Heap

Configuration variables

ENABLE_CUSTOM_HEAP

If your application is experiencing heap fragmentation then you can try the alternative heap.

undefined (default)

OFF, use standard heap

1

Use UMM Malloc.

Warning

Do not enable custom heap allocation and -mforce-l32 compiler flag at the same time.

UMM_FUNC_IRAM

Default: 1 (enabled)

Custom heap functions are stored in IRAM by default for performance reasons.

If you need the IRAM (about 1.5K bytes) then disable this option:

make ENABLE_CUSTOM_HEAP=1 UMM_FUNC_IRAM=0

References

• Source Code

Used by

• Sming (Esp32) Component

• Sming (Esp8266) Component

• Sming (Host) Component

Environment Variables

• ENABLE_CUSTOM_HEAP

• UMM_FUNC_IRAM

• UMM_POISON_CHECK

SoC support

• esp8266

Submodule: umm_malloc

• umm_malloc - Memory Manager For Small(ish) Microprocessors
  • Acknowledgements
  • Usage
  • API
  • Background
  • Detailed Description
    • Operation of malloc right after system startup
    • Operation of malloc when we have reached the end of the free list and there is no block large enough to accommodate the request.
    • Operation of malloc when we have found a block (cf) that will fit the current request of b units exactly
    • Operation of malloc when we have found a block that will fit the current request of b units with some left over
    • Free Scenarios
    • Realloc Scenarios