diff --git a/Ubiquitous/XiZi_AIoT/hardkernel/mmu/arm/armv8-a/cortex-a55/bootmmu.c b/Ubiquitous/XiZi_AIoT/hardkernel/mmu/arm/armv8-a/cortex-a55/bootmmu.c
index f05989867..78b665e8e 100644
--- a/Ubiquitous/XiZi_AIoT/hardkernel/mmu/arm/armv8-a/cortex-a55/bootmmu.c
+++ b/Ubiquitous/XiZi_AIoT/hardkernel/mmu/arm/armv8-a/cortex-a55/bootmmu.c
@@ -122,89 +122,6 @@ static void build_boot_pgdir()
 }
 
 #include "log.h"
-#include "ns16550.h"
-#define UART_LCRVAL UART_LCR_8N1 /* 8 data, 1 stop, no parity */
-#define UART_MCRVAL (UART_MCR_DTR | UART_MCR_RTS) /* RTS/DTR */
-
-#define out_le32(a, v) (*(volatile uint32_t*)(a) = (v))
-#define in_le32(a) (*(volatile uint32_t*)(a))
-
-#ifndef CONFIG_SYS_NS16550_IER
-#define CONFIG_SYS_NS16550_IER 0x00
-#endif /* CONFIG_SYS_NS16550_IER */
-
-#define serial_dout(reg, value)                                                   \
-    serial_out_shift((char*)com_port + ((char*)reg - (char*)com_port) * (1 << 2), \
-        2, value)
-#define serial_din(reg)                                                          \
-    serial_in_shift((char*)com_port + ((char*)reg - (char*)com_port) * (1 << 2), \
-        2)
-
-#define DIV_ROUND_CLOSEST(x, divisor) (                                                                                                      \
-    {                                                                                                                                        \
-        typeof(x) __x = x;                                                                                                                   \
-        typeof(divisor) __d = divisor;                                                                                                       \
-        (((typeof(x))-1) > 0 || ((typeof(divisor))-1) > 0 || (__x) > 0) ? (((__x) + ((__d) / 2)) / (__d)) : (((__x) - ((__d) / 2)) / (__d)); \
-    })
-
-int _ns16550_calc_divisor(NS16550_t port, int clock, int baudrate)
-{
-    const unsigned int mode_x_div = 16;
-
-    return DIV_ROUND_CLOSEST(clock, mode_x_div * baudrate);
-}
-static inline void serial_out_shift(void* addr, int shift, int value)
-{
-    out_le32(addr, value);
-}
-
-static inline int serial_in_shift(void* addr, int shift)
-{
-    return in_le32(addr);
-}
-
-void __debug_uart_init(void)
-{
-    struct NS16550* com_port = (struct NS16550*)0xFE660000ULL;
-
-    /*
-     * We copy the code from above because it is already horribly messy.
-     * Trying to refactor to nicely remove the duplication doesn't seem
-     * feasible. The better fix is to move all users of this driver to
-     * driver model.
-     */
-    int baud_divisor = _ns16550_calc_divisor(com_port, 24000000,
-        1500000);
-    serial_dout(&com_port->ier, CONFIG_SYS_NS16550_IER);
-    serial_dout(&com_port->mcr, UART_MCRVAL);
-    serial_dout(&com_port->fcr, UART_FCR_DEFVAL);
-
-    serial_dout(&com_port->lcr, UART_LCR_BKSE | UART_LCRVAL);
-    serial_dout(&com_port->dll, baud_divisor & 0xff);
-    serial_dout(&com_port->dlm, (baud_divisor >> 8) & 0xff);
-    serial_dout(&com_port->lcr, UART_LCRVAL);
-}
-
-void __debug_uart_putc(int ch)
-{
-    static struct NS16550* com_port = (struct NS16550*)0xFE660000ULL;
-
-    if (ch == '\n') {
-        _debug_uart_putc('\r');
-    }
-
-    while (!(serial_din(&com_port->lsr) & UART_LSR_THRE))
-        ;
-    serial_dout(&com_port->thr, ch);
-}
-
-void __print(){
-    __debug_uart_init();
-    for(int i = 0; i < 10; i++){
-        __debug_uart_putc((int)'+');
-    }
-}
-
 static void load_boot_pgdir()
 {
 
@@ -253,11 +170,6 @@ extern void main(void);
 static bool _bss_inited = false;
 void bootmain()
 {
-    __print();
-    // if(_bss_inited){
-    //     unsigned int* p = (unsigned int*)0xffffffff;
-    //     *p = 0;
-    // }
     build_boot_pgdir();
     load_boot_pgdir();
     __asm__ __volatile__("add sp, sp, %0" ::"r"(KERN_OFFSET));