ESPTOOL and WRITE PROTECT

[scargill]

#i and others are having a lot of trouble since changes to the SDK around 1.5.4 - and part of that is to do with FLASH.

Am I right in saying that this

c:/espressif/utils/esptool.exe -p COM3 -b 115200 erase_flash

Should erase let's say the 4MB FLASH (32Mbit) on an ESP12 INCLUDING the system parameter area right up at the top?

And regarding that area - how does that get programmed?

If I use Richard Burton's RBOOT at 0000 and my code at say 2000h - what is it that sets up the system parameter block? And is that 16K area normally write protected? I ask that becasuse using the ESP8266FLASHER tool, writing a blank 1MEG file at the top meg fails - but writing it 16K lower seems to work indicating something is stopping me erasing that top block?