The following are daily builds of the ESP8266 firmware. This will work on
boards with at least 2MiB of flash.  They have the latest features and bug
fixes, WebREPL is not automatically started, and debugging is enabled by
default.

For boards with 1MiB or 512kiB of flash, two variants are provided with reduced
functionality. The 1MiB variant removes asyncio and FAT-filesystem support as
well as some modules from micropython-lib. The 512kiB variant further removes
all filesystem support, as well as framebuffer support, some Python language
features, and has less detailed error messages.

Boards with more than 4MiB of flash (e.g. 8MiB or 16MiB) need an extra
step to write the `esp_init_data` RF calibration data, otherwise WiFi will not
start. See [Boards with more than 4MB of flash](https://docs.micropython.org/en/latest/esp8266/tutorial/intro.html#boards-with-more-than-4mb-of-flash)
in the tutorial for details.

Note: v1.12-334 and newer (including v1.13) require an ESP8266 module with
2MiB of flash or more, and use littlefs as the filesystem by default.  When
upgrading from older firmware please backup your files first, and either
erase all flash before upgrading, or after upgrading execute
`vfs.VfsLfs2.mkfs(bdev)`.
