diff --git a/kernel/common/Makefile b/kernel/common/Makefile
index af3636ec..0581abfb 100644
--- a/kernel/common/Makefile
+++ b/kernel/common/Makefile
@@ -3,7 +3,7 @@ CFLAGS += -I .
 
 kernel_common_subdirs:=libELF math
 
-all: glib.o printk.o cpu.o bitree.o
+all: glib.o printk.o cpu.o bitree.o kfifo.o
 	@list='$(kernel_common_subdirs)'; for subdir in $$list; do \
     		echo "make all in $$subdir";\
     		cd $$subdir;\
@@ -21,4 +21,7 @@ cpu.o: cpu.c
 	gcc $(CFLAGS) -c cpu.c -o cpu.o
 
 bitree.o: bitree.c
-	gcc $(CFLAGS) -c bitree.c -o bitree.o
\ No newline at end of file
+	gcc $(CFLAGS) -c bitree.c -o bitree.o
+
+kfifo.o: kfifo.c
+	gcc $(CFLAGS) -c kfifo.c -o kfifo.o
diff --git a/kernel/common/kfifo.c b/kernel/common/kfifo.c
new file mode 100644
index 00000000..18d08470
--- /dev/null
+++ b/kernel/common/kfifo.c
@@ -0,0 +1,151 @@
+#include <common/kfifo.h>
+#include <common/glib.h>
+#include <common/errno.h>
+#include <common/compiler.h>
+#include <mm/slab.h>
+
+/**
+ * @brief 通过动态方式初始化kfifo缓冲队列
+ *
+ * @param fifo 队列结构体
+ * @param size 缓冲区大小
+ * @param reserved 暂时保留，请置为0
+ * @return int 错误码：成功->0
+ */
+int kfifo_alloc(struct kfifo_t *fifo, uint32_t size, uint64_t reserved)
+{
+    memset(fifo, 0, sizeof(struct kfifo_t));
+    fifo->buffer = kmalloc(size, 0);
+    if (fifo->buffer == NULL)
+        goto failed;
+
+    fifo->total_size = size;
+    return 0;
+failed:;
+    return -ENOMEM;
+}
+
+/**
+ * @brief 使用指定的缓冲区来初始化kfifo缓冲队列
+ *
+ * @param fifo 队列结构体
+ * @param buffer 缓冲区
+ * @param size 缓冲区大小
+ */
+void kfifo_init(struct kfifo_t *fifo, void *buffer, uint32_t size)
+{
+    memset(fifo, 0, sizeof(struct kfifo_t));
+
+    fifo->buffer = buffer;
+    fifo->total_size = size;
+}
+
+/**
+ * @brief 向kfifo缓冲区推入数据
+ *
+ * @param fifo 队列结构体
+ * @param from 来源数据地址
+ * @param size 数据大小（字节数）
+ * @return uint32_t 推入的数据大小
+ */
+uint32_t kfifo_in(struct kfifo_t *fifo, const void *from, uint32_t size)
+{
+    // 判断空间是否够
+    if (unlikely(fifo->size + size > fifo->total_size))
+        return 0;
+    if (unlikely(from == NULL))
+        return 0;
+
+    // 分两种情况，一种是要发生回环，另一种不发生回环
+    if (fifo->in_offset + size > fifo->total_size) // 发生回环
+    {
+        uint32_t tmp = fifo->total_size - fifo->in_offset;
+        memcpy(fifo->buffer + fifo->in_offset, from, tmp);
+        memcpy(fifo->buffer, from + tmp, size - tmp);
+        fifo->in_offset = size - tmp;
+    }
+    else // 不发生回环
+    {
+        memcpy(fifo->buffer + fifo->in_offset, from, size);
+        fifo->in_offset += size;
+    }
+
+    fifo->size += size;
+
+    return size;
+}
+
+/**
+ * @brief 从kfifo缓冲区取出数据，并从队列中删除数据
+ *
+ * @param fifo 队列结构体
+ * @param to 拷贝目标地址
+ * @param size 数据大小（字节数）
+ * @return uint32_t 取出的数据大小
+ */
+uint32_t kfifo_out(struct kfifo_t *fifo, void *to, uint32_t size)
+{
+    if (unlikely(to == NULL)) // 判断目标地址是否为空
+        return 0;
+    if (unlikely(size > fifo->size)) // 判断队列中是否有这么多数据
+        return 0;
+
+    // 判断是否会发生回环
+    if (fifo->out_offset + size > fifo->total_size) // 发生回环
+    {
+        uint32_t tmp = fifo->total_size - fifo->out_offset;
+        memcpy(to, fifo->buffer + fifo->out_offset, tmp);
+        memcpy(to + tmp, fifo->buffer, size - tmp);
+        fifo->out_offset = size - tmp;
+    }
+    else // 未发生回环
+    {
+        memcpy(to, fifo->buffer + fifo->out_offset, size);
+        fifo->out_offset += size;
+    }
+
+    fifo->size -= size;
+
+    return size;
+}
+
+/**
+ * @brief 从kfifo缓冲区取出数据，但是不从队列中删除数据
+ *
+ * @param fifo 队列结构体
+ * @param to 拷贝目标地址
+ * @param size 数据大小（字节数）
+ * @return uint32_t 取出的数据大小
+ */
+uint32_t kfifo_out_peek(struct kfifo_t *fifo, void *to, uint32_t size)
+{
+    if (unlikely(to == NULL)) // 判断目标地址是否为空
+        return 0;
+    if (unlikely(size > fifo->size)) // 判断队列中是否有这么多数据
+        return 0;
+
+    // 判断是否会发生回环
+    if (fifo->out_offset + size > fifo->total_size) // 发生回环
+    {
+        uint32_t tmp = fifo->total_size - fifo->out_offset;
+        memcpy(to, fifo->buffer + fifo->out_offset, tmp);
+        memcpy(to + tmp, fifo->buffer, size - tmp);
+    }
+    else // 未发生回环
+    {
+        memcpy(to, fifo->buffer + fifo->out_offset, size);
+    }
+
+    return size;
+}
+
+/**
+ * @brief 释放通过kfifo_alloc创建的fifo缓冲区
+ *
+ * @param fifo fifo队列结构体
+ */
+void kfifo_free_alloc(struct kfifo_t *fifo)
+{
+    kfree(fifo->buffer);
+    memset(fifo, 0, sizeof(struct kfifo_t));
+}
\ No newline at end of file
diff --git a/kernel/common/kfifo.h b/kernel/common/kfifo.h
new file mode 100644
index 00000000..a03dc475
--- /dev/null
+++ b/kernel/common/kfifo.h
@@ -0,0 +1,118 @@
+#pragma once
+
+#include <stdint.h>
+
+struct kfifo_t
+{
+    uint32_t total_size; // 缓冲区总空间
+    uint32_t size;       // 元素所占的字节数
+    uint32_t in_offset;  // 入口偏移
+    uint32_t out_offset; // 出口偏移
+    void *buffer;        // 缓冲区
+} __attribute__((aligned(sizeof(long))));
+
+/**
+ * @brief 忽略kfifo队列中的所有内容，并把输入和输出偏移量都归零
+ *
+ */
+#define kfifo_reset(fifo) (void)({ \
+    (fifo)->size = 0;              \
+    (fifo)->in_offset = 0;         \
+    (fifo)->out_offset = 0;        \
+})
+
+/**
+ * @brief 忽略kfifo队列中的所有内容，并使得输出偏移量为输入偏移量
+ *
+ */
+#define kfifo_reset_out(fifo) (void)({      \
+    (fifo)->size = 0;                       \
+    (fifo)->out_offset = (fifo)->in_offset; \
+})
+
+/**
+ * @brief 获取kfifo缓冲区的最大大小
+ *
+ * @param fifo 队列结构体
+ * @return uint32_t 缓冲区最大大小
+ */
+#define kfifo_total_size(fifo) ((fifo)->total_size)
+/**
+ * @brief 获取kfifo缓冲区当前已有元素大小
+ *
+ * @param fifo 队列结构体
+ * @return uint32_t 缓冲区当前已有元素大小
+ */
+#define kfifo_size(fifo) ((fifo)->size)
+
+/**
+ * @brief 判断kfifo缓冲区当前是否为空
+ *
+ * @param fifo 队列结构体
+ * @return uint32_t 0->非空， 1->空
+ */
+#define kfifo_empty(fifo) (((fifo)->size == 0) ? 1 : 0)
+
+/**
+ * @brief 判断kfifo缓冲区当前是否为满
+ *
+ * @param fifo 队列结构体
+ * @return uint32_t 0->不满， 1->满
+ */
+#define kfifo_full(fifo) (((fifo)->size == (fifo)->total_size) ? 1 : 0)
+
+/**
+ * @brief 通过动态方式初始化kfifo缓冲队列
+ *
+ * @param fifo 队列结构体
+ * @param size 缓冲区大小
+ * @param reserved 暂时保留，请置为0
+ * @return int 错误码：成功->0
+ */
+int kfifo_alloc(struct kfifo_t *fifo, uint32_t size, uint64_t reserved);
+
+/**
+ * @brief 释放通过kfifo_alloc创建的fifo缓冲区
+ * 
+ * @param fifo fifo队列结构体
+ */
+void kfifo_free_alloc(struct kfifo_t* fifo);
+
+/**
+ * @brief 使用指定的缓冲区来初始化kfifo缓冲队列
+ *
+ * @param fifo 队列结构体
+ * @param buffer 缓冲区
+ * @param size 缓冲区大小
+ */
+void kfifo_init(struct kfifo_t *fifo, void *buffer, uint32_t size);
+
+/**
+ * @brief 向kfifo缓冲区推入数据
+ *
+ * @param fifo 队列结构体
+ * @param from 来源数据地址
+ * @param size 数据大小（字节数）
+ * @return uint32_t 推入的数据大小
+ */
+uint32_t kfifo_in(struct kfifo_t *fifo, const void *from, uint32_t size);
+
+/**
+ * @brief 从kfifo缓冲区取出数据，并从队列中删除数据
+ *
+ * @param fifo 队列结构体
+ * @param to 拷贝目标地址
+ * @param size 数据大小（字节数）
+ * @return uint32_t 取出的数据大小
+ */
+uint32_t kfifo_out(struct kfifo_t *fifo, void *to, uint32_t size);
+
+/**
+ * @brief 从kfifo缓冲区取出数据，但是不从队列中删除数据
+ *
+ * @param fifo 队列结构体
+ * @param to 拷贝目标地址
+ * @param size 数据大小（字节数）
+ * @return uint32_t 取出的数据大小
+ */
+uint32_t kfifo_out_peek(struct kfifo_t *fifo, void *to, uint32_t size);
diff --git a/kernel/driver/usb/xhci/xhci.c b/kernel/driver/usb/xhci/xhci.c
index 1e13767c..7b845728 100644
--- a/kernel/driver/usb/xhci/xhci.c
+++ b/kernel/driver/usb/xhci/xhci.c
@@ -347,7 +347,7 @@ static uint32_t xhci_hc_get_protocol_offset(int id, uint32_t list_off, const int
                 *offset = (uint32_t)(dw2 & 0xff) - 1; // 使其转换为zero based
             if (count != NULL)
                 *count = (uint32_t)((dw2 & 0xff00) >> 8);
-            if (protocol_flag != NULL)
+            if (protocol_flag != NULL && version == 2)
                 *protocol_flag = (uint16_t)((dw2 >> 16) & 0x0fff);
 
             return next_list_off;
diff --git a/kernel/ktest/Makefile b/kernel/ktest/Makefile
index dce56893..ef3b8a20 100644
--- a/kernel/ktest/Makefile
+++ b/kernel/ktest/Makefile
@@ -2,7 +2,10 @@
 CFLAGS += -I .
 
 
-all: bitree.o
+all: bitree.o kfifo.o
 
 bitree.o: test-bitree.c
-	gcc $(CFLAGS) -c test-bitree.c -o test-bitree.o
\ No newline at end of file
+	gcc $(CFLAGS) -c test-bitree.c -o test-bitree.o
+
+kfifo.o: test-kfifo.c
+	gcc $(CFLAGS) -c test-kfifo.c -o test-kfifo.o
diff --git a/kernel/ktest/ktest.h b/kernel/ktest/ktest.h
index a2be05fb..86c717df 100644
--- a/kernel/ktest/ktest.h
+++ b/kernel/ktest/ktest.h
@@ -1,4 +1,5 @@
 #pragma once
 #include <common/sys/types.h>
 
-uint64_t ktest_test_bitree(uint64_t arg);
\ No newline at end of file
+uint64_t ktest_test_bitree(uint64_t arg);
+uint64_t ktest_test_kfifo(uint64_t arg);
\ No newline at end of file
diff --git a/kernel/ktest/test-bitree.c b/kernel/ktest/test-bitree.c
index 84d83a74..ef92bc09 100644
--- a/kernel/ktest/test-bitree.c
+++ b/kernel/ktest/test-bitree.c
@@ -127,6 +127,6 @@ uint64_t ktest_test_bitree(uint64_t arg)
         kTEST("Testing case %d", i);
         kt_bitree_func_table[i](0, 0);
     }
-    kdebug("bitree Test done.");
+    kTEST("bitree Test done.");
     return 0;
 }
\ No newline at end of file
diff --git a/kernel/ktest/test-kfifo.c b/kernel/ktest/test-kfifo.c
new file mode 100644
index 00000000..02834c60
--- /dev/null
+++ b/kernel/ktest/test-kfifo.c
@@ -0,0 +1,165 @@
+#include "ktest.h"
+#include "ktest_utils.h"
+#include <common/kfifo.h>
+#include <common/kprint.h>
+#include <mm/slab.h>
+
+static long ktest_kfifo_case0_1(uint64_t arg0, uint64_t arg1)
+{
+    const int fifo_size = 256;
+    // 创建kfifo（由kfifo申请内存）
+    struct kfifo_t fifo;
+    if (arg0 == 0)
+        assert(kfifo_alloc(&fifo, fifo_size, 0) == 0);
+    else
+    {
+        void *buf = kmalloc(fifo_size, 0);
+        kfifo_init(&fifo, buf, fifo_size);
+    }
+
+    assert(fifo.buffer != NULL);
+    assert(fifo.total_size == fifo_size);
+    assert(kfifo_total_size(&fifo) == fifo_size);
+    assert(fifo.size == 0);
+    assert(kfifo_size(&fifo) == 0);
+    assert(fifo.in_offset == 0);
+    assert(fifo.out_offset == 0);
+    assert(kfifo_empty(&fifo) == 1);
+    assert(kfifo_full(&fifo) == 0);
+
+    // 循环增加10个uint64_t
+    for (int i = 1; i <= 10; ++i)
+    {
+        uint64_t tmp = i;
+        assert(kfifo_in(&fifo, &tmp, sizeof(uint64_t)) == sizeof(uint64_t));
+    }
+    assert(fifo.in_offset == 10 * sizeof(uint64_t));
+    assert(fifo.out_offset == 0);
+    assert(fifo.size == 10 * sizeof(uint64_t));
+    assert(fifo.total_size == fifo_size);
+
+    // 循环删除这10个uint64_t
+    for (int i = 1; i <= 10; ++i)
+    {
+        uint64_t tmp = 0;
+        assert(kfifo_out(&fifo, &tmp, sizeof(uint64_t)) == sizeof(uint64_t));
+        assert(tmp == i);
+        assert(fifo.size == (10 - i) * sizeof(uint64_t));
+        assert(fifo.in_offset == 10 * sizeof(uint64_t));
+        assert(fifo.out_offset == i * sizeof(uint64_t));
+    }
+
+    assert(fifo.in_offset == 10 * sizeof(uint64_t));
+    assert(fifo.out_offset == 10 * sizeof(uint64_t));
+    assert(fifo.in_offset == fifo.out_offset);
+    assert(kfifo_empty(&fifo) == 1);
+
+    // reset
+    kfifo_reset(&fifo);
+    assert(fifo.in_offset == 0);
+    assert(fifo.out_offset == 0);
+    assert(fifo.size == 0);
+
+    // 测试插入31个元素
+    for (int i = 1; i <= 31; ++i)
+    {
+        uint64_t tmp = i;
+        assert(kfifo_in(&fifo, &tmp, sizeof(uint64_t)) == sizeof(uint64_t));
+    }
+
+    assert(fifo.size == 31 * sizeof(uint64_t));
+    assert(fifo.in_offset == 31 * sizeof(uint64_t));
+    assert(fifo.out_offset == 0);
+
+    // 然后再尝试插入一个大小为2*sizeof(uint64_t)的元素
+    {
+        __int128_t tmp = 100;
+        assert(kfifo_in(&fifo, &tmp, sizeof(__int128_t)) == 0);
+        assert(fifo.size == 31 * sizeof(uint64_t));
+        assert(fifo.in_offset == 31 * sizeof(uint64_t));
+        assert(fifo.out_offset == 0);
+    }
+    // 插入一个uint64, 队列满
+    {
+        uint64_t tmp = 32;
+        assert(kfifo_in(&fifo, &tmp, sizeof(uint64_t)) == sizeof(uint64_t));
+        assert(kfifo_full(&fifo));
+        assert(kfifo_empty(&fifo) == 0);
+        assert(fifo.size == fifo.total_size);
+        assert(fifo.in_offset == fifo_size);
+        assert(fifo.out_offset == 0);
+    }
+
+    // 取出之前的20个元素
+    for (int i = 1; i <= 20; ++i)
+    {
+        uint64_t tmp = 0;
+        assert(kfifo_out(&fifo, &tmp, sizeof(uint64_t)) == sizeof(uint64_t));
+    }
+    assert(fifo.size == (fifo.total_size - 20 * sizeof(uint64_t)));
+    assert(fifo.in_offset == fifo_size);
+    assert(fifo.out_offset == 20 * sizeof(uint64_t));
+
+    // 插入10个元素,剩余10个空位
+    {
+        uint64_t tmp = 99;
+
+        assert(kfifo_in(&fifo, &tmp, sizeof(uint64_t)) == sizeof(uint64_t));
+        assert(fifo.in_offset == 1 * sizeof(uint64_t));
+
+        for (int i = 1; i <= 9; ++i)
+        {
+            assert(kfifo_in(&fifo, &tmp, sizeof(uint64_t)) == sizeof(uint64_t));
+        }
+        assert(fifo.in_offset == 10 * sizeof(uint64_t));
+        assert(fifo.size == 22 * sizeof(uint64_t));
+    }
+
+    {
+        // 取出20个
+        char tmp[20 * sizeof(uint64_t)];
+        assert(kfifo_out(&fifo, &tmp, 20 * sizeof(uint64_t)) == 20 * sizeof(uint64_t));
+        assert(fifo.out_offset == 8 * sizeof(uint64_t));
+        assert(fifo.size == 2 * (sizeof(uint64_t)));
+    }
+
+    {
+        // 插入25个
+        char tmp[25 * sizeof(uint64_t)];
+        assert(kfifo_in(&fifo, &tmp, 25 * sizeof(uint64_t)) == 25 * sizeof(uint64_t));
+        assert(fifo.out_offset == 8 * sizeof(uint64_t));
+        assert(fifo.size == 27 * sizeof(uint64_t));
+        assert(fifo.in_offset == 3 * sizeof(uint64_t));
+    }
+
+    // 测试reset out
+    uint32_t prev_in_offset = fifo.in_offset;
+    kfifo_reset_out(&fifo);
+    assert(fifo.size == 0);
+    assert(fifo.total_size == fifo_size);
+    assert(fifo.in_offset == prev_in_offset);
+    assert(fifo.out_offset == prev_in_offset);
+
+    // 测试释放
+    if (arg0 == 0)
+    {
+        kfifo_free_alloc(&fifo);
+        assert(fifo.buffer == NULL);
+    }
+}
+
+static ktest_case_table kt_kfifo_func_table[] = {
+    ktest_kfifo_case0_1,
+};
+
+uint64_t ktest_test_kfifo(uint64_t arg)
+{
+    kTEST("Testing kfifo...");
+    for (int i = 0; i < sizeof(kt_kfifo_func_table) / sizeof(ktest_case_table); ++i)
+    {
+        kTEST("Testing case %d", i);
+        kt_kfifo_func_table[i](i, 0);
+    }
+    kTEST("kfifo Test done.");
+    return 0;
+}
diff --git a/kernel/process/process.c b/kernel/process/process.c
index 36bcadd9..ccd2a73f 100644
--- a/kernel/process/process.c
+++ b/kernel/process/process.c
@@ -415,8 +415,10 @@ ul initial_kernel_thread(ul arg)
     fat32_init();
     usb_init();
 
-    pid_t test_thread_pid = kernel_thread(ktest_test_bitree, 1, 0);
-    kdebug("test_thread_pid=%d", test_thread_pid);
+    // 对一些组件进行单元测试
+    kernel_thread(ktest_test_bitree, 0, 0);
+    kernel_thread(ktest_test_kfifo, 0, 0);
+
     // 准备切换到用户态
     struct pt_regs *regs;
 
@@ -644,7 +646,6 @@ unsigned long do_fork(struct pt_regs *regs, unsigned long clone_flags, unsigned
     if (process_copy_flags(clone_flags, tsk))
         goto copy_flags_failed;
 
-    kdebug("before copy mm");
     // 拷贝内存空间分布结构体
     if (process_copy_mm(clone_flags, tsk))
         goto copy_mm_failed;