const ARENA_START_PAGE: usize = 1;Expand description
First allocatable page index inside the arena.
Page 0 (VMALLOC_VIRT_START) is permanently mapped by the bootstrap frame
allocated in ensure_kernel_subtree_ready(). Keeping that mapping alive
anchors the intermediate page-table nodes (PDPT → PD → PT) so they are
inherited by every address space cloned after init() runs.
The free-extent list therefore starts at page 1.