:
51 CONFIG_USB_GADGET_DOWNLOAD
52 CONFIG_USB_GADGET_VENDOR_NUM
53 CONFIG_USB_GADGET_PRODUCT_NUM
54 CONFIG_USB_GADGET_MANUFACTURER
56 NOTE: The ``CONFIG_USB_GADGET_VENDOR_NUM`` must be one of the numbers
57 supported by the fastboot client. The list of vendor IDs supported can
58 be found in the fastboot client source code.
63 The fastboot protocol requires a large memory buffer for
64 downloads. This buffer should be as large as possible for a
65 platform. The location of the buffer and size are set with
66 ``CONFIG_FASTBOOT_BUF_ADDR`` and ``CONFIG_FASTBOOT_BUF_SIZE``. These
67 may be overridden on the fastboot command line using ``-l`` and
70 Fastboot environment variables
71 ------------------------------
76 Fastboot partition aliases can also be defined for devices where GPT
77 limitations prevent user-friendly partition names such as ``boot``, ``system``
78 and ``cache``. Or, where the actual partition name doesn't match a standard
79 partition name used commonly with fastboot.
81 The current implementation checks aliases when accessing partitions by
82 name (flash_write and erase functions). To define a partition alias
83 add an environment variable similar to::
85 fastboot_partition_alias_<alias partition name>=<actual partition name>
89 fastboot_partition_alias_boot=LNX
91 Raw partition descriptors
92 ^^^^^^^^^^^^^^^^^^^^^^^^^
94 In cases where no partition table is present, a raw partition descriptor can be
95 defined, specifying the offset, size, and optionally the MMC hardware partition
96 number for a given partition name.
98 This is useful when using fastboot to flash files (e.g. SPL or U-Boot) to a
99 specific offset in the eMMC boot partition, without having to update the entire
102 To define a raw partition descriptor, add an environment variable similar to::
104 fastboot_raw_partition_<raw partition name>=<offset> <size> [mmcpart <num>]
108 fastboot_raw_partition_boot=0x100 0x1f00 mmcpart 1
113 Variables retrived through ``getvar`` can be overridden by defining
114 environment variables of the form ``fastboot.<variable>``. These are
115 looked up first so can be used to override values which would
116 otherwise be returned. Using this mechanism you can also return types
117 for NAND filesystems, as the fully parameterised variable is looked
120 fastboot.partition-type:boot=jffs2
125 When executing the fastboot ``boot`` command, if ``fastboot_bootcmd`` is set
126 then that will be executed in place of ``bootm <CONFIG_FASTBOOT_BUF_ADDR>``.
131 The Fastboot implementation in U-Boot allows to write images into disk
132 partitions. Target partitions are referred on the host computer by
135 For GPT/EFI the respective partition name is used.
137 For MBR the partitions are referred by generic names according to the
140 <device type><device index letter><partition index>
142 Example: ``hda3``, ``sdb1``, ``usbda1``.
144 The device type is as follows:
146 * IDE, ATAPI and SATA disks: ``hd``
148 * USB media: ``usbd``
149 * MMC and SD cards: ``mmcsd``
150 * Disk on chip: ``docd``
153 The device index starts from ``a`` and refers to the interface (e.g. USB
154 controller, SD/MMC controller) or disk index. The partition index starts
155 from ``1`` and describes the partition number on the particular device.
157 Writing Partition Table
158 -----------------------
160 Fastboot also allows to write the partition table to the media. This can be
161 done by writing the respective partition table image to a special target
162 "gpt" or "mbr". These names can be customized by defining the following
163 configuration options:
167 CONFIG_FASTBOOT_GPT_NAME
168 CONFIG_FASTBOOT_MBR_NAME
173 Enter into fastboot by executing the fastboot command in U-Boot for either USB::
180 link up on port 0, speed 100, full duplex
181 Using ethernet@4a100000 device
182 Listening for fastboot command on 192.168.0.102
184 On the client side you can fetch the bootloader version for instance::
186 $ fastboot getvar version-bootloader
187 version-bootloader: U-Boot 2019.07-rc4-00240-g00c9f2a2ec
188 Finished. Total time: 0.005s
190 or initiate a reboot::
194 and once the client comes back, the board should reset.
196 You can also specify a kernel image to boot. You have to either specify
197 the an image in Android format *or* pass a binary kernel and let the
198 fastboot client wrap the Android suite around it. On OMAP for instance you
199 take zImage kernel and pass it to the fastboot client::
201 $ fastboot -b 0x80000000 -c "console=ttyO2 earlyprintk root=/dev/ram0 mem=128M" boot zImage
202 creating boot image...
203 creating boot image - 1847296 bytes
204 downloading 'boot.img'...
208 finished. total time: 2.766s
210 and on the U-Boot side you should see::
212 Starting download of 1847296 bytes
213 ........................................................
214 downloading of 1847296 bytes finished
216 ## Booting Android Image at 0x81000000 ...
217 Kernel load addr 0x80008000 size 1801 KiB
218 Kernel command line: console=ttyO2 earlyprintk root=/dev/ram0 mem=128M
219 Loading Kernel Image ... OK
227 .. [1] :doc:`fastboot-protocol`
228 .. [2] https://developer.android.com/studio/releases/platform-tools