Andrew Yong 0ee5777c15 stm32wl(mem): fix getFreeHeap() underreporting on dynamic sbrk heap ...

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>

2026-04-16 13:57:21 +01:00

..

esp32

Add RADIOLIB_EXCLUDE_LR2021 in places that excluded LR11x0 (#10112)

2026-04-14 16:55:11 +02:00

esp32c3

Switch PlatformIO deps from PIO Registry to tagged GitHub zips (#10142)

2026-04-12 17:06:57 -05:00

esp32c6

Switch PlatformIO deps from PIO Registry to tagged GitHub zips (#10142)

2026-04-12 17:06:57 -05:00

esp32s2

Develop to master (#9618)

2026-02-19 07:16:33 -06:00

esp32s3

Add RADIOLIB_EXCLUDE_LR2021 in places that excluded LR11x0 (#10112)

2026-04-14 16:55:11 +02:00

native

Add PortduinoSetOptions to overwrite the realhardware bool (#10157)

2026-04-14 21:32:48 +02:00

nrf52840

Add RADIOLIB_EXCLUDE_LR2021 in places that excluded LR11x0 (#10112)

2026-04-14 16:55:11 +02:00

rp2040

Develop to master (#9618)

2026-02-19 07:16:33 -06:00

rp2350

Develop to master (#9618)

2026-02-19 07:16:33 -06:00

stm32

stm32wl(mem): fix getFreeHeap() underreporting on dynamic sbrk heap

2026-04-16 13:57:21 +01:00