0002 — TLSF heap over hal_heap_region
Choice. zrt::alloc uses a two-level segregated-fit allocator (O(1)) over the region returned by
hal_heap_region; its size comes from the profile (ZRT_HEAP_BYTES: 512 MiB hosts, 64 MiB rpi1, 16 MiB ps2,
256 KiB ps1, 160 KiB esp32), so --profile ps1 on a Mac runs out of memory where a PS1 would.
Debug builds use the system allocator so that ASan sees every block.