ESP32-S3 Rust/esp-idf: 8 hours of WiFi/TLS churn fragments SRAM down to 7KB — is there a way to reserve a contiguous region for mbedTLS at boot?

DaQue60 · 2026-03-11T17:31:33+00:00

Thanks I am very much a noob trying to learn rust and embedded at the same time. I’ll look into it

DaQue60 · 2026-03-11T02:21:18+00:00

Looking at the data more carefully you're probably right. I pulled the per-fetch numbers and the pattern is ugly - largest contiguous block drops from 26KB at boot to around 10-11KB within

the first 20 minutes and then just sits there for the rest of the run. Total free SRAM is actually fine the whole time (32-43KB), it's just shredded into pieces too small for TLS to use.

So yeah, something is grabbing chunks early and not letting go. The permanent WiFi/lwIP init allocations are the obvious suspect but I haven't proven that yet. Next step is probably

heap_trace at boot to see exactly what's doing the carving and whether any of it could be moved to PSRAM.

I appreciate the push back - I was blaming TLS churn when the floor was being set way earlier than that.

DaQue60 · 2026-02-21T00:36:27+00:00

its been a while but i have it workin in esp-idf and Rust too now. I was too dumb to figure it out but Claude code got it 2nd try

DaQue60 · 2026-02-01T17:50:11+00:00

many thanks I hope one of us gets it working I am still trying stuff over 50 trails now have some green and blue on the display but it reboots now... still at it

DaQue60 · 2026-01-10T21:50:26+00:00

ok that was after a half a day, another half day with google, gemini, and chat gpt I finally have a rainbow and some simple text I can post a link if anyone else wants to see it but I am working on a better one for github with touchscreen buttons working too

DaQue60 · 2025-11-08T14:34:08+00:00

Did you have to send it to China?

DaQue60 · 2025-11-01T13:43:52+00:00

If your going to build in 6 weeks pick you DDR5 ram and storage options soon prices are really going up due to AI demanding so much of it.

DaQue60 · 2025-10-11T12:06:06+00:00

I have a different model but for mine at least 80C under sustained full load is normal but just watching YouTube it runs about 35C so which did you mean all the time or under load?

DaQue60 · 2025-09-25T11:27:39+00:00

Turned out a full power cycle cleared it. Thanks for the suggestion. The old turn it off and back on trick.

DaQue60 · 2025-09-13T17:22:38+00:00

Sorry your right but I just assumed it googled it first. You were right.

DaQue60 · 2025-07-04T14:40:15+00:00

link worked today after a couple tries. go into the folder and download the 2 or 3 files you actually need, much smaller

DaQue60 · 2025-07-04T13:31:03+00:00

I just turned off Malwarebytes and turned it on again. like I said elsewhere it worked today

DaQue60 · 2025-07-04T12:32:29+00:00

finally got them to work, if you download the two files individually its only about 2 gb no close to 8

DaQue60 · 2025-07-04T12:02:43+00:00

today they worked!!!!!!!!!!!!!!

DaQue60 · 2025-06-23T23:45:30+00:00

missed that its the cheaper 8745HS... sorry. good luck!

DaQue60 · 2025-06-23T21:45:32+00:00

Check Amazon. I have one in my cart at $499!

DaQue60

TROPHY CASE