+================
Android Fastboot
-~~~~~~~~~~~~~~~~
+================
Overview
========
-The protocol that is used over USB is described in
-README.android-fastboot-protocol in same directory.
-The current implementation is a minimal support of the erase command,the
-"oem format" command and flash command;it only supports eMMC devices.
+The protocol that is used over USB and UDP is described in the
+``README.android-fastboot-protocol`` file in the same directory.
+
+The current implementation supports the following standard commands:
+
+- ``boot``
+- ``continue``
+- ``download``
+- ``erase`` (if enabled)
+- ``flash`` (if enabled)
+- ``getvar``
+- ``reboot``
+- ``reboot-bootloader``
+- ``set_active`` (only a stub implementation which always succeeds)
+
+The following OEM commands are supported (if enabled):
+
+- oem format - this executes ``gpt write mmc %x $partitions``
+
+Support for both eMMC and NAND devices is included.
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.
+
+The counterpart to this 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 OSX. The fastboot client is
+part of the Android SDK Platform-Tools and can be downloaded from:
+
+https://developer.android.com/studio/releases/platform-tools
Board specific
==============
+
+USB configuration
+-----------------
+
The fastboot gadget relies on the USB download gadget, so the following
options must be configured:
-CONFIG_USB_GADGET_DOWNLOAD
-CONFIG_USB_GADGET_VENDOR_NUM
-CONFIG_USB_GADGET_PRODUCT_NUM
-CONFIG_USB_GADGET_MANUFACTURER
+::
+
+ CONFIG_USB_GADGET_DOWNLOAD
+ CONFIG_USB_GADGET_VENDOR_NUM
+ CONFIG_USB_GADGET_PRODUCT_NUM
+ CONFIG_USB_GADGET_MANUFACTURER
-NOTE: The CONFIG_USB_GADGET_VENDOR_NUM must be one of the numbers supported by
-the fastboot client. The list of vendor IDs supported can be found in the
-fastboot client source code (fastboot.c) mentioned above.
+NOTE: The ``CONFIG_USB_GADGET_VENDOR_NUM`` must be one of the numbers
+supported by the fastboot client. The list of vendor IDs supported can
+be found in the fastboot client source code.
-The fastboot function is enabled by defining CONFIG_USB_FUNCTION_FASTBOOT,
-CONFIG_CMD_FASTBOOT and CONFIG_ANDROID_BOOT_IMAGE.
+General configuration
+---------------------
-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_FASTBOOT_BUF_ADDR and
-CONFIG_FASTBOOT_BUF_SIZE.
+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_FASTBOOT_BUF_ADDR`` and ``CONFIG_FASTBOOT_BUF_SIZE``. These
+may be overridden on the fastboot command line using ``-l`` and
+``-s``.
+
+Fastboot environment variables
+==============================
+
+Partition aliases
+-----------------
Fastboot partition aliases can also be defined for devices where GPT
limitations prevent user-friendly partition names such as "boot", "system"
and "cache". Or, where the actual partition name doesn't match a standard
-partition name used commonly with fastboot. Current implentation checks
-aliases when accessing partitions by name (flash_write and erase functions).
-To define a partition alias add an environment variable similar to:
-fastboot_partition_alias_<alias partition name>=<actual partition name>
-Example: fastboot_partition_alias_boot=LNX
+partition name used commonly with fastboot.
+
+The current implementation checks aliases when accessing partitions by
+name (flash_write and erase functions). To define a partition alias
+add an environment variable similar to:
+
+``fastboot_partition_alias_<alias partition name>=<actual partition name>``
+
+for example:
+
+``fastboot_partition_alias_boot=LNX``
+
+Variable overrides
+------------------
+
+Variables retrived through ``getvar`` can be overridden by defining
+environment variables of the form ``fastboot.<variable>``. These are
+looked up first so can be used to override values which would
+otherwise be returned. Using this mechanism you can also return types
+for NAND filesystems, as the fully parameterised variable is looked
+up, e.g.
+
+``fastboot.partition-type:boot=jffs2``
+
+Boot command
+------------
+
+When executing the fastboot ``boot`` command, if ``fastboot_bootcmd`` is set then
+that will be executed in place of ``bootm <CONFIG_FASTBOOT_BUF_ADDR>``.
Partition Names
===============
-The Fastboot implementation in U-boot allows to write images into disk
-partitions (currently on eMMC). Target partitions are referred on the host
-computer by their names.
+
+The Fastboot implementation in U-Boot allows to write images into disk
+partitions. Target partitions are referred on the host computer by
+their names.
For GPT/EFI the respective partition name is used.
For MBR the partitions are referred by generic names according to the
following schema:
- <device type>
<device index letter> <partition index>
+ <device type>
<device index letter><partition index>
-Example: hda3, sdb1, usbda1
+Example: ``hda3``, ``sdb1``, ``usbda1``
The device type is as follows:
- * IDE, ATAPI and SATA disks: hd
- * SCSI disks: sd
- * USB media: usbd
- * MMC and SD cards: mmcsd
- * Disk on chip: docd
- * other: xx
+ * IDE, ATAPI and SATA disks: ``hd``
+ * SCSI disks: ``sd``
+ * USB media: ``usbd``
+ * MMC and SD cards: ``mmcsd``
+ * Disk on chip: ``docd``
+ * other: ``xx``
-The device index starts from 'a' and refers to the interface (e.g. USB
+The device index starts from ``a`` and refers to the interface (e.g. USB
controller, SD/MMC controller) or disk index. The partition index starts
-from 1 and describes the partition number on the particular device.
+from ``1`` and describes the partition number on the particular device.
Writing Partition Table
=======================
+
Fastboot also allows to write the partition table to the media. This can be
done by writing the respective partition table image to a special target
"gpt" or "mbr". These names can be customized by defining the following
configuration options:
-CONFIG_FASTBOOT_GPT_NAME
-CONFIG_FASTBOOT_MBR_NAME
+::
+
+ CONFIG_FASTBOOT_GPT_NAME
+ CONFIG_FASTBOOT_MBR_NAME
In Action
=========
-Enter into fastboot by executing the fastboot command in u-boot and you
-should see:
-|GADGET DRIVER: usb_dnl_fastboot
+
+Enter into fastboot by executing the fastboot command in U-Boot for either USB:
+
+::
+
+ => fastboot usb 0
+
+or UDP:
+
+::
+
+ => fastboot udp
+ link up on port 0, speed 100, full duplex
+ Using ethernet@4a100000 device
+ Listening for fastboot command on 192.168.0.102
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
+
+::
+
+ $ fastboot getvar bootloader-version
+ bootloader-version: U-Boot 2014.04-00005-gd24cabc
+ finished. total time: 0.000s
or initiate a reboot:
-|>fastboot 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
+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 ...
+::
+
+ $ 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 U-Boot 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 ...
projects / oweals / u-boot.git / commitdiff