Andrew YongandChloe Bethel
0ee5777c15
mallinfo().fordblks counts only free bytes within the committed arena. On STM32WL (newlib sbrk heap) the arena grows lazily from _end toward SP, so fordblks reads near-zero at early boot even when ~48 KB of addressable space remains. This caused NodeDB::isFull() to fire prematurely and evict nodes on a freshly booted device. Fix getFreeHeap() to include uncommitted sbrk headroom (SP - sbrk(0)) so the returned value reflects true available memory throughout the boot lifecycle. Introduce MESHTASTIC_DYNAMIC_SBRK_HEAP as an opt-in build flag (set in stm32.ini) so the fix is gated to platforms with a dynamic sbrk heap rather than a static heap. Future platforms with the same heap model can opt in by adding this flag. Signed-off-by: Andrew Yong <me@ndoo.sg> Assisted-by: Claude Sonnet 4.6 <noreply@anthropic.com>
Meshtastic Firmware
Overview
This repository contains the official device firmware for Meshtastic, an open-source LoRa mesh networking project designed for long-range, low-power communication without relying on internet or cellular infrastructure. The firmware supports various hardware platforms, including ESP32, nRF52, RP2040/RP2350, and Linux-based devices.
Meshtastic enables text messaging, location sharing, and telemetry over a decentralized mesh network, making it ideal for outdoor adventures, emergency preparedness, and remote operations.
Get Started
- 🔧 Building Instructions – Learn how to compile the firmware from source.
- ⚡ Flashing Instructions – Install or update the firmware on your device.
Join our community and help improve Meshtastic! 🚀
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