esptool is a tool to allow the creation of firmware files suitable 
for the ESP8266 chip, and flashing those file to the chip.

esptool runs on Windows, Linux and Mac OS X.

It can read a code file in the ELF format that the compilers produce.
From there it is possible to extract various sections that are present
in these files, to either directly dump a section to a file or to
assemble a firmware file comprised of several segments.

While the codebase implements many functions, only a few are used
by the program currently. The program interprets the arguments
given on the commandline, and in the order they are given.

The following commands are currently available:

-eo <filename>          Opens an ELF object file, parses it and caches
                        some of the information found therein.
                        Only works if there is no ELF file currently
                        opened.

-d <section> <filename> Reads the given section from the ELF file
                        and makes a raw dump into the specified
                        file.

-ec                     Closes the currently opened ELF file

-bo <filename>          Prepares an firmware file in the format
                        that is understood by the ESP chip.
                        Only works if an ELF file is opened, and
                        if no firmware file is prepared yet.
                        The result of the operations done on there
                        firmware image are saved when the it
                        is finally closed.

-bs <section>           Reads the specified section from the ELF
                        file and appends it to the firmware image.
                        
-bc                     Closes the firmware image and saves the result
                        as file to disk.

-v                      Increase verbosity level of the tool
                        Add more v's to increase it more, e.g.
                        -vv, -vvv.

-q                      Disable most of the output.

-cp <device>            Select the serial port device to use for
                        communicating with the ESP.
                        Default is /dev/ttyUSB0 on Linux, 
                        COM1 on Windows, /dev/tty.usbserial on Mac OS X.

-cd <board>             Select the reset method to use for resetting
                        the board. Currently supported methods are:

        none            No DTR/RTS manipulation

        ck              RTS controls RESET or CH_PD, DTR controls GPIO0

        wifio           DTR controls GPIO0 via PNP transistor and RESET
                        via a capacitor

-cb <baudrate>          Select the baudrate to use, default is 115200

-ca <address>           Address in flash memory to upload the data to
                        This Address is interpreted as hexadecimal
                        Default is 0x00000000

-cf <filename>          Upload the file "filename" to flash memory

When creating firmware images, the tool will automatically set the
required addresses, size-fields, etc. according to what it finds
in the ELF file.

Upon -bo it will start out with an empty image where only
the main header is set accordingly. Sections appear in the
firmware image in the exact same order as the -bs commands
are executed.

Parameters are executed in the order they appear. That means
that if, for example, you want a different port or baudrate
for the flash-upload, those parameters must appear befor
the -cf parameter.