[refactor] 整理注释

kernel/memory/pmm.cpp

@@ -19,7 +19,7 @@ static inline BOOLEAN bitmap_test(UINTN idx) {
     return (g_pmm.bitmap[idx / 8] >> (idx % 8)) & 1;
 }
 
-// Clean stale entries from free list head
+// 清理空闲链表头部的过期条目
 static void clean_free_list() {
     while (g_pmm.free_list_head != NULL &&
            bitmap_test((UINTN)g_pmm.free_list_head / PAGE_SIZE)) {
@@ -58,7 +58,7 @@ EFI_STATUS pmm_init() {
 
     UINTN entry_count = map_size / desc_size;
 
-    // First pass: count total pages and find max physical address
+    // 第一遍：统计总页数并找到最大物理地址
     UINT64 max_addr = 0;
     UINT64 total_free = 0;
     for (UINTN i = 0; i < entry_count; i++) {
@@ -73,16 +73,16 @@ EFI_STATUS pmm_init() {
     g_pmm.base_addr = 0;
     g_pmm.max_addr  = max_addr;
 
-    // How many pages does the bitmap cover?
+    // 位图覆盖的页数
     UINTN total_pages = (UINTN)(max_addr / PAGE_SIZE);
     g_pmm.total_pages = total_pages;
 
-    // Bitmap size in bytes, rounded up to page boundary
+    // 位图大小（字节），向上取整到页边界
     g_pmm.bitmap_size = ((total_pages + 7) / 8);
     UINTN bitmap_pages = (g_pmm.bitmap_size + PAGE_SIZE - 1) / PAGE_SIZE;
     g_pmm.bitmap_size = bitmap_pages * PAGE_SIZE;  // round to full pages
 
-    // Place bitmap at the end of the highest free conventional memory region
+    // 将位图放在最高空闲常规内存区域的末尾
     UINT64 bitmap_addr = 0;
     for (UINTN i = 0; i < entry_count; i++) {
         EFI_MEMORY_DESCRIPTOR* desc = (EFI_MEMORY_DESCRIPTOR*)((UINT8*)mem_map + i * desc_size);
@@ -105,12 +105,12 @@ EFI_STATUS pmm_init() {
 
     g_pmm.bitmap = (UINT8*)(UINTN)bitmap_addr;
 
-    // Init bitmap: mark ALL pages as used (0xFF)
+    // 初始化位图：将所有页标记为已使用
     for (UINTN i = 0; i < g_pmm.bitmap_size; i++) {
         g_pmm.bitmap[i] = 0xFF;
     }
 
-    // Mark free pages (EfiConventionalMemory) as free in bitmap
+    // 将空闲页（EfiConventionalMemory）在位图中标记为空闲
     g_pmm.free_pages = 0;
     UINT64 bm_start_page = bitmap_addr / PAGE_SIZE;
     UINT64 bm_end_page   = (bitmap_addr + g_pmm.bitmap_size + PAGE_SIZE - 1) / PAGE_SIZE;
@@ -123,19 +123,19 @@ EFI_STATUS pmm_init() {
         UINT64 end_page   = start_page + desc->NumberOfPages;
 
         for (UINT64 p = start_page; p < end_page; p++) {
-            // Skip bitmap pages
+            // 跳过位图占用的页
             if (p >= bm_start_page && p < bm_end_page) continue;
             bitmap_clear((UINTN)p);
             g_pmm.free_pages++;
         }
     }
 
-    // Mark bitmap pages as used
+    // 将位图占用的页标记为已使用
     for (UINT64 p = bm_start_page; p < bm_end_page; p++) {
         bitmap_set((UINTN)p);
     }
 
-    // Reserve low memory (first 4 MB) — UEFI firmware may use it during BS calls
+    // 保留低内存（前 4MB）— 固件可能在 Boot Services 调用期间使用
     UINT64 low_reserve_pages = 0x400;
     for (UINT64 p = 0; p < low_reserve_pages && p < g_pmm.total_pages; p++) {
         if (!bitmap_test((UINTN)p)) {
@@ -144,7 +144,7 @@ EFI_STATUS pmm_init() {
         }
     }
 
-    // Build free list by linking free pages
+    // 通过链接空闲页构建空闲链表
     g_pmm.free_list_head = NULL;
     void* prev = NULL;
     for (UINTN i = 0; i < entry_count; i++) {