QUERY · ISSUE

esp8266, 16MB

openby permaBoxopened 2019-05-01updated 2026-03-24

port-esp8266proposed-close

Hi,
the latest mpy version can't be flashed to support 16MB flash.
the esp will be end up in a reset -loop.
with the version before it works as expected!

CANDIDATE · ISSUE

Flashing Micropython 1.21 to an ESP-01m not possible

closedby besiopened 2023-12-23updated 2024-01-02

I was not able to flash my ESP-01m with the latest micropython version 1.21.
As soon as I did a fallback onto 1.20 I could successfully flash my device and get a REPL.

EXPECTED BEHAVIOUR

I flash the device and get a REPL when connecting to it via TTL cable.

ACTUAL BEHAVIOUR

I can flash the device and "Thonny" tells me that the flashing was complete. However when I disable the boot loader mode and reset the device the device fails to respond.

I did use the latest Thonny 4.1.4 which uses ESPTool in the background.

I quite like the form factor of the ESP-01m so I would hope that micropython continues to work on that device.

Assessment

S Sonnet · medium

Both report ESP8266 boot failure regressions after a MicroPython upgrade, with the previous version working correctly. However, the hardware is quite different: #4734 targets a 16MB flash device (large flash, non-standard for ESP8266), while #13264 targets an ESP-01m which typically has 1MB flash (very constrained). Flash layout and configuration code paths differ substantially between these sizes, making a shared root cause plausible but not certain. The symptoms (reset loop / no REPL after flash) are consistent but could stem from separate flash-size-related regressions.

Suggested action

Keep both open independently. Cross-reference them as related ESP8266 boot regression reports. A maintainer investigating either should check whether the flash size handling in esp8266 boards/flashbdev changed between the respective working and broken versions, as the fix for one may or may not address the other.

esp8266, 16MB

Flashing Micropython 1.21 to an ESP-01m not possible

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