Constant SYS_MEM_REGION_MAP 

pub const SYS_MEM_REGION_MAP: usize = 106; // 106usize

Map an exported memory region into the current address space.

• region_handle: capability handle from SYS_MEM_REGION_EXPORT
• addr: desired virtual address (0 = kernel chooses)
• len: length in bytes

Returns the mapped virtual address.