STM32 - ESP8266 download file - stm32

i'm using STM32 as my microprocessor along with I2C EEPROM for storage and ESP8266 for Wifi
How can i download an update binary for the bootloader to flash using ESP8266 although the firmware file will be larger than STM32 Ram so i can't load the file from the ESP8266 in one chunk ?

I suppose that you want to update the stm32 firmware.
In this case allow to upload a new binary for the stm32 to the web, store it in the esp8266 file system (it must be bigger than stm32 flash size).
After that, enable flash memory writing, set an small protocol for update stm32 from serial comm from esp8266 the file to stm32 flash.
Remember that all functions that are used to update the stm32 flash must be in RAM.
I'm doing a project for stm32f4 and esp8266 and I will do exactly this.
OPTION 2:
If your program binary size is under 50% of stm32 flash size, then use the above half of the stm32 flash memory to store the new program, after reset, check if there is something there, and if it is then update (this is what i'm doing actually in stm32, very secure method to update since only stm32 cpu is used for update and it is very fast).

I suppose that you have two firmwares on the STM32 flash. First one is boot loader and the second one is your application. Your boot loader gets new firmware over serial interface of the ESP8266; so you can use flow control pins to halt communication until you write the data into flash memory.

I use that combination, stm32 and esp32/esp8266, for now i have not used firmware upgrade from esp (my stm32 supports it but I have not needed it for now).
The easier way is to set a serial protocol between both cpus. I'm using half of the stm32 memory for code and half for updating. What I do actually is using the communication protocolo is copy the file to the upper half of the flash memory. After when i reset the code i check if there is a firmware ready to be updated, then I copy from top half of flash to bottom half.
With this system, you can check if all is ok and the update process with take few ms. After you have this system tested (using for example a PC) you can try to do it from your esp, but it is just as easy as repeat the process.
My tip about the esp8266 is to download the file to a spiffs. If you are not using spiffs, use it, create a drive a little bigger than your memory.. for example if your stm32 firmware binary is around 60kb, and your target cpu is 256, use around 160kb for it.
There is another way, it is download the html file in chunks and then send them to the top half of the cpu, it is not very complex. I would requests chunks with the same size of the block size of your comunnication process (in my case i'm using 256b or 512b, i dont remember at this moment).
Anyways if you have enough spiffs size download the file, update the stm32 cpu, delete the file and send a reboot.
Dont forget to add a crc for data transmision between stm32 and esp8266
Btw you dont need to download it to ram , since update is used rarely and you have limitations like number of times that you can update a flash memory, so, it is not a problem to save it to flash in the esp8266 neither the stm32
Best regards

Related

Options on programing STM32 with another microcontroller

I'm going to use STM32f103 as a main microcontroller and ESP8266 as a Wi-Fi module in my project. These 2 chips are in contact with each other via UART.
I have a server that contains the "version2.bin" file. I can download this file with ESP8266 but how should I update STM32 firmware with this file?
In other words, how can I perform OTA?
STM32F1 have an embedded bootloader you can use through uart. Details are here: AN2606 and here AN3155
You can make your own: Partition your flash and save one part for the bootloader and one for the application. The former should check for some signal to update the latter. Afterwards the bootloader should jump to the application.
In theory you can program also by using the debugger protocol but never saw it done, I suppose it's simply insane to do that this way.

How to flash without STLINK

My STLINKV2 is not working anymore, not detected by Linux, it failed after the first successful flash. I ordered a new one but it will take 60+ days to arrive. Meanwhile I have heard on Youtube you can program Bluepills directly by connecting cut open USB cable to certain pins and then using a jumper. But I cannot get any precie information on this, is this really possible and how?
You should use the embedded bootloader. You can flash it through several interfaces. Look at AN2606, maybe you can find an already written flasher. Good luck STM32CubeProgrammer handle it.
If you intend to program it through usb, look also at AN3156 all protocols document are referred in chapter 2 of AN2606
THOSE AREN'T CUT OPEN USB CABLES they are USB to serial adapters for arduino's bootloader
They connect them like this:
The problem is that this requires the Arduino STM32 bootloader to be flashed in it.
Another option will be to use STM32CubeProg this program allows you to program your stm over
Serial
SPI
I2C
USB
You'll need to set the BOOT0 and BOOT1 pins to the correct value (HIGH slash LOW) to allow it to go in flash mode during boot.
Here is semi outdated tutorial which tells most of the steps to program a STM using serial. (the Flash Loader Demonstrator is outdated and you should use STM32CubeProg)

Backup or read settings of a nucleo board stm32

I was wondering if it is possible to back up or read the settings of a nucleo board stm32. It is set up as a P-NUCLEO-LRWAN1 Nucleo pack. Which uses LoRaWAN to send data to a gateway and it works perfectly. I was now wondering if I could change the configuration (like lora settings, data format, etc).
I already tried using stm32 st-link utility, and Keil IDE. But they only flash or erase the board. I don't know how to read it.
I don't have any background on this so, details would be great. Apologies if I used the wrong words to describe things. Thanks!
You can read memory by "st-link utility" software (if you have st-link, of course)
Under "icon menu" you have two text fields: Address and size. Just set correct address and window below will display necessary memory region.
To save data just Select menu File->Save file...
You need to save it into the FLASH memory. FLASH memory can be erased and programed runtime. Read your micro Reference Manual where the procedure of erasing and writing the FLASH page is described in details.

MicroSD Card versus USB Flash Drive for Raspberry Pi 2

Articles on this topic from 2012 for earlier RPi hardware extolling the virtues of using an external USB flash drive are now dated.
In 2015, using Raspberry Pi 2 hardware, is there still any advantage to moving the root file system and booting from an external USB flash drive instead of just using the default microSD card?
I'm not sure if the raspberry pi bootloader is even capable of booting from USB, but I could be mistaken (there might be a way to set up an SD card to act as an intermediate step in mounting the OS from USB).
Aside from that, I can't imagine you'll notice much of a speed difference between the micro sd and a USB 2 flash drive (as far as I'm aware, the rpi doesn't have usb 3 hardware). Both will have similar life span.
Other considerations: power consumption (I believe SD has an advantage here, especially since a card will have to be used anyway to boot), quality of either device (you can buy really bad SD cards and USB flash drives alike)
I would be interested in seeing some bench marks if you decide to run any tests to see if there's a difference.
My DriveSpeed benchmark measures speed of large and small file writes and reads, plus random writing and reading. RPi 2 results for SD and USB drives are here.
http://www.roylongbottom.org.uk/Raspberry%20Pi%20Benchmarks.htm#anchor21
For booting, you need to establish which performance feature is more important and it is not just large file data transfer speed. Anyway, it mainly depends on the drive hardware performance characteristics. My system SD card can be out performed by SD cards in a USB card reader.

How does the OS interact with peripherals like sound cards/ video cards etc

As far as I understand it, any program gets compiled to a series of assembly instructions for the architecture it is running on. What I fail to understand is how the operating system interacts with peripherals such as a video card. Isn't the driver itself a series of assembly instructions for the CPU?
The only thing I can think think of is that it uses regions of memory that is then monitored by the peripheral or it uses the BUS to communicate operations and receive results. Is there a simple explanation to this process.
Sorry if this question is too general, it's something that's been bothering me.
You're basically right in your guess. Depending on the CPU architecture, peripherals might respond to "memory-mapped I/O" (where they watch for reads and writes to specific memory addresses), or to other specific I/O instructions (such as the x86 IN and OUT instructions).
Device drivers are OS-specific software, and provide an interface between the OS and the hardware.
A specific physical device either has hardware that knows how to respond to whatever signals from the CPU it monitors, or it has its own CPU and software that is often called firmware. The firmware of a device is not specific to any operating system and is usually stored in persistent memory on the device even after it is powered off. However, some peripherals might have firmware that is loaded by the device driver when the OS boots.
There are simple explanations and there are truthfull explanations - choose one!
I'll try a simple one: Along the assembly instructions, there are some, that are specialized to talk to peripherials. The hardware interprets them not by e.g. adding values in registers oder writing something to RAM, but by moving some data from a register or a region in RAM to a peripherial (or the other way round).
Inside the OS, the e.g. the sound driver is responsible for assembling some sound data along with some command data in RAM, and the OS then invokes the bus driver to issue these special instructions to move the command and data to the soundcard. The soundcard hardware will (hopefully) understand the command and interpret the data as sound it should play.