--- /dev/null
+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.
projects / karo-tx-uboot.git / blobdiff