All these examples assume linux host. Personnally I use very stripped down Debian (Jessie), but acknowledging most of the rest of world goes with (bloaded...) Ubuntus, these instructions should work just fine in there too. Ubuntu is practically a Debian testing/unstable, ie. equipped with newer software versions.
There might be already usable packages in distribution's package repositories. I think for example esptool is packaged. You can use them if they exists, but at least these tar.gz's below contain all necessary components.
Also, these tar.gz's dont make you install any rarely needed packages. Personnally I hate instructions where you are instructed to install this and that, cut-pasting stuff that you are bit worried of what it actually dows. These instuctions below are meant to be simple and readable so that you know what is done to your system and know how to get rid of all changes made.
Download SDK and toolchain packages from links below. These are compiled for use in 64bit systems.
To refer original sources :
SDK package is unmodified, except modification of getting rid of annoying compiler warning with fix explained at http://bbs.espressif.com/viewtopic.php?t=1428.
Extract downloaded packages with commands below. Since all files in packages are prefixed with /usr/local, option -C / chdirs tar into root before extracting.
esp:~/Downloads$ sudo tar -C / -xzf esp-open-sdk-v1.5.4_160520.tar.gz esp:~/Downloads$ sudo tar -C / -xzf esp-toolchain-20170304.tar.gz
After extraction there will be new filesystem items :
/usr/local/esptool /usr/local/xtensa-lx106-elf /usr/local/bin/use-esp8266-build-system /usr/local/ESP8266_NONOS_SDK /usr/local/ESP8266_NONOS_SDK_V1.5.4_16_05_20
Directory contains the SDK, ie. required libraries and headers to link complete working esp8266 image.
Symlink to SDK directory to make easier to keep multiple SDK versions available. Makefiles and wrappers should utilize includes and libs through symlink so that so that changing and reverting back to differens SDK versions require only change on symlink's destination. Not changes to sources itself.
...probably you are already familiar with concept of symlinks.
esptool is for flashing the compiled esp-image-0x40000.bin into esp8266 chip. Esptool might be already packaged with your system, but at least this works. esptool requires python-serial package and access to system's serial devices. This will be explained later.
Contains cross compiler for compiling the esp binaries.
Small shell helper snippet to set environment variables to include cross compiled and required library and include paths into environment. Basic usage is, in terminal you are using invoke command as :
esp:~$ . use-esp8266-build-system
Don't forget the dot in front. It means that it's run directly on current shell so that environment variables are included into it. Snippet itself is simple, stupid and safe :
esp:~$ cat /usr/local/bin/use-esp8266-build-system
#!/bin/bash
PATH="/usr/local/xtensa-lx106-elf/bin:/usr/local/esptool:$PATH";
export PATH
ESPTOOL_PORT="/dev/ttyUSB0"
export ESPTOOL_PORT
# These are defined in Makefile, probably there is no
# use of invoking xtensa-gcc directly
if [ "$1" == "--standalone" ]; then
CFLAGS="-I/usr/local/ESP8266_NONOS_SDK/include"
LDFLAGS="-L/usr/local/ESP8266_NONOS_SDK/ld -L/usr/local/ESP8266_NONOS_SDK/lib"
export CFLAGS
export LDFLAGS
fi
To get rid of actions above, just remove created directories and your system is back on state you started.
Late warning. Never!! untar with method above without either validating the package contents beforehand or fully trusting the source. You don't probably want your /etc/passwd or /sbin/init overwritten by "accident". Always check before package extraction, what really will get done.
Serial communication is needed for interacting and flashing the esp8266 chip. Below is explained required changes to system so that future development and flashing can be done without sudoing or running anything extra as root.
The weirdness with esp8266 is that it strictly uses CRLF line terminations in serial communication in both directions. Common terminal emulators like putty or minicom does not work since they support only LF line-endings at least on not both directions. Of course you can emulate CR with Ctrl+M but it's far from perfect solution for long run.
Personal preference is cutecom which is packaged at least in Wheezy and successors. Most probably exists also on Ubuntus. There might be also more alternatives, but since cutecom did exactly what was needed, I didn't search for more.
As you must have already read from net, you cannot use direct serial RS-232 connection but you need something called USB to TTL level converter. Adjacent link points to cable I use, fully supported by Linux for very long time.
In case you compile you own very very stripped down kernels into your very very streamlined system like I do, required module for cable above is :
Device Drivers --->
[*] USB support --->
<M> USB Serial Converter support --->
<M> USB CP210x family of UART Bridge Controllers
...with USB id...
Bus 003 Device 005: ID 10c4:ea60 Cygnal Integrated Products, Inc. CP210x UART Bridge / myAVR mySmartUSB light
But since you are running distribution kernel, you don't need to worry about that above.
To operate serial device without root access, you need to grant yourself into system group that allows access to serial devices. On Debians and Ubuntus (probably almost everywhere) the required group is dialout.
Add youself to group by command : (or edit /etc/group with care..)
esp:~$ sudo adduser youraccount dialout
Remember that you need to logout and log back in to get chat new group membership active. After successful relogin you should have the dialout group active on your group memberships :
esp:~$ id -a
To exit group, reverse command is :
esp:~$ sudo deluser youraccount dialout
esptool.py requires python-serial. On Debian based system install it with :
pri:~$ sudo apt-get install python-serial
Again, to get rid of installation :
pri:~$ sudo apt-get --purge remove python-serial pri:~$ sudo apt-get --purge autoremove
As a result of previous steps you should have :
# TTL-USB-device is writable for dialout group
esp:~$ ls -l /dev/ttyUSB*
crw-rw---- 1 root dialout 188, 0 maali 4 14:11 /dev/ttyUSB0
# you belong to that dialout group
esp:~$ id -a
uid=1002(tempuser) gid=1002(tempuser) groups=1006(tempuser),4(adm),8(mail),20(dialout), (...snip...)
# shell-snippet updates the path (remember dot..)
esp:~$ . use-esp8266-build-system
esp:~$ set | fgrep PATH
PATH=/usr/local/xtensa-lx106-elf/bin:/usr/local/esptool:/usr/local/bin:/usr/bin:/bin
# cross-compiler works
esp:~$ xtensa-lx106-elf-gcc -v
Using built-in specs.
COLLECT_GCC=xtensa-lx106-elf-gcc
COLLECT_LTO_WRAPPER=/usr/local/xtensa-lx106-elf/bin/../libexec/gcc/xtensa-lx106-elf/4.8.5/lto-wrapper
Target: xtensa-lx106-elf
Configured with: /home/tempuser/esp-open-sdk/crosstool-NG/. (...snip...)
Thread model: single
gcc version 4.8.5 (crosstool-NG crosstool-ng-1.22.0-55-gecfc19a)
# esptool.py works
esp:~$ esptool.py -h
usage: esptool [-h] [--port PORT] [--baud BAUD]
{load_ram,dump_mem,
...(snip)...
esptool.py v1.2-dev - ESP8266 ROM Bootloader Utility
positional arguments:
{load_ram,dump_mem,read_mem,
...(snip)...
optional arguments:
-h, --help show this help message and exit
--port PORT, -p PORT Serial port device
--baud BAUD, -b BAUD Serial port baud rate used when flashing/reading