diff --git a/Ubiquitous/XiZi_AIoT/hardkernel/mmu/arm/armv8-a/cortex-a55/3568/memlayout.h b/Ubiquitous/XiZi_AIoT/hardkernel/mmu/arm/armv8-a/cortex-a55/3568/memlayout.h
index 650eb2080..dd761f4f2 100644
--- a/Ubiquitous/XiZi_AIoT/hardkernel/mmu/arm/armv8-a/cortex-a55/3568/memlayout.h
+++ b/Ubiquitous/XiZi_AIoT/hardkernel/mmu/arm/armv8-a/cortex-a55/3568/memlayout.h
@@ -36,8 +36,8 @@ Modification:
 /* A55 physical memory layout */
 #define PHY_MEM_BASE            (0x0000000010000000ULL)
 #define PHY_USER_FREEMEM_BASE   (0x0000000040000000ULL)
-#define PHY_USER_FREEMEM_TOP    (0x0000000050000000ULL)
-#define PHY_MEM_STOP            (0x0000000050000000ULL)
+#define PHY_USER_FREEMEM_TOP    (0x0000000080000000ULL)
+#define PHY_MEM_STOP            (0x0000000080000000ULL)
 
 /* PTE-PAGE_SIZE */
 #define LEVEL4_PTE_SHIFT    12
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/include/buddy.h b/Ubiquitous/XiZi_AIoT/softkernel/include/buddy.h
index 3a657aec1..d7cd11556 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/include/buddy.h
+++ b/Ubiquitous/XiZi_AIoT/softkernel/include/buddy.h
@@ -37,7 +37,7 @@ Modification:
 #include <stdbool.h>
 #include <stdint.h>
 
-#define MAX_BUDDY_ORDER (10)
+#define MAX_BUDDY_ORDER (12)
 
 #define FREE_LIST_INDEX(order) \
     (1 << order)
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/memory/pagetable.c b/Ubiquitous/XiZi_AIoT/softkernel/memory/pagetable.c
index 74759524c..3ab681281 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/memory/pagetable.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/memory/pagetable.c
@@ -51,7 +51,7 @@ static bool _new_pgdir(struct TopLevelPageDirectory* pgdir)
     return true;
 }
 
-static bool _map_pages(uintptr_t* pgdir, uintptr_t vaddr, uintptr_t paddr, int len, uintptr_t attr)
+static bool _map_pages(uintptr_t* pgdir, uintptr_t vaddr, uintptr_t paddr, intptr_t len, uintptr_t attr)
 {
     assert(len >= 0);
     vaddr = ALIGNDOWN(vaddr, LEVEL4_PTE_SIZE);
@@ -140,7 +140,7 @@ static bool _map_user_pages(uintptr_t* pgdir, uintptr_t vaddr, uintptr_t paddr,
         _p_pgtbl_mmu_access->MmuUsrDevPteAttr(&mem_attr);
     }
 
-    return _map_pages(pgdir, vaddr, paddr, len, mem_attr);
+    return _map_pages(pgdir, vaddr, paddr, (intptr_t)len, mem_attr);
 }
 
 /// assume that a user pagedir is allocated from [0, size)
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_kill.c b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_kill.c
index dbb11d0e1..9510ca226 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_kill.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/syscall/sys_kill.c
@@ -53,6 +53,17 @@ int sys_kill(int id)
         }
     }
 
+    struct ksemaphore* sem = NULL;
+    DOUBLE_LIST_FOR_EACH_ENTRY(sem, &xizi_task_manager.semaphore_pool.sem_list_guard, sem_list_node)
+    {
+        task = NULL;
+        DOUBLE_LIST_FOR_EACH_ENTRY(task, &sem->wait_list_guard, node)
+        {
+            sys_exit(task);
+            return 0;
+        }
+    }
+
     // check if task is a ready one
     for (int prio = 0; prio < TASK_MAX_PRIORITY; prio++) {
         DOUBLE_LIST_FOR_EACH_ENTRY(task, &xizi_task_manager.task_list_head[prio], node)