You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: services.rs
    path of file: ./repos/Sophon/sophon/src/modules
    
    the code of the file until where you have to start completion: use super::raw_module_call;
use super::MODULES;
use super::PROCESS_MANAGER;
use crate::arch::ArchContext;
use crate::arch::{Arch, TargetArch};
use crate::memory::kernel::KERNEL_HEAP;
use crate::memory::kernel::KERNEL_MEMORY
    
    fn map_device_pages(&self, frames: Range<Frame>) -> Range<Page> {
        let num_pages = Step::steps_between(&frames.start, &frames.end).unwrap();
        let pages = KERNEL_HEAP.virtual_allocate::<Size4K>(num_pages);
        for i in 0..num_pages {
            let frame = Step::forward(frames.start, i);
            let page = Step::forward(pages.start, i);
            KERNEL_MEMORY_MAPPER.map(page, frame, PageFlags::device());
        }
        pages
    }