Problem
I'm looking for a way to flash an ESP32 module's memory without installing the whole IDF software suite.
Why
Because I want to integrate ESP32 onto a custom board along with a low-performance ARM-powered CPU which runs a tiny Linux distro (based on Debian), and I want to flash ESP32 from this tiny Linux distro.
I know I could use the bootloader, but who will upload the initial bootloader? I don't want to do extra steps, so my idea is to embed the ESP32 module onto my custom board, and let the Linux to flash it from factory-state (when it's flash is empty, ie. no preloaded bootloader). Or is the serial bootloader always preinstalled on all ESP32 modules (like on ESP-WROOM-32)?
Why I don't want to use IDF? Because I don't want to build or debug anything, I just want to flash myprogram.bin onto ESP32. Also, as the board is low-performance, it would take ages to download everything for running IDF.
Current state
The ESP32 module is now visible via UART (RX,TX,GND), and if I held low the GPIO0, it runs the bootloader (my current module is embedded onto a NodeMCU - but there is no USB connected, this is raw UART!):
rst:0x1 (POWERON_RESET),boot:0x3 (DOWNLOAD_BOOT(UART0/UART1/SDIO_REI_REO_V2))
waiting for download
Could I expect the same behavior (controlling GPIO0 for running the bootloader) for all ESP32 modules, or this works just because guys at NodeMCU preprogrammed already some bootloader onto it?
I'm looking for a way to flash this ESP32 preferrably without any python script.
The ESP32 has a first-stage bootloader in ROM capable of writing to Flash - that's what's printing your output. You can talk to it if you know the protocol - this is implemented by the Python scripts in ESP IDF. If you don't want to use the official implementation because it's too heavy, you'll have to write your own implementation of this protocol which scratches your specific itch. Fortunately it's more or less documented and you can likely reverse engineer any missing knowledge from official Python scripts.
Actually Espressif also provides a nice and small binary for flashing ESPs:
https://github.com/espressif/esp-serial-flasher
Serial flasher component provides portable library for flashing Espressif SoCs (ESP32, ESP32-S2, ESP8266) from other host microcontroller. Espressif SoCs are normally programmed via serial interface (UART). Port layer for given host microcontroller has to be implemented, if not available.
One more (but very important) addition:
You have to modify this repo to make it work correctly, and also you might have to upload not just your binary, but also bootloader and partition_table.
Related
I have a custom ESP32-S2-based circuit board with USB-C which does not have a USB-serial converter IC like a common dev board might. On this board, USB(-) is on GPIO19, and USB(+) is on GPIO20. USB works great for powering the board and for uploading firmware.
The board works well and I have access to good old-fashioned serial console via a USB-to-logic level serial interface, but it would be nice to be able to get serial out to USB along with the firmware upload (like a dev board).
I’m using PlatformIO in Visual Studio Code, and writing with arduino-esp32 rather than ESP-IDF.
I understand by these instructions from Espressif that when using ESP-IDF I can configure log output to go to USB CDC rather than UART, and this has been done successfully on my custom board. But I would like to be able to do this without having to switch over to ESP-IDF.
I’m presuming that one of the partitions that PlatformIO is building for me is this configuration with some nice common sense defaults, but I can’t see how I might alter those defaults to do what I’m looking for.
Any thoughts or pointers?
I'm new with NodeMCU firmware use. I have a Amica ESP-12E (v2?) dev kit connected to a DHT22 which I program using the Arduino IDE. All is setup and working fine.
My problem came when I wanted to update NodeMCU firmware. Since I don't really know what came pre installed from China, I downloaded ESPlorer to try to determine NodeMCU version. I get the following "error" when I reset the dev board:
Communication with MCU..Got answer! Communication with MCU established.
AutoDetect firmware...
Can't autodetect firmware, because proper answer not received (may be unknown firmware).
Please, reset module or continue.
{{a long string of weird characters that I can't copy and paste appear here}}
At this point I'm totally clueless about what version of firmware I have. Is there a way to obtain NodeMCU firmware version by software via Arduino IDE code, ESPlorer GUI or something similar?
On the other hand, is there a really easy way to compile/download latest NodeMCU firmware BIN file? Even one with all the modules active will be fine for me now, I'm just trying to understand and test things.
You seem to be confusing two very different platforms. I leave out some details as not to confuse you any further.
Arduino: you use Arduino programming in the Arduino IDE then build and install a binary to your device whenever the application changes. No NodeMCU firmware needed!
NodeMCU: you flash the NodeMCU firmware once (e.g. using esptool.py) and then upload Lua code (e.g. using ESPlorer) whenever the application changes. This is more lightweight than the Arduino platform.
On the other hand, is there a really easy way to compile/download
latest NodeMCU firmware BIN file?
Yes, have a look at the NodeMCU documentation at http://nodemcu.readthedocs.io/en/latest/en/build/. The easiest is to use the cloud builder at https://nodemcu-build.com/. I currently suggest to build from the dev branch because flashing is easier with it.
As pointed out you have several options for firmware and you'll need to make a choice as to which suits you going forward. If you are going to stick with the Nodemcu LUA firmware you can determine the version by typing:
print(node.info())
at the command line prompt.
There are alternatives to using ESPlorer e.g. Putty or Coolterm that will give you the raw output from the device with no interpretation. So if you have the correct serial port settings and the device plugged into the USB port it will show the banner when you reset giving an indication of the origin and version of the installed firmware.
In ESPlorer, there is an option under settings which if unchecked will stop looking checking for the version of the code.
For whatever reason, ESPlorer is not designed to read nodemcu version.
The error message throws you off, could lead you to think, there is an error.
At best, the above error can be ignored. It has no impact at all. In background, init.lua is up and running.
I'm having a bit of a hard time fully understanding how the kernel starts in linux. I'm a wince developer and our company decided to run with linux instead now.
We outsourced all of the board bringup and the package I recieved is quit a bit different for the prototype board we have compared to the nitrogen6x we have been using.
Before i start listing the differences for the distro we created, the kernels are identical. The distro we have been using is a busybox system. The one we recieved from the vendor is sysvinit. I removed mdev from busybox and we are only using udev.
when I use the kernel on our busybox build the touch screen drivers breaks, or doesn' run, or does something totally magical. I'm not quit sure... there is a /dev/input/event0 device which when run on the sysvinit side is a touch device.. Is the kernel not the mechanism that binds the built-in drivers to a device node? I thought udev was for more dynamic events in the system.
On the other hand I can't really tell whats been loaded on my device. Is there a way to list running drivers that were built into the kernel? my touch pad is up? This is a fairly simple process of looking at the registry on wince to see which devices were loaded.
I guess what I'm really trying to discover, isn't so much how to add a driver to the kernel, its how the whole thing gets is plumbed together. I've found plenty of documents on createing kernel modules, but i haven't found a good resource on how to pull everything together from scratch so you can actually use said modules. Going back to the example of the touchscreen driver, its built into the kernel, how does that get plugged into /dev/input/event0??
I'm kind of having a difficult time finding good resources mostly because searching google for varations of linux/drivers/device nodes/ piles in tons of random crap from everywhere.
What you probably want to use now is evtest. It will allow you to know what are the input devices that are present and ready to use on your system.
To get more information on the input subsystem and more generic information on how the kernel is working, I can direct you to our training materials. The materials are free to download, use and redistribute.
The general answer is, there is no single, easy place to look to discover what drivers have been loaded by the kernel if they are compiled in. Of course, lsmod will display any drivers that were dynamically loaded after kernel boot.
The kernel does not create device nodes. That is, to quote your question, the kernel does not "bind" the driver to the device node. The association between kernel driver and device node is contained in the major and minor numbers registered when the driver is initialized. You can have a device node on your file system for which there is no corresponding driver (common especially in older devices where device nodes were statically created on the file system) and you can also have a driver installed for which there is no device node.
Modern Linux distros have dynamically created device nodes created on a mount point called /dev and this is usually a tmpfs file system, meaning it is volatile - it gets destroyed on every boot and recreated dynamically on each new boot.
udev is the magic that creates most device nodes based on events that it receives from the kernel when a new device is discovered (this can be after boot on device plugin, like a USB disk) or on startup when udev reads the queued events and acts on them. As you noted, busybox has a limited udev implementation called mdev.
Study udev and you will get a much better understanding of the process. Hope this helps a little.
I need to set up USB communication between a Windows 7 host and a Linux device for data transfer. I was able to compile the Linux kernel on the device to include the Gadget Zero driver in the kernel (not as a loadable module - Linux version 3.0.15). My project has some requirements, which also explains why I chose Gadget Zero:
1) On the Windows 7 host, a kernel mode driver must be used to communicate over the USB connection for sending and receiving bulk data. (speed is not important, not a lot of data at once).
2) On the linux device, no requirements on USB side except send and receive data easily over USB link. The data received will eventually be "unmarshalled" to call functions in another kernel module (and those responses packaged and sent back to the host).
3) Multiple linux devices will be connected to the host, so need easy way to enumerate connected devices and communicate with them.
So due to the requirements, I decided against the Gadget Serial. I'm having serious issues sending and receiving data over the virtual COM port in kernel mode (KMDF) in Win 7 host. WinUSB does not seem to want to open my attached device (I'm using KMDF windows USB driver from template in VS2012) Also, the gadget serial driver on the linux side, I cannot find the functions where the data is received and sent. Plus, any received data on the linux device seems to be echoed back to the host for some reason. (and to test this, I wrote a simple user-mode app in Windows, which is a no-no for my project).
Gadget Zero, it appears much simpler on the linux side. I can plug the USB cable to the Win7 host, and I can get the device to appear in the device manager. However, again I am having problems with getting communication going over the link. Gadget Zero has 2 bulk endpoints, so this shouldn't be an issue. Surely, someone has made data communication possible between a Windows host and a linux device using Gadget Zero? With Gadget Zero, it should be easy to enumerate the connected linux devices and communicate with them.
The trick is to keep the Windows side communication in kernel mode. Can someone point me in the right direction perhaps with Gadget Zero, Windows 7 KMDF, and some sample source code? I have a hard time believing no one has done this before because my internet searches don't turn up much. (and mostly user-mode solutions with Gadget Serial).
Thanks!
So you're writing a Win32 driver in which you want to communicate with your linuxed usb? I haven't written much win32 kernel code, but I believe I've seen a huge section in the doc, saying something like "This is how you make usb drivers"... That'd be it. In other words, when in kernel mode you have access to the full kernel usb layer. You don't need an existing driver or whatnot.
On the linux side you can use the serial gadget, in a different run mode. Only the default run mode, registers it self as VCP. There exist a more basic mode:
modprobe g_serial use_acm=0
Give it your own vendor id and you'll be able to attach your very own custom win32 driver. The 'multiple linux devices' will be handled by Windows. (Multiple instances of your driver, will be initiated.)
The echo you're seeing btw, is most likely a terminal feature. (The terminal mode on uarts will echo.) You have to disable it, when connecting. And now that you're at it, you also have to disable the xon/xoff, esc chars etc. (Standard legacy rubbish.)
And another thing. I'm not sure the gadget zero actually sends the data onto the line. It's meant for testing the gadget framework. (I could be mistaken though.)
Anyway, you've prolly solved this issue years ago. I'd be nice to know what you came up with.
I am new to android and wish to play around with the emulator.
What I want to do is to create my own piece of virtual hardware that can collect OpenGL commands and produce OpenGL graphics.
I have been told that in order to do this I will need to write a linux kernal driver to enable communication with the hardware. Additionally, I will need to write an Android user space library to call the kernal driver.
To start with I plan on making a very simple piece of hardware that only does, say 1 or 2, commands.
Has anyone here done something like this? If so, do you have any tips or possible links to extra information?
Any feedback would be appreciated.
Writing a hardware emulation is a tricky task and by no means easy. So if you really want to do this, I'd not start from scratch. In your case I'd first start with some simpler (because many of the libraries are already in place on guest and the host side): Implementing a OpenGL passthrough for ordinary Linux through qemu. What does it take:
First you add some virtual GPU into qemu, which also involves adding a new graphics output module that uses OpenGL (so far qemu uses SDL). Next you create DRI/DRM drivers in the Linux kernel, that will run on the guest (Android uses its own graphics system, but for learning DRI/DRM are fine), as well as in Mesa. On the host side you must translate what comes from qemu in OpenGL calls. Since the host side GPU is doing all the hard work your DRI/DRM part will be quite minimal and just build a brigde.
The emulator that comes with Android SDK 23 already runs OpenGL, you can try this out with the official MoreTeapots example: https://github.com/googlesamples/android-ndk/tree/a5fdebebdb27ea29cb8a96e08e1ed8c796fa52db/MoreTeapots
I am pretty sure that it is hardware accelerated, since all those polygons are rendering at 60 FPS.
The AVD creation GUI from Studio has a hardware acceleration option, which should control options like:
==> config.ini <==
hw.gpu.enabled=yes
hw.gpu.mode=auto
==> hardware-qemu.ini <==
hw.gpu.enabled = true
hw.gpu.mode = host
hw.gpu.blacklisted = no
in ~/.android/avd/Nexus_One_API_24.a/.