1 files changed, 99 insertions, 0 deletions
diff --git a/mirai/memory/zone/bootstrap/bootstrap.zig b/mirai/memory/zone/bootstrap/bootstrap.zig
new file mode 100644
index 0000000..8ecd0b0
--- /dev/null
+++ b/mirai/memory/zone/bootstrap/bootstrap.zig
@@ -0,0 +1,99 @@
+//! Bootstrap Zones
+
+const types = @import("../types/types.zig");
+const Zone = types.Zone;
+const ZonePageMeta = types.ZonePageMeta;
+const FreeElement = types.FreeElement;
+const page_size = types.page_size;
+const min_elem_size = types.min_elem_size;
+
+const convert = @import("../../convert/convert.zig");
+const pmm = @import("../../../pmm/pmm.zig");
+
+var zone_zone: Zone = undefined;
+var page_meta_zone: Zone = undefined;
+
+pub var early_page_metas: [4]ZonePageMeta = undefined;
+var early_meta_used: usize = 0;
+
+var initialized: bool = false;
+
+pub fn init() !void {
+    if (initialized) return;
+
+    init_zone(&zone_zone, "zone_zone", @sizeOf(Zone));
+    init_zone(&page_meta_zone, "page_meta_zone", @sizeOf(ZonePageMeta));
+
+    try expand_zone_early(&zone_zone);
+    try expand_zone_early(&page_meta_zone);
+
+    initialized = true;
+}
+
+fn init_zone(zone: *Zone, name: []const u8, elem_size: usize) void {
+    const actual_size = if (elem_size < min_elem_size) min_elem_size else elem_size;
+    const aligned_size = (actual_size + 7) & ~@as(usize, 7);
+
+    zone.elem_size = aligned_size;
+    zone.elems_per_page = page_size / aligned_size;
+    zone.partial_pages = null;
+    zone.full_pages = null;
+    zone.alloc_count = 0;
+    zone.free_count = 0;
+    zone.page_count = 0;
+
+    const copy_len = @min(name.len, 31);
+    @memcpy(zone.name[0..copy_len], name[0..copy_len]);
+    zone.name_len = @truncate(copy_len);
+}
+
+fn expand_zone_early(zone: *Zone) !void {
+    if (early_meta_used >= early_page_metas.len) return error.OutOfEarlyMeta;
+
+    const phys = try pmm.allocate_page();
+    const virt = convert.phys_to_virt(phys);
+
+    const meta = &early_page_metas[early_meta_used];
+    early_meta_used += 1;
+
+    meta.zone = zone;
+    meta.page_phys = phys;
+    meta.page_virt = virt;
+    meta.free_list = null;
+    meta.in_use = 0;
+    meta.next = zone.partial_pages;
+    zone.partial_pages = meta;
+    zone.page_count += 1;
+
+    carve_page(zone, meta, virt);
+}
+
+fn carve_page(zone: *Zone, meta: *ZonePageMeta, page_virt: u64) void {
+    const base: [*]u8 = @ptrFromInt(page_virt);
+    var offset: usize = 0;
+
+    while (offset + zone.elem_size <= page_size) : (offset += zone.elem_size) {
+        const elem: *FreeElement = @ptrCast(@alignCast(base + offset));
+        elem.next = meta.free_list;
+        meta.free_list = elem;
+    }
+}
+
+pub fn get_zone_zone() *Zone {
+    return &zone_zone;
+}
+
+pub fn get_page_meta_zone() *Zone {
+    return &page_meta_zone;
+}
+
+pub fn is_initialized() bool {
+    return initialized;
+}
+
+pub fn is_early_meta(meta: *const ZonePageMeta) bool {
+    const meta_addr = @intFromPtr(meta);
+    const early_start = @intFromPtr(&early_page_metas);
+    const early_end = early_start + @sizeOf(@TypeOf(early_page_metas));
+    return meta_addr >= early_start and meta_addr < early_end;
+}