Partition Table/Option for 16MB flash (and 32MB flash)

[hamza765]

Related area

Board Support

Hardware specification

ESP32-WROVER-B

Is your feature request related to a problem?

I'm trying to flash my wrover-b with a 16MB flash partition, but i can't find any support at all for that. There is a option for (2mb app/12.5mb fat) but i'm using LittleFS, so that won't work. I'm currently stuck using No OTA (1mb app/ 3mb spiffs) which works, but only allows for 25% of my total capacity. Additionally, we have a order of chips coming in soon that will have 32MB total capacity (256Mb) of NOR flash mem. so it'll be even smaller of a ratio

Describe the solution you'd like

A custom board template, partition table, or just a start point for someone completely new to the world of embedded systems. I've googled so much for an answer before coming here as this is a last resort of sorts. I'd make the custom table, but don't really understand the mem address or size on the custom tables i've seen.

Thanks in advance!

Describe alternatives you've considered

No response

Additional context

No response

I have checked existing list of Feature requests and the Contribution Guide

• I confirm I have checked existing list of Feature requests and Contribution Guide.

[Jason2866]

For 16MB a partition example. You can change like you want the OTA partitions and
SPIFFS (used for LittleFS)
Just do the hex math
esp32_partition_app2944k_spiffs10M.csv

# Name,   Type, SubType, Offset,  Size, Flags
nvs,      data, nvs,     0x9000,  0x5000,
otadata,  data, ota,     0xe000,  0x2000,
app0,     app,  ota_0,   0x10000, 0x2F0000,
app1,     app,  ota_1,   0x300000, 0x2F0000,
spiffs,   data, spiffs,  0x5F0000,0xA10000,

[VojtechBartoska]

@hamza765 Was the comment above helpful?

[hamza765]

@VojtechBartoska sort of. I'm confused on the 'hex math' part. I read in another issue that I can just leave the offsets column empty and the device will figure it out for me. So would i just set the spiffs partition to a size of 0xF42400 for a 16M flash? (and 0x1E84800 for 32M?)

[lbernstone]

You must have the first partition offset to 0x9000. You can just use size past there if you prefer. The total space on a 16M device is 0x1000000. So, 0x1000000 - 0x9000 = 0xFF7000 left. Subtract 0x5000 for the nvs partition leaves 0xFF2000. If you continue for the partitions in Jason2866's example above, you will see that it uses all the space. https://www.calculator.net/hex-calculator.html, but I'm sure you have one on your computer.

[hamza765]

@lbernstone That explains a lot! Do I need two app partitions? (app0/app1) or can i combine them both into one?

[lbernstone]

If you want OTA to work, you need two.

[hamza765]

Okay, good to know. Makes sense that they'd be equal in size. For future proofing, since i have so much space to play with, would giving each app partition like 3MB each be overkill?

[lbernstone]

No. I'd give the app even more, since you will likely realize that the filesystem is less useful than you think.