esp_flash support (QEMU-49) about qemu HOT 7 CLOSED

@timkoers this should be already supported. Just keep in mind that the emulation performance is pretty low, since every operation is first represented as SPI commands (serialized to bytes) which are then handled by SPI Flash chip emulation layer. If you are running one of the flash related examples, you need to wait a fair bit, especially if the code is formatting a large partition.

from qemu.

The examples that I could find where of the SD MMC and the internal flash. I'd like to emulate an external SPI flash. Whilst your at it, would you mind providing an example on how to create such a image to be used during qemu emulation?

from qemu.

Okay, I understand your use case now. Indeed there is no support for emulating external flash in QEMU with ESP32. In principle this should be doable, need to create another instance of the SPI controller (SPI2) and attach a flash chip to it in the emulator.

I would suggest you to try the emulation of the internal flash, first. It's pretty slow, so please make sure it is okay for your purposes before we try to add support for external flash.

Regarding creating the flash image of an app, you can follow the instructions in this wiki section: https://github.com/espressif/qemu/wiki#build-test-app

from qemu.

Can I also use the vfs_fat filesystem on the internal flash, it doesn't look so

I do see that I can use the SD card with the FatFS filesystem, but then I'll need to change every initialization function to use the SD card instead of the spi flash when unit testing, which defeats the point of unit testing, since I want to test if the SPI flash works, instead of the SD card 😋

from qemu.

You should be able to use the filesystem in the internal flash, please refer to storage/wear_levelling example in ESP-IDF.

from qemu.

Closing this issue since support for esp_vfs_fat_spiflash_mount for the internal flash is currently available, and works in QEMU.

from qemu.

I'd still like to see this getting implemented for an external flash since I don't want to mess around with the internal flash as that contains the actual program.

from qemu.