mirror of
https://github.com/smaeul/u-boot.git
synced 2025-11-03 21:48:15 +00:00
586a1bf5b2
Convert Android documentation from regular txt format to Sphinx (RST).
Also add Android index.rst file and reference it in root index.rst, so
that Android documentation is visible.
Test:
$ make htmldocs
$ xdg-open doc/output/index.html
Signed-off-by: Sam Protsenko <joe.skb7@gmail.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
207 lines
5.8 KiB
ReStructuredText
207 lines
5.8 KiB
ReStructuredText
.. SPDX-License-Identifier: GPL-2.0+
|
|
|
|
Android Fastboot
|
|
================
|
|
|
|
Overview
|
|
--------
|
|
|
|
The protocol that is used over USB and UDP is described in [1]_.
|
|
|
|
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 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 [2]_.
|
|
|
|
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
|
|
|
|
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.
|
|
|
|
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``. 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.
|
|
|
|
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. 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>
|
|
|
|
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``
|
|
|
|
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.
|
|
|
|
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
|
|
|
|
In Action
|
|
---------
|
|
|
|
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 version-bootloader
|
|
version-bootloader: U-Boot 2019.07-rc4-00240-g00c9f2a2ec
|
|
Finished. Total time: 0.005s
|
|
|
|
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 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 ...
|
|
|
|
References
|
|
----------
|
|
|
|
.. [1] :doc:`fastboot-protocol`
|
|
.. [2] https://developer.android.com/studio/releases/platform-tools
|