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author | Tom Rini <trini@ti.com> | 2014-05-22 12:56:15 -0400 |
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committer | Tom Rini <trini@ti.com> | 2014-05-22 12:56:15 -0400 |
commit | c9afa7cea84c9b7346fcd2710577bcc386631aba (patch) | |
tree | 6b167eb7bd0ab10fff37259467e07feba24ba843 /doc | |
parent | d7782d06534fe4fa47a49fa7c106de5ba85a9687 (diff) | |
parent | fc25fa27e5f439705e9ca42182014e2d75d9f0ae (diff) | |
download | u-boot-c9afa7cea84c9b7346fcd2710577bcc386631aba.zip u-boot-c9afa7cea84c9b7346fcd2710577bcc386631aba.tar.gz u-boot-c9afa7cea84c9b7346fcd2710577bcc386631aba.tar.bz2 |
Merge branch 'master' of git://git.denx.de/u-boot-usb
Diffstat (limited to 'doc')
-rw-r--r-- | doc/README.android-fastboot | 91 | ||||
-rw-r--r-- | doc/README.android-fastboot-protocol | 170 |
2 files changed, 261 insertions, 0 deletions
diff --git a/doc/README.android-fastboot b/doc/README.android-fastboot new file mode 100644 index 0000000..f1d128c --- /dev/null +++ b/doc/README.android-fastboot @@ -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 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. + + + +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. |