Zero Allocation Array? -no-allocations flag

Using Swift
1

I am working on Embedded Swift and started to get linking errors with "undefined reference to `posix_memalign'". Seems like I have to create that function myself. Or just use -no-allocations. However in doing so I am not sure how to use I create an array with no allocation?
let BUF_SIZE = 2048
var staticBufferSent = [UInt8](repeating: 0, count: BUF_SIZE)

in function specialized static Array._allocateBufferUninitialized(minimumCapacity:)
:0: error: cannot use allocating type '_ContiguousArrayStorage' in -no-allocations mode
in function specialized _ContiguousArrayBuffer._consumeAndCreateNew(bufferIsUnique:minimumCapacity:growForAppend:)
error: cannot use allocating type '_ContiguousArrayStorage' in -no-allocations mode
32 | var staticBufferSent = [UInt8](repeating: 0, count: BUF_SIZE)
| `- error: cannot use allocating type '_ContiguousArrayStorage' in -no-allocations mode

2

You would have to write your own allocator or vendor existing ones available in the open source. Ideally your MCU would provide some allocator library (like Pico SDK for Raspberry Pi Pico).

If you do proceed with your own allocator, consult with your microcontroller documentation on which memory address ranges are safe to use, as it wouldn't be a good idea to write to hardware registers or overwrite executable code by accident.