Function otPlatCAlloc 

pub unsafe extern "C" fn otPlatCAlloc(
    aNum: usize,
    aSize: usize,
) -> *mut c_void

Dynamically allocates new memory. On platforms that support it, they should redirect to calloc. For those that don’t support calloc, they should implement the standard calloc behavior.

See: https://man7.org/linux/man-pages/man3/calloc.3.html

Is required for OPENTHREAD_CONFIG_HEAP_EXTERNAL_ENABLE.

@param[in] aNum The number of blocks to allocate @param[in] aSize The size of each block to allocate

@retval void* The pointer to the front of the memory allocated @retval NULL Failed to allocate the memory requested.