ESP8266 Community Forum

- Thu Sep 03, 2015 3:48 pm #27745

If you're using a command line utility to download to Flash, you'll have to specify loading the irom0.text image at 0x10000 rather than at the usual 0x40000 for the non-OTA boot scheme.

Or make a "composite" image by padding the 0x00000 file to 0x10000 and then append the 0x10000 (which is what I do).

- Thu Sep 03, 2015 5:04 pm #27749

Or make a "composite" image by padding the 0x00000 file to 0x10000 and then append the 0x10000.

True, the .irom0 code is all position-independent since it is copied to the iram cache at execution time.

My esp_tool can build the composite file with 0xff padding if you choose. It can also build and download "sparse" combined files. which eliminates the need to transmit the padding bytes to the device. Depending on the amount of padding, this can speed up Flashing considerably.

Don Kinzer
ZBasic Microcontrollers
http://www.zbasic.net

- Fri Sep 04, 2015 1:28 pm #27830 In my case the gap is only about 12 kbytes, the 0x00000 section is iram plus some additional data, that makes up a large part of the first 64 kbytes anyway.