MEMMAP_MEMORY_UNUSABLE 136 kernel/arch/amd64/src/mm/frame.c if (e820table[i].type <= MEMMAP_MEMORY_UNUSABLE) MEMMAP_MEMORY_UNUSABLE 136 kernel/arch/ia32/src/mm/frame.c if (e820table[i].type <= MEMMAP_MEMORY_UNUSABLE)HelenOS homepage, sources at GitHub