Partition Layout

The partition table determines application capacity, LittleFS capacity, and OTA availability. The source currently uses partitions/4MB.csv, partitions/8MB.csv, and partitions/16MB.csv; platformio.ini is the authoritative environment mapping.

Layout Overview

File	Flash	app0	app1	LittleFS	OTA
4MB.csv	4MB	0x10000 / 2.94MB	None	0x300000 / 1MB	No
8MB.csv	8MB	0x10000 / 3.5MB	0x390000 / 3.5MB	0x710000 / 960KB	Yes
16MB.csv	16MB	0x10000 / 7MB	0x710000 / 7MB	0xE10000 / about 1.94MB	Yes

All layouts include nvs and otadata. The LittleFS partition uses the CSV subtype name spiffs for Arduino-ESP32 compatibility; the runtime filesystem is still LittleFS.

Environment Mapping

Environment	Partition	OTA
esp32-F4R0	4MB.csv	No
esp32c3-F4R0	4MB.csv	No
esp32c6-F4R0	4MB.csv	No
esp32-F8R0	8MB.csv	Yes
esp32-F8R8	8MB.csv	Yes
esp32c6-F8R0	8MB.csv	Yes
esp32s3-F8R0	8MB.csv	Yes
esp32s3-F8R8	8MB.csv	Yes
esp32s3-F16R8	16MB.csv	Yes

OTA Constraints

• OTA routes are registered only when app1 exists and FASTBEE_ENABLE_OTA=1.
• A 4MB environment returns HTTP 501 for OTA operations. This is a permanent partition limitation; flash a merged image instead of retrying.
• Firmware for an 8MB or 16MB environment must fit its app partition and pass the runtime memory guard before upgrade starts.
• After OTA, wait for restart, poll the unauthenticated /api/health, then log in again and verify the version.

LittleFS Constraints

• Web resources, /config, and logs share the LittleFS partition.
• Use deploy.ps1 or gzip-www.js to create an isolated staging directory; do not upload source data/www directly.
• Partition table, firmware, and LittleFS must come from the same build. Updating only one can leave Web resources and APIs out of sync.

Changing Layout or Firmware

1. Export the device configuration.
2. Confirm Flash size and target environment.
3. Erase the full Flash when changing layout or migrating from another project.
4. Flash bootloader, partition table, application, and LittleFS together; merged images use address 0x0.
5. Reconfigure networking and check /api/system/info, /api/health, and /api/system/capabilities.

See OTA Upgrade for the upgrade workflow and Build Configuration for build commands.