diff --git a/Ubiquitous/XiZi_AIoT/hardkernel/arch/arm/armv7-a/cortex-a9/preboot_for_imx6q-sabrelite/nxp_imx6q_sabrelite.lds b/Ubiquitous/XiZi_AIoT/hardkernel/arch/arm/armv7-a/cortex-a9/preboot_for_imx6q-sabrelite/nxp_imx6q_sabrelite.lds
index 7a23ca569..ed1525396 100644
--- a/Ubiquitous/XiZi_AIoT/hardkernel/arch/arm/armv7-a/cortex-a9/preboot_for_imx6q-sabrelite/nxp_imx6q_sabrelite.lds
+++ b/Ubiquitous/XiZi_AIoT/hardkernel/arch/arm/armv7-a/cortex-a9/preboot_for_imx6q-sabrelite/nxp_imx6q_sabrelite.lds
@@ -77,6 +77,10 @@ BOOT_STACK_SIZE = 0x4000;
 RAM_VECTORS_SIZE = 72;
 
 /* Specify the memory areas */
+/*
+	ddr3: physical area: [0x10000000, 0x50000000);
+	virt_ddr3: virt area exclude boot(start_sec), that will be [0x90000000 + 0x11000, 0xD0000000)
+*/
 MEMORY
 {
     ocram (rwx)  			: ORIGIN = 0x00900000, LENGTH = 256K
@@ -154,7 +158,7 @@ SECTIONS
 		PROVIDE(boot_end_addr = .);
 	} > ddr3
 
-	/* Other Kernel code is placed over 0x80000000 + 128KB. */
+	/* Other Kernel code is placed over 0x10011000(phy) and 0x90011000(virt). */
 	.text : AT(0x10011000) {
 		*(.vectors)
 		. = ALIGN(0x1000);
diff --git a/Ubiquitous/XiZi_AIoT/hardkernel/intr/arm/armv7-a/cortex-a9/imx6q-sabrelite/trap_common.c b/Ubiquitous/XiZi_AIoT/hardkernel/intr/arm/armv7-a/cortex-a9/imx6q-sabrelite/trap_common.c
index b564f8cb7..47dede1b9 100644
--- a/Ubiquitous/XiZi_AIoT/hardkernel/intr/arm/armv7-a/cortex-a9/imx6q-sabrelite/trap_common.c
+++ b/Ubiquitous/XiZi_AIoT/hardkernel/intr/arm/armv7-a/cortex-a9/imx6q-sabrelite/trap_common.c
@@ -156,29 +156,11 @@ static uint32_t _hw_cur_int_num(uint32_t int_info)
     return int_info & 0x1FF;
 }
 
-static uint32_t _hw_cur_int_cpu(uint32_t int_info)
-{
-    return (int_info >> 10) & 0x7;
-}
-
 static void _hw_after_irq(uint32_t int_info)
 {
     gic_write_end_of_irq(int_info);
 }
 
-static int _is_interruptable(void)
-{
-    uint32_t val;
-
-    __asm__ __volatile__(
-        "mrs %0, cpsr"
-        : "=r"(val)
-        :
-        :);
-
-    return !(val & DIS_INT);
-}
-
 int _cur_cpu_id()
 {
     return cpu_get_current();
@@ -196,10 +178,8 @@ static struct XiziTrapDriver xizi_trap_driver = {
 
     .bind_irq_handler = _bind_irq_handler,
 
-    .is_interruptable = _is_interruptable,
     .hw_before_irq = _hw_before_irq,
     .hw_cur_int_num = _hw_cur_int_num,
-    .hw_cur_int_cpu = _hw_cur_int_cpu,
     .hw_after_irq = _hw_after_irq,
 };
 
diff --git a/Ubiquitous/XiZi_AIoT/hardkernel/intr/arm/armv7-a/cortex-a9/zynq7000-zc702/trap_common.c b/Ubiquitous/XiZi_AIoT/hardkernel/intr/arm/armv7-a/cortex-a9/zynq7000-zc702/trap_common.c
index 5cd8145a5..f706f58dd 100644
--- a/Ubiquitous/XiZi_AIoT/hardkernel/intr/arm/armv7-a/cortex-a9/zynq7000-zc702/trap_common.c
+++ b/Ubiquitous/XiZi_AIoT/hardkernel/intr/arm/armv7-a/cortex-a9/zynq7000-zc702/trap_common.c
@@ -163,29 +163,11 @@ static uint32_t _hw_cur_int_num(uint32_t int_info)
     return int_info & XSCUGIC_ACK_INTID_MASK;
 }
 
-static uint32_t _hw_cur_int_cpu(uint32_t int_info)
-{
-    return (int_info >> 5) & 0x3;
-}
-
 static void _hw_after_irq(uint32_t int_info)
 {
     XScuGic_CPUWriteReg(&IntcInstance, XSCUGIC_EOI_OFFSET, int_info);
 }
 
-static int _is_interruptable(void)
-{
-    uint32_t val;
-
-    __asm__ __volatile__(
-        "mrs %0, cpsr"
-        : "=r"(val)
-        :
-        :);
-
-    return !(val & DIS_INT);
-}
-
 int _cur_cpu_id()
 {
     return cpu_get_current();
@@ -203,10 +185,8 @@ static struct XiziTrapDriver xizi_trap_driver = {
 
     .bind_irq_handler = _bind_irq_handler,
 
-    .is_interruptable = _is_interruptable,
     .hw_before_irq = _hw_before_irq,
     .hw_cur_int_num = _hw_cur_int_num,
-    .hw_cur_int_cpu = _hw_cur_int_cpu,
     .hw_after_irq = _hw_after_irq,
 };
 
diff --git a/Ubiquitous/XiZi_AIoT/hardkernel/intr/trap_common.h b/Ubiquitous/XiZi_AIoT/hardkernel/intr/trap_common.h
index c86c3cc47..232cb6b7b 100644
--- a/Ubiquitous/XiZi_AIoT/hardkernel/intr/trap_common.h
+++ b/Ubiquitous/XiZi_AIoT/hardkernel/intr/trap_common.h
@@ -56,8 +56,6 @@ struct irq_table_entry {
 struct XiziTrapDriver {
     /* irq number table*/
     struct irq_table_entry sw_irqtbl[NR_IRQS];
-    /* current irq number happening in cpu*/
-    uint32_t curr_int[NR_CPU];
 
     void (*sys_irq_init)(int);
     int (*cur_cpu_id)();
@@ -71,11 +69,9 @@ struct XiziTrapDriver {
     void (*bind_irq_handler)(int, irq_handler_t);
 
     /* check if no if interruptable */
-    int (*is_interruptable)();
     /* code runs before irq handling */
     uint32_t (*hw_before_irq)();
     uint32_t (*hw_cur_int_num)(uint32_t int_info);
-    uint32_t (*hw_cur_int_cpu)(uint32_t int_info);
     /* code runs after irq handling */
     void (*hw_after_irq)(uint32_t int_info);
 };
diff --git a/Ubiquitous/XiZi_AIoT/hardkernel/mmu/arm/armv7-a/cortex-a9/mmu.c b/Ubiquitous/XiZi_AIoT/hardkernel/mmu/arm/armv7-a/cortex-a9/mmu.c
index 50d783b90..16d78663d 100644
--- a/Ubiquitous/XiZi_AIoT/hardkernel/mmu/arm/armv7-a/cortex-a9/mmu.c
+++ b/Ubiquitous/XiZi_AIoT/hardkernel/mmu/arm/armv7-a/cortex-a9/mmu.c
@@ -38,24 +38,6 @@ Modification:
 // extern struct MmuCommonDone mmu_common_done;
 static struct MmuDriverRightGroup right_group;
 
-void load_pgdir_critical(uintptr_t pgdir_paddr, struct TraceTag* intr_driver_tag)
-{
-
-    /* get cache driver */
-    struct ICacheDone* p_icache_done = AchieveResource(&right_group.icache_driver_tag);
-    struct DCacheDone* p_dcache_done = AchieveResource(&right_group.dcache_driver_tag);
-
-    /* get intr driver */
-    struct XiziTrapDriver* p_intr_driver = AchieveResource(intr_driver_tag);
-
-    p_intr_driver->cpu_irq_disable();
-    TTBR0_W((uint32_t)pgdir_paddr);
-    CLEARTLB(0);
-    p_icache_done->invalidateall();
-    p_dcache_done->flushall();
-    p_intr_driver->cpu_irq_enable();
-}
-
 void load_pgdir(uintptr_t pgdir_paddr)
 {
     /* get cache driver */
@@ -94,7 +76,6 @@ static struct MmuCommonDone mmu_common_done = {
     .MmuUsrDevPteAttr = GetUsrDevPteAttr,
     .MmuKernPteAttr = GetKernPteAttr,
 
-    .LoadPgdirCrit = load_pgdir_critical,
     .LoadPgdir = load_pgdir,
     .TlbFlushAll = tlb_flush_all,
     .TlbFlush = tlb_flush_range,
diff --git a/Ubiquitous/XiZi_AIoT/hardkernel/mmu/mmu_common.h b/Ubiquitous/XiZi_AIoT/hardkernel/mmu/mmu_common.h
index b979f80e8..4170afc0a 100644
--- a/Ubiquitous/XiZi_AIoT/hardkernel/mmu/mmu_common.h
+++ b/Ubiquitous/XiZi_AIoT/hardkernel/mmu/mmu_common.h
@@ -27,7 +27,6 @@ struct MmuCommonDone
     void (*MmuUsrDevPteAttr)(uintptr_t* attr);
     void (*MmuKernPteAttr)(uintptr_t* attr);
 
-    void (*LoadPgdirCrit)(uintptr_t pgdir_paddr, struct TraceTag*);
     void (*LoadPgdir)(uintptr_t pgdir_paddr);
     void (*TlbFlushAll)();
     void (*TlbFlush)(uintptr_t vaddr, int len);
diff --git a/Ubiquitous/XiZi_AIoT/services/app/Makefile b/Ubiquitous/XiZi_AIoT/services/app/Makefile
index 3c5ab1a89..ac07d2f9f 100644
--- a/Ubiquitous/XiZi_AIoT/services/app/Makefile
+++ b/Ubiquitous/XiZi_AIoT/services/app/Makefile
@@ -19,6 +19,8 @@ c_useropts = -O0
 INC_DIR = 	-I$(KERNEL_ROOT)/services/shell/letter-shell \
 			-I$(KERNEL_ROOT)/services/lib/ipc \
 			-I$(KERNEL_ROOT)/services/lib/memory \
+			-I$(KERNEL_ROOT)/services/lib/serial \
+			-I$(KERNEL_ROOT)/services/lib/usyscall \
 			-I$(KERNEL_ROOT)/services/fs/libfs \
 			-I$(KERNEL_ROOT)/services/boards/$(BOARD) \
 			-I$(KERNEL_ROOT)/services/app 
@@ -37,44 +39,44 @@ bin:
 	@mkdir -p bin
 
 ifeq ($(BOARD), imx6q-sabrelite)
-test_irq_send: test_irq_sender.o usyscall.o libserial.o
+test_irq_send: test_irq_sender.o usyscall.o arch_usyscall.o libserial.o
 	@${ld} ${user_ldflags} -e main -o $@ $^ ${board_specs}
 	@${objdump} -S $@ > $@.asm
 endif
 
-test_irq_block: test_irq_block.o libserial.o libipc.o session.o usyscall.o libmem.o
+test_irq_block: test_irq_block.o libserial.o libipc.o session.o usyscall.o arch_usyscall.o libmem.o
 	@${ld} ${user_ldflags} -e main -o $@ $^ ${board_specs}
 	@${objdump} -S $@ > $@.asm
 
-test_irq_hdlr: test_irq_handler.o libserial.o libipc.o session.o usyscall.o libmem.o
+test_irq_hdlr: test_irq_handler.o libserial.o libipc.o session.o usyscall.o arch_usyscall.o libmem.o
 	@${ld} ${user_ldflags} -e main -o $@ $^ ${board_specs}
 	@${objdump} -S $@ > $@.asm
 
-shell: shell_port.o libserial.o shell_cmd_list.o shell.o shell_ext.o libfs_to_client.o libipc.o session.o usyscall.o libmem.o
+shell: shell_port.o libserial.o shell_cmd_list.o shell.o shell_ext.o libfs_to_client.o libipc.o session.o usyscall.o arch_usyscall.o libmem.o
 	@${ld} ${user_ldflags} -e main -o $@ $^ ${board_specs}
 	@${objdump} -S $@ > $@.asm
 	
-init: init.o libfs_to_client.o libipc.o session.o libserial.o usyscall.o libmem.o
+init: init.o libfs_to_client.o libipc.o session.o libserial.o usyscall.o arch_usyscall.o libmem.o
 	@${ld} ${user_ldflags} -e main -o $@ $^ ${board_specs}
 	@${objdump} -S $@ > $@.asm
 
-test_fs: test_fs.o libfs_to_client.o libipc.o session.o libserial.o usyscall.o libmem.o
+test_fs: test_fs.o libfs_to_client.o libipc.o session.o libserial.o usyscall.o arch_usyscall.o libmem.o
 	@${ld} ${user_ldflags} -e main -o $@ $^ ${board_specs}
 	@${objdump} -S $@ > $@.asm
 
-simple_client: simple_client.o libserial.o libipc.o session.o simple_service.o libfs_to_client.o usyscall.o  libmem.o
+simple_client: simple_client.o libserial.o libipc.o session.o simple_service.o libfs_to_client.o usyscall.o arch_usyscall.o  libmem.o
 	@${ld} ${user_ldflags} -e main -o $@ $^ ${board_specs}
 	@${objdump} -S $@ > $@.asm
 
-simple_server: simple_server.o libserial.o libipc.o session.o simple_service.o usyscall.o libmem.o
+simple_server: simple_server.o libserial.o libipc.o session.o simple_service.o usyscall.o arch_usyscall.o libmem.o
 	@${ld} ${user_ldflags} -e main -o $@ $^ ${board_specs}
 	@${objdump} -S $@ > $@.asm
 
-fs_server: fs_server.o libfs_to_client.o fs.o libserial.o libipc.o session.o block_io.o usyscall.o libmem.o
+fs_server: fs_server.o libfs_to_client.o fs.o libserial.o libipc.o session.o block_io.o usyscall.o arch_usyscall.o libmem.o
 	@${ld} ${user_ldflags} -e main -o $@ $^ ${board_specs}
 	@${objdump} -S $@ > $@.asm
 
-test_priority: test_priority.o libserial.o usyscall.o libmem.o
+test_priority: test_priority.o libserial.o usyscall.o arch_usyscall.o libmem.o
 	@${ld} ${user_ldflags} -e main -o $@ $^ ${board_specs}
 	@${objdump} -S $@ > $@.asm
 
diff --git a/Ubiquitous/XiZi_AIoT/services/boards/imx6q-sabrelite/Makefile b/Ubiquitous/XiZi_AIoT/services/boards/imx6q-sabrelite/Makefile
index 96a8dc345..122fb6ef6 100644
--- a/Ubiquitous/XiZi_AIoT/services/boards/imx6q-sabrelite/Makefile
+++ b/Ubiquitous/XiZi_AIoT/services/boards/imx6q-sabrelite/Makefile
@@ -15,10 +15,12 @@ c_useropts = -O0
 INC_DIR = 	-I$(KERNEL_ROOT)/services/fs/libfs \
 			-I$(KERNEL_ROOT)/services/lib/ipc \
 		  	-I$(KERNEL_ROOT)/services/lib/memory \
+			-I$(KERNEL_ROOT)/services/lib/serial \
+			-I$(KERNEL_ROOT)/services/lib/usyscall \
 			-I$(KERNEL_ROOT)/services/boards/$(BOARD) \
 			-I$(KERNEL_ROOT)/services/app
 
-board: libserial.o usyscall.o test_irq_sender.o
+board: libserial.o arch_usyscall.o test_irq_sender.o
 	@mv $^ ../../app
 
 %.o: %.c
diff --git a/Ubiquitous/XiZi_AIoT/services/boards/zynq7000-zc702/libserial.h b/Ubiquitous/XiZi_AIoT/services/boards/imx6q-sabrelite/arch_usyscall.c
similarity index 53%
rename from Ubiquitous/XiZi_AIoT/services/boards/zynq7000-zc702/libserial.h
rename to Ubiquitous/XiZi_AIoT/services/boards/imx6q-sabrelite/arch_usyscall.c
index 02d3e18af..76125fa0e 100644
--- a/Ubiquitous/XiZi_AIoT/services/boards/zynq7000-zc702/libserial.h
+++ b/Ubiquitous/XiZi_AIoT/services/boards/imx6q-sabrelite/arch_usyscall.c
@@ -9,10 +9,25 @@
  * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
  * See the Mulan PSL v2 for more details.
  */
+#include "usyscall.h"
 
-/// this file is only used for debug
-#pragma once
+int syscall(int sys_num, intptr_t a1, intptr_t a2, intptr_t a3, intptr_t a4)
+{
+    int ret = -1;
 
-void printf(char* fmt, ...);
+    __asm__ volatile(
+        "mov r0, %1;\
+        mov r1, %2;\
+        mov r2, %3;\
+        mov r3, %4;\
+        mov r4, %5;\
+        swi 0;\
+        dsb;\
+        isb;\
+        mov %0, r0"
+        : "=r"(ret)
+        : "r"(sys_num), "r"(a1), "r"(a2), "r"(a3), "r"(a4)
+        : "memory", "r0", "r1", "r2", "r3", "r4");
 
-char getc();
\ No newline at end of file
+    return ret;
+}
\ No newline at end of file
diff --git a/Ubiquitous/XiZi_AIoT/services/boards/zynq7000-zc702/Makefile b/Ubiquitous/XiZi_AIoT/services/boards/zynq7000-zc702/Makefile
index aa1013cfa..b5ada4070 100644
--- a/Ubiquitous/XiZi_AIoT/services/boards/zynq7000-zc702/Makefile
+++ b/Ubiquitous/XiZi_AIoT/services/boards/zynq7000-zc702/Makefile
@@ -19,10 +19,12 @@ INC_DIR = 	-I$(KERNEL_ROOT)/services/fs/libfs \
 			-I$(KERNEL_ROOT)/services/fs/fs_server/include \
 			-I$(KERNEL_ROOT)/services/lib/ipc \
 		  	-I$(KERNEL_ROOT)/services/lib/memory \
+			-I$(KERNEL_ROOT)/services/lib/serial \
+			-I$(KERNEL_ROOT)/services/lib/usyscall \
 			-I$(KERNEL_ROOT)/services/boards/$(BOARD) \
 			-I$(KERNEL_ROOT)/services/app
 
-board: libserial.o stub.o usyscall.o
+board: libserial.o stub.o arch_usyscall.o
 	@mv $^ ../../app
 
 %.o: %.c
diff --git a/Ubiquitous/XiZi_AIoT/services/boards/zynq7000-zc702/arch_usyscall.c b/Ubiquitous/XiZi_AIoT/services/boards/zynq7000-zc702/arch_usyscall.c
new file mode 100644
index 000000000..b3c79aafc
--- /dev/null
+++ b/Ubiquitous/XiZi_AIoT/services/boards/zynq7000-zc702/arch_usyscall.c
@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2020 AIIT XUOS Lab
+ * XiUOS is licensed under Mulan PSL v2.
+ * You can use this software according to the terms and conditions of the Mulan PSL v2.
+ * You may obtain a copy of Mulan PSL v2 at:
+ *        http://license.coscl.org.cn/MulanPSL2
+ * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
+ * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
+ * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
+ * See the Mulan PSL v2 for more details.
+ */
+#include "usyscall.h"
+
+int syscall(int sys_num, intptr_t a1, intptr_t a2, intptr_t a3, intptr_t a4)
+{
+    int ret = -1;
+
+    __asm__ volatile(
+        "mov r0, %1;\
+        mov r1, %2;\
+        mov r2, %3;\
+        mov r3, %4;\
+        mov r4, %5;\
+        swi 0;\
+        dsb;\
+        isb;\
+        mov %0, r0"
+        : "=r"(ret)
+        : "r"(sys_num), "r"(a1), "r"(a2), "r"(a3), "r"(a4)
+        : "memory", "r0", "r1", "r2", "r3", "r4");
+
+    return ret;
+}
diff --git a/Ubiquitous/XiZi_AIoT/services/boards/zynq7000-zc702/usyscall.c b/Ubiquitous/XiZi_AIoT/services/boards/zynq7000-zc702/usyscall.c
deleted file mode 100644
index c1b49a489..000000000
--- a/Ubiquitous/XiZi_AIoT/services/boards/zynq7000-zc702/usyscall.c
+++ /dev/null
@@ -1,124 +0,0 @@
-/*
- * Copyright (c) 2020 AIIT XUOS Lab
- * XiUOS is licensed under Mulan PSL v2.
- * You can use this software according to the terms and conditions of the Mulan PSL v2.
- * You may obtain a copy of Mulan PSL v2 at:
- *        http://license.coscl.org.cn/MulanPSL2
- * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
- * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
- * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
- * See the Mulan PSL v2 for more details.
- */
-#include "usyscall.h"
-#include "libmem.h"
-
-static int
-syscall(int sys_num, intptr_t a1, intptr_t a2, intptr_t a3, intptr_t a4)
-{
-    int ret = -1;
-
-    __asm__ volatile(
-        "mov r0, %1;\
-        mov r1, %2;\
-        mov r2, %3;\
-        mov r3, %4;\
-        mov r4, %5;\
-        swi 0;\
-        dsb;\
-        isb;\
-        mov %0, r0"
-        : "=r"(ret)
-        : "r"(sys_num), "r"(a1), "r"(a2), "r"(a3), "r"(a4)
-        : "memory", "r0", "r1", "r2", "r3", "r4");
-
-    return ret;
-}
-
-int spawn(struct Session* session, int fd, ipc_read_fn ipc_read, ipc_fsize_fn ipc_fsize, char* name, char** argv)
-{
-    int file_size = ipc_fsize(session, fd);
-    void* img = malloc(file_size);
-    int read_len = 0, cur_read_len = 0;
-    while (read_len < file_size) {
-        cur_read_len = file_size - read_len < 4096 ? file_size - read_len : 4096;
-        read_len += ipc_read(session, fd, img + read_len, read_len, cur_read_len);
-    }
-    int ret = syscall(SYSCALL_SPAWN, (intptr_t)img, (intptr_t)name, (intptr_t)argv, 0);
-    free(img);
-    return ret;
-}
-
-int exit()
-{
-    return syscall(SYSCALL_EXIT, 0, 0, 0, 0);
-}
-
-int yield(task_yield_reason reason)
-{
-    return syscall(SYSCALL_YIELD, (uintptr_t)reason, 0, 0, 0);
-}
-
-int kill(int pid)
-{
-    return syscall(SYSCALL_KILL, (intptr_t)pid, 0, 0, 0);
-}
-
-int register_server(char* name)
-{
-    return syscall(SYSCALL_SERVER, (intptr_t)name, 0, 0, 0);
-}
-
-int session(char* path, int capacity, struct Session* user_session)
-{
-    return syscall(SYSCALL_SESSION, (intptr_t)path, (intptr_t)capacity, (intptr_t)user_session, 0);
-}
-
-int poll_session(struct Session* userland_session_arr, int arr_capacity)
-{
-    return syscall(SYSCALL_POLL_SESSION, (intptr_t)userland_session_arr, (intptr_t)arr_capacity, 0, 0);
-}
-
-int close_session(struct Session* session)
-{
-    return syscall(SYSCALL_CLOSE_SESSION, (intptr_t)session, 0, 0, 0);
-}
-
-int get_memblock_info(sys_state_info* info)
-{
-    return syscall(SYSCALL_SYS_STATE, SYS_STATE_MEMBLOCK_INFO, (intptr_t)info, 0, 0);
-}
-
-int set_priority(sys_state_info* info)
-{
-    return syscall(SYSCALL_SYS_STATE, SYS_STATE_SET_TASK_PRIORITY, (intptr_t)info, 0, 0);
-}
-
-int task_heap_base()
-{
-    return syscall(SYSCALL_SYS_STATE, SYS_STATE_GET_HEAP_BASE, 0, 0, 0);
-}
-
-int show_task()
-{
-    return syscall(SYSCALL_SYS_STATE, SYS_STATE_SHOW_TASKS, 0, 0, 0);
-}
-
-int show_mem()
-{
-    return syscall(SYSCALL_SYS_STATE, SYS_STATE_SHOW_MEM_INFO, 0, 0, 0);
-}
-
-int show_cpu()
-{
-    return syscall(SYSCALL_SYS_STATE, SYS_STATE_SHOW_CPU_INFO, 0, 0, 0);
-}
-
-int mmap(uintptr_t vaddr, uintptr_t paddr, int len, bool is_dev)
-{
-    return syscall(SYSCALL_MMAP, vaddr, paddr, (intptr_t)len, (intptr_t)is_dev);
-}
-
-int register_irq(int irq, int opcode)
-{
-    return syscall(SYSCALL_REGISTER_IRQ, (intptr_t)irq, (intptr_t)opcode, 0, 0);
-}
\ No newline at end of file
diff --git a/Ubiquitous/XiZi_AIoT/services/boards/zynq7000-zc702/usyscall.h b/Ubiquitous/XiZi_AIoT/services/boards/zynq7000-zc702/usyscall.h
deleted file mode 100644
index e1b9b7273..000000000
--- a/Ubiquitous/XiZi_AIoT/services/boards/zynq7000-zc702/usyscall.h
+++ /dev/null
@@ -1,80 +0,0 @@
-/*
- * Copyright (c) 2020 AIIT XUOS Lab
- * XiUOS is licensed under Mulan PSL v2.
- * You can use this software according to the terms and conditions of the Mulan PSL v2.
- * You may obtain a copy of Mulan PSL v2 at:
- *        http://license.coscl.org.cn/MulanPSL2
- * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
- * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
- * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
- * See the Mulan PSL v2 for more details.
- */
-#pragma once
-#include <stdint.h>
-
-#include "libserial.h"
-#include "session.h"
-
-// clang-format off
-#define SYSCALL_TEST            0
-#define SYSCALL_SPAWN           1   // generate a brand new task to run elf
-#define SYSCALL_EXIT            2   // exit task, delete the task cb
-#define SYSCALL_YIELD           3   // yield task, go to scheduler
-
-#define SYSCALL_MMAP            4   // map a virt page to phy page
-#define SYSCALL_SERVER          5   // register current task as a server
-#define SYSCALL_SESSION         6   // create a session to a server
-#define SYSCALL_POLL_SESSION    7   // server poll for it's server sessions
-#define SYSCALL_CLOSE_SESSION   8   // client close it's client sessions
-
-#define SYSCALL_EXEC            9   // run elf using current task
-#define SYSCALL_SYS_STATE       10  // run system state
-#define SYSCALL_REGISTER_IRQ    11  //
-
-#define SYSCALL_KILL            12  // kill the task by id
-// clang-format on
-
-typedef enum {
-    SYS_STATE_TEST = 0,
-    SYS_STATE_SET_TASK_PRIORITY,
-    SYS_STATE_GET_HEAP_BASE,
-    SYS_STATE_MEMBLOCK_INFO,
-    SYS_STATE_SHOW_TASKS,
-    SYS_STATE_SHOW_MEM_INFO,
-    SYS_STATE_SHOW_CPU_INFO,
-} sys_state_option;
-
-typedef enum {
-    SYS_TASK_YIELD_NO_REASON = 0x0,
-    SYS_TASK_YIELD_FOREVER = 0x1,
-    SYS_TASK_YIELD_BLOCK_IPC = 0x2,
-} task_yield_reason;
-
-typedef union {
-    struct {
-        uintptr_t memblock_start;
-        uintptr_t memblock_end;
-    } memblock_info;
-    int priority;
-} sys_state_info;
-
-typedef int (*ipc_read_fn)(struct Session* session, int fd, char* dst, int offset, int len);
-typedef int (*ipc_fsize_fn)(struct Session* session, int fd);
-typedef int (*ipc_write_fn)(struct Session* session, int fd, char* src, int offset, int len);
-
-int spawn(struct Session* session, int fd, ipc_read_fn ipc_read, ipc_fsize_fn ipc_fsize, char* name, char** argv);
-int exit();
-int yield(task_yield_reason reason);
-int kill(int pid);
-int register_server(char* name);
-int session(char* path, int capacity, struct Session* user_session);
-int poll_session(struct Session* userland_session_arr, int arr_capacity);
-int close_session(struct Session* session);
-int task_heap_base();
-int get_memblock_info(sys_state_info* info);
-int set_priority(sys_state_info* info);
-int show_task();
-int show_mem();
-int show_cpu();
-int mmap(uintptr_t vaddr, uintptr_t paddr, int len, bool is_dev);
-int register_irq(int irq, int opcode);
\ No newline at end of file
diff --git a/Ubiquitous/XiZi_AIoT/services/fs/fs_server/Makefile b/Ubiquitous/XiZi_AIoT/services/fs/fs_server/Makefile
index e93df4cb0..5b550eb1a 100644
--- a/Ubiquitous/XiZi_AIoT/services/fs/fs_server/Makefile
+++ b/Ubiquitous/XiZi_AIoT/services/fs/fs_server/Makefile
@@ -19,6 +19,8 @@ INC_DIR = 	-I$(KERNEL_ROOT)/services/fs/libfs \
 			-I$(KERNEL_ROOT)/services/fs/fs_server/include \
 			-I$(KERNEL_ROOT)/services/lib/ipc \
 		  	-I$(KERNEL_ROOT)/services/lib/memory \
+			-I$(KERNEL_ROOT)/services/lib/serial \
+			-I$(KERNEL_ROOT)/services/lib/usyscall \
 			-I$(KERNEL_ROOT)/services/boards/$(BOARD) \
 			-I$(KERNEL_ROOT)/services/app
 
diff --git a/Ubiquitous/XiZi_AIoT/services/fs/libfs/Makefile b/Ubiquitous/XiZi_AIoT/services/fs/libfs/Makefile
index 336120483..46aad9a4c 100644
--- a/Ubiquitous/XiZi_AIoT/services/fs/libfs/Makefile
+++ b/Ubiquitous/XiZi_AIoT/services/fs/libfs/Makefile
@@ -18,6 +18,8 @@ c_useropts = -O0
 INC_DIR = 	-I$(KERNEL_ROOT)/services/fs/libfs \
 			-I$(KERNEL_ROOT)/services/lib/ipc \
 		  	-I$(KERNEL_ROOT)/services/lib/memory \
+			-I$(KERNEL_ROOT)/services/lib/serial \
+			-I$(KERNEL_ROOT)/services/lib/usyscall \
 			-I$(KERNEL_ROOT)/services/boards/$(BOARD) \
 			-I$(KERNEL_ROOT)/services/app
 
diff --git a/Ubiquitous/XiZi_AIoT/services/lib/Makefile b/Ubiquitous/XiZi_AIoT/services/lib/Makefile
index c242de34a..db124194e 100644
--- a/Ubiquitous/XiZi_AIoT/services/lib/Makefile
+++ b/Ubiquitous/XiZi_AIoT/services/lib/Makefile
@@ -1,4 +1,4 @@
-SRC_DIR := ipc memory
+SRC_DIR := ipc memory usyscall
 
 include $(KERNEL_ROOT)/compiler.mk
 
diff --git a/Ubiquitous/XiZi_AIoT/services/lib/ipc/Makefile b/Ubiquitous/XiZi_AIoT/services/lib/ipc/Makefile
index 48b6ef330..0ecba7c2e 100644
--- a/Ubiquitous/XiZi_AIoT/services/lib/ipc/Makefile
+++ b/Ubiquitous/XiZi_AIoT/services/lib/ipc/Makefile
@@ -17,6 +17,8 @@ c_useropts = -O0
 
 INC_DIR = 	-I$(KERNEL_ROOT)/services/lib/ipc \
 		  	-I$(KERNEL_ROOT)/services/lib/memory \
+			-I$(KERNEL_ROOT)/services/lib/serial \
+			-I$(KERNEL_ROOT)/services/lib/usyscall \
 			-I$(KERNEL_ROOT)/services/boards/$(BOARD) \
 			-I$(KERNEL_ROOT)/services/app
 
diff --git a/Ubiquitous/XiZi_AIoT/services/lib/memory/Makefile b/Ubiquitous/XiZi_AIoT/services/lib/memory/Makefile
index 54139e413..ceaccc4ca 100644
--- a/Ubiquitous/XiZi_AIoT/services/lib/memory/Makefile
+++ b/Ubiquitous/XiZi_AIoT/services/lib/memory/Makefile
@@ -16,6 +16,8 @@ INC_DIR = 	-I$(KERNEL_ROOT)/services/app \
 			-I$(KERNEL_ROOT)/services/fs/libfs \
 		  	-I$(KERNEL_ROOT)/services/boards/$(BOARD) \
 		  	-I$(KERNEL_ROOT)/services/lib/memory \
+			-I$(KERNEL_ROOT)/services/lib/serial \
+			-I$(KERNEL_ROOT)/services/lib/usyscall \
 		  	-I$(KERNEL_ROOT)/services/lib/ipc 
 
 all: libmem.o
diff --git a/Ubiquitous/XiZi_AIoT/services/boards/imx6q-sabrelite/libserial.h b/Ubiquitous/XiZi_AIoT/services/lib/serial/libserial.h
similarity index 100%
rename from Ubiquitous/XiZi_AIoT/services/boards/imx6q-sabrelite/libserial.h
rename to Ubiquitous/XiZi_AIoT/services/lib/serial/libserial.h
diff --git a/Ubiquitous/XiZi_AIoT/services/lib/usyscall/Makefile b/Ubiquitous/XiZi_AIoT/services/lib/usyscall/Makefile
new file mode 100644
index 000000000..d8e0c7ab5
--- /dev/null
+++ b/Ubiquitous/XiZi_AIoT/services/lib/usyscall/Makefile
@@ -0,0 +1,28 @@
+ifeq ($(BOARD), imx6q-sabrelite)
+toolchain ?= arm-none-eabi-
+endif
+ifeq ($(BOARD), zynq7000-zc702)
+toolchain ?= arm-xilinx-eabi-
+endif
+cc = ${toolchain}gcc
+ld = ${toolchain}g++
+objdump = ${toolchain}objdump
+user_ldflags = -N -Ttext 0
+
+cflags = -std=c11 -march=armv7-a -mtune=cortex-a9 -nostdlib -nodefaultlibs -mfloat-abi=soft -fno-pic -static -fno-builtin -fno-strict-aliasing -Wall -ggdb -Wno-unused -Werror -fno-omit-frame-pointer -fno-stack-protector -fno-pie 
+c_useropts = -O0
+
+INC_DIR = 	-I$(KERNEL_ROOT)/services/app \
+			-I$(KERNEL_ROOT)/services/fs/libfs \
+		  	-I$(KERNEL_ROOT)/services/boards/$(BOARD) \
+		  	-I$(KERNEL_ROOT)/services/lib/memory \
+			-I$(KERNEL_ROOT)/services/lib/serial \
+			-I$(KERNEL_ROOT)/services/lib/usyscall \
+		  	-I$(KERNEL_ROOT)/services/lib/ipc 
+
+all: usyscall.o
+	@mv $^ ../../app
+
+%.o: %.c
+	@echo "cc $^"
+	@${cc} ${cflags} ${c_useropts} ${INC_DIR} -o $@ -c $^
\ No newline at end of file
diff --git a/Ubiquitous/XiZi_AIoT/services/boards/imx6q-sabrelite/usyscall.c b/Ubiquitous/XiZi_AIoT/services/lib/usyscall/usyscall.c
similarity index 86%
rename from Ubiquitous/XiZi_AIoT/services/boards/imx6q-sabrelite/usyscall.c
rename to Ubiquitous/XiZi_AIoT/services/lib/usyscall/usyscall.c
index c1b49a489..8570c0f98 100644
--- a/Ubiquitous/XiZi_AIoT/services/boards/imx6q-sabrelite/usyscall.c
+++ b/Ubiquitous/XiZi_AIoT/services/lib/usyscall/usyscall.c
@@ -12,28 +12,6 @@
 #include "usyscall.h"
 #include "libmem.h"
 
-static int
-syscall(int sys_num, intptr_t a1, intptr_t a2, intptr_t a3, intptr_t a4)
-{
-    int ret = -1;
-
-    __asm__ volatile(
-        "mov r0, %1;\
-        mov r1, %2;\
-        mov r2, %3;\
-        mov r3, %4;\
-        mov r4, %5;\
-        swi 0;\
-        dsb;\
-        isb;\
-        mov %0, r0"
-        : "=r"(ret)
-        : "r"(sys_num), "r"(a1), "r"(a2), "r"(a3), "r"(a4)
-        : "memory", "r0", "r1", "r2", "r3", "r4");
-
-    return ret;
-}
-
 int spawn(struct Session* session, int fd, ipc_read_fn ipc_read, ipc_fsize_fn ipc_fsize, char* name, char** argv)
 {
     int file_size = ipc_fsize(session, fd);
diff --git a/Ubiquitous/XiZi_AIoT/services/boards/imx6q-sabrelite/usyscall.h b/Ubiquitous/XiZi_AIoT/services/lib/usyscall/usyscall.h
similarity index 97%
rename from Ubiquitous/XiZi_AIoT/services/boards/imx6q-sabrelite/usyscall.h
rename to Ubiquitous/XiZi_AIoT/services/lib/usyscall/usyscall.h
index e1b9b7273..822831942 100644
--- a/Ubiquitous/XiZi_AIoT/services/boards/imx6q-sabrelite/usyscall.h
+++ b/Ubiquitous/XiZi_AIoT/services/lib/usyscall/usyscall.h
@@ -62,6 +62,8 @@ typedef int (*ipc_read_fn)(struct Session* session, int fd, char* dst, int offse
 typedef int (*ipc_fsize_fn)(struct Session* session, int fd);
 typedef int (*ipc_write_fn)(struct Session* session, int fd, char* src, int offset, int len);
 
+int syscall(int sys_num, intptr_t a1, intptr_t a2, intptr_t a3, intptr_t a4);
+
 int spawn(struct Session* session, int fd, ipc_read_fn ipc_read, ipc_fsize_fn ipc_fsize, char* name, char** argv);
 int exit();
 int yield(task_yield_reason reason);
diff --git a/Ubiquitous/XiZi_AIoT/services/shell/letter-shell/Makefile b/Ubiquitous/XiZi_AIoT/services/shell/letter-shell/Makefile
index e2bdb095e..3caddc340 100644
--- a/Ubiquitous/XiZi_AIoT/services/shell/letter-shell/Makefile
+++ b/Ubiquitous/XiZi_AIoT/services/shell/letter-shell/Makefile
@@ -18,6 +18,8 @@ c_useropts = -O0
 INC_DIR = 	-I$(KERNEL_ROOT)/services/app \
 			-I$(KERNEL_ROOT)/services/fs/libfs \
 		  	-I$(KERNEL_ROOT)/services/lib/memory \
+			-I$(KERNEL_ROOT)/services/lib/serial \
+			-I$(KERNEL_ROOT)/services/lib/usyscall \
 			-I$(KERNEL_ROOT)/services/lib/ipc \
 			-I$(KERNEL_ROOT)/services/boards/$(BOARD) 
 
diff --git a/Ubiquitous/XiZi_AIoT/softkernel/trap/default_irq_handler.c b/Ubiquitous/XiZi_AIoT/softkernel/trap/default_irq_handler.c
index c20bcc100..a475c0810 100644
--- a/Ubiquitous/XiZi_AIoT/softkernel/trap/default_irq_handler.c
+++ b/Ubiquitous/XiZi_AIoT/softkernel/trap/default_irq_handler.c
@@ -46,11 +46,11 @@ bool intr_distributer_init(struct IrqDispatcherRightGroup* _right_group)
     return p_intr_driver != NULL;
 }
 
-void default_interrupt_routine(void)
+void default_interrupt_routine(int irq)
 {
     /* default handler borrow the rights of dispatcher */
     ///@todo Support other cores. (currently assume that CPU_0 is used)
-    ERROR("Interrupt %d has been asserted\n", p_intr_driver->curr_int[0]);
+    ERROR("Interrupt %d has been asserted\n", irq);
 }
 
 extern void context_switch(struct context**, struct context*);
@@ -69,20 +69,19 @@ void intr_irq_dispatch(struct trapframe* tf)
     assert(current_task != NULL);
     current_task->main_thread.trapframe = tf;
 
-    unsigned cpu = p_intr_driver->hw_cur_int_cpu(int_info);
+    int cpu = cur_cpuid();
+    assert(cpu >= 0 && cpu < NR_CPU);
     unsigned irq = p_intr_driver->hw_cur_int_num(int_info);
-    p_intr_driver->curr_int[cpu] = irq;
 
     // distribute irq
     irq_handler_t isr = p_intr_driver->sw_irqtbl[irq].handler;
     if (isr != NULL) {
         isr(irq, tf, NULL);
     } else {
-        default_interrupt_routine();
+        default_interrupt_routine(irq);
     }
 
     // finish irq.
-    p_intr_driver->curr_int[cpu] = 0;
     p_intr_driver->hw_after_irq(int_info);
 
     if (cur_cpu()->task == NULL || current_task->state != RUNNING) {