Virtual Flasher

Flash memory access is emulated using SPI Flash.

This Component implements make targets to operate on the flash backing file in a similar way to flashing a real device.

Build Variables

The following options are interpreted and used to provide command-line parameters to the emulator executable:


Full path to the flash backing file


This defaults to a combination of the above variables, but you can override if necessary.

The size of the flash memory is set via Hardware configuration.

See Esptool for details and other applicable variables.

Build targets

  • make flashinit to clear and reset the file.

  • make flashfs to copy the generated SPIFFS image into the backing file.

  • make flash writes out all required images to the backing file. For now, this is the same as make flashfs but that will change when support is added for custom user images.


Used by

Environment Variables

SoC support

  • host