ESP8266 Community Forum

I can dump to boot ROM's content with esptool.py's dump_mem option on address 0x40000000. However, I tried the same thing on the SPI flash address (0x40200000 according to https://github.com/esp8266/esp8266-wiki/wiki/Memory-Map) and all I got was zeros back, even though I know there's something in the flash. Is there some special trick to dumping out the SPI flash? I'm most interested in looking at the content of flash offset 0x7E000, to see how the saved WiFi parameters are stored.

Did someone manage to do this? I've been trying to make a ready-to-use dump of a custom NodeMCU build with some scripts on the flash, but haven't had any luck so far.

SPI flash is only memory mapped at run time (the mapping is performed by the SDK code), so it's not mapped when esptool is running against it. But why on earth don't you just use the read_flash command to read the flash?

swarren wrote: I'm most interested in looking at the content of flash offset 0x7E000, to see how the saved WiFi parameters are stored.

Moin,

just dump 0x7e000.

Cal