mmu_mapin_ram_chunk
mmu_mapin_ram_chunk(0, boundary, PAGE_KERNEL_X, true);
mmu_mapin_ram_chunk(boundary, einittext8, PAGE_KERNEL_X, true);
mmu_mapin_ram_chunk(einittext8, top, PAGE_KERNEL, true);
err = mmu_mapin_ram_chunk(boundary, einittext8, PAGE_KERNEL, false);
err = mmu_mapin_ram_chunk(0, sinittext, PAGE_KERNEL_ROX, false);