想改启动参数"androidboot.console=s3c2410_serial3"无效

smart210 烧写android 2.3。然户不使用s3c2410_serial0 作为命令行控制端，改用s3c2410_serial3。
但是修改了参数以后没有反应，不能输入命令。

s3c2410_serial3 只引出了TX,RX,GND。

还有，如果把启动参数的“console”也改马ttySAC3的话。刚开始能看到内核的日志。但是启动到申请串口中断就不能继续启动了。
日志如下：
[    3.650294] ThumbEE CPU extension supported.                                
[    3.654646] VFP support v0.3: implementor 41 architecture 3 part 30 variant 2
[    3.662536] regulator_init_complete: disabling pd_mfc_supply                
[    3.667814] regulator_init_complete: disabling pd_tv_supply                  
[    3.673345] regulator_init_complete: disabling pd_cam_supply                
[    3.679035] smdkc110-rtc smdkc110-rtc: setting system clock to 2012-01-01 12)
[    3.688137] request_irq(101,XXX,0x20,s3c-fimc0,0xdff14000)                  
[    3.694769] FIMC0 registered successfully                                    
[    3.697521] request_irq(102,XXX,0x20,s3c-fimc1,0xdff14194)                  
[    3.704071] FIMC1 registered successfully                                    
[    3.706956] request_irq(103,XXX,0x20,s3c-fimc2,0xdff14328)                  
[    3.713541] FIMC2 registered successfully                                    
[    3.716383] <6>S5PC1XX TVOUT Driver, (c) 2009 Samsung Electronics            
[    3.723059] s5p-tvout s5p-tvout: hpd status is cable removed                
[    3.728028] request_irq(107,XXX,0x20,s5p-tvout,0xc069cfb8)                  
[    3.733499] request_irq(108,XXX,0x20,s5p-tvout,0xc069cfb8)                  
[    3.738950] request_irq(111,XXX,0x20,s5p-tvout,0xc069cfb8)                  
[    3.750324] request_irq(28,XXX,0x0,s5pv210-uart,0xc06c02ec)                  
[    3.754449] request_irq(30,XXX,0x0,s5pv210-ua
在上面这个位置输出到s5pv210-ua就死掉了。

所以现在的启动参数设成：
Android-CommandLine = root=/dev/mtdblock4 rootfstype=yaffs2 console=ttySAC0,115200 init=/linuxrc androidboot.console=s3c2410_serial3

可以在串口0中看到内核输出的日志 ，但是不能在串口3中输入命令。

修改内核选项   System Type  --->   (0) S3C UART to use for low-level messages  改成  (3) S3C UART to use for low-level messages 试一下