linux设备驱动程序学习（3-补）-linux中的循环缓冲区 - linux设备驱动程序 - tekkaman ninja.htm

Linux设备驱动程序学习（3-补）-Linux中的循环缓冲区 - Linux设备驱动程序.rar

                                style="COLOR: #0000cc">#</SPAN>cat <SPAN 
                                style="COLOR: #0000cc">/</SPAN>proc<SPAN 
                                style="COLOR: #0000cc">/</SPAN>devices<BR>Character 
                                devices<SPAN 
                                style="COLOR: #0000cc">:</SPAN><BR>&nbsp;&nbsp;1 
                                mem<BR>&nbsp;&nbsp;2 pty<BR>&nbsp;&nbsp;3 
                                ttyp<BR>&nbsp;&nbsp;4 <SPAN 
                                style="COLOR: #0000cc">/</SPAN>dev<SPAN 
                                style="COLOR: #0000cc">/</SPAN>vc<SPAN 
                                style="COLOR: #0000cc">/</SPAN>0<BR>&nbsp;&nbsp;4 
                                tty<BR>&nbsp;&nbsp;4 ttyS<BR>&nbsp;&nbsp;5 <SPAN 
                                style="COLOR: #0000cc">/</SPAN>dev<SPAN 
                                style="COLOR: #0000cc">/</SPAN>tty<BR>&nbsp;&nbsp;5 
                                <SPAN style="COLOR: #0000cc">/</SPAN>dev<SPAN 
                                style="COLOR: #0000cc">/</SPAN>console<BR>&nbsp;&nbsp;5 
                                <SPAN style="COLOR: #0000cc">/</SPAN>dev<SPAN 
                                style="COLOR: #0000cc">/</SPAN>ptmx<BR>&nbsp;&nbsp;7 
                                vcs<BR>&nbsp;10 misc<BR>&nbsp;13 
                                input<BR>&nbsp;14 sound<BR>&nbsp;81 
                                video4linux<BR>&nbsp;89 i2c<BR>&nbsp;90 
                                mtd<BR>116 alsa<BR>128 ptm<BR>136 pts<BR>153 
                                spi<BR>180 usb<BR>189 usb_device<BR>204 
                                s3c2410_serial<BR><FONT color=#ff0000>252 
                                scull_kfifo</FONT><BR>253 usb_endpoint<BR>254 
                                rtc<BR><BR>Block devices<SPAN 
                                style="COLOR: #0000cc">:</SPAN><BR>&nbsp;&nbsp;1 
                                ramdisk<BR>256 rfd<BR>&nbsp;&nbsp;7 
                                loop<BR>&nbsp;31 mtdblock<BR>&nbsp;93 
                                nftl<BR>&nbsp;96 inftl<BR>179 mmc<BR><SPAN 
                                style="COLOR: #0000cc">[</SPAN>Tekkaman2440@SBC2440V4<SPAN 
                                style="COLOR: #0000cc">]</SPAN><SPAN 
                                style="COLOR: #0000cc">#</SPAN>mknod <SPAN 
                                style="COLOR: #0000cc">-</SPAN>m 666 <SPAN 
                                style="COLOR: #0000cc">/</SPAN>dev<SPAN 
                                style="COLOR: #0000cc">/</SPAN>scull_kfifo c 252 
                                0<BR><SPAN 
                                style="COLOR: #0000cc">[</SPAN>Tekkaman2440@SBC2440V4<SPAN 
                                style="COLOR: #0000cc">]</SPAN><SPAN 
                                style="COLOR: #0000cc">#</SPAN>echo 1234567890 
                                <SPAN style="COLOR: #0000cc">&gt;</SPAN> <SPAN 
                                style="COLOR: #0000cc">/</SPAN>dev<SPAN 
                                style="COLOR: #0000cc">/</SPAN>scull_kfifo<BR><SPAN 
                                style="COLOR: #ff00ff">"sh"</SPAN> did <SPAN 
                                style="COLOR: #ff0000">write</SPAN> 11 
                                bytes<BR><SPAN 
                                style="COLOR: #0000cc">[</SPAN>Tekkaman2440@SBC2440V4<SPAN 
                                style="COLOR: #0000cc">]</SPAN><SPAN 
                                style="COLOR: #0000cc">#</SPAN><SPAN 
                                style="COLOR: #0000cc">/</SPAN>tmp<SPAN 
                                style="COLOR: #0000cc">/</SPAN>scull_kfifo_test<BR>scull_kfifo<SPAN 
                                style="COLOR: #0000cc">:</SPAN> the module can 
                                <SPAN style="COLOR: #0000ff">not</SPAN> 
                                lseek!<BR>please input the command <SPAN 
                                style="COLOR: #0000cc">:</SPAN>1<BR>scull_kfifo<SPAN 
                                style="COLOR: #0000cc">:</SPAN> ioctl 
                                SCULL_KFIFO_SIZE len<SPAN 
                                style="COLOR: #0000cc">=</SPAN>11<BR>please 
                                input the command <SPAN 
                                style="COLOR: #0000cc">:</SPAN>2<BR>scull_kfifo<SPAN 
                                style="COLOR: #0000cc">:</SPAN> 
                                SCULL_KFIFO_RESET code<SPAN 
                                style="COLOR: #0000cc">=</SPAN>0<BR>please input 
                                the command <SPAN 
                                style="COLOR: #0000cc">:</SPAN>1<BR>scull_kfifo<SPAN 
                                style="COLOR: #0000cc">:</SPAN> ioctl 
                                SCULL_KFIFO_SIZE len<SPAN 
                                style="COLOR: #0000cc">=</SPAN>0<BR>please input 
                                the command <SPAN 
                                style="COLOR: #0000cc">:</SPAN>q<BR><SPAN 
                                style="COLOR: #0000cc">[</SPAN>Tekkaman2440@SBC2440V4<SPAN 
                                style="COLOR: #0000cc">]</SPAN><SPAN 
                                style="COLOR: #0000cc">#</SPAN>echo 
                                123456789012345678901234567890 <SPAN 
                                style="COLOR: #0000cc">&gt;</SPAN> <SPAN 
                                style="COLOR: #0000cc">/</SPAN>dev<SPAN 
                                style="COLOR: #0000cc">/</SPAN>scull_kfifo 
                                </FONT></SPAN></CODE></P>
                                <P 
                                style="MARGIN: 5px; LINE-HEIGHT: 150%"><CODE><SPAN 
                                style="COLOR: #000000"><FONT face=新宋体><SPAN 
                                style="COLOR: #ff00ff">"sh"</SPAN> did <SPAN 
                                style="COLOR: #ff0000">write</SPAN> 31 
                                bytes<BR><SPAN 
                                style="COLOR: #0000cc">[</SPAN>Tekkaman2440@SBC2440V4<SPAN 
                                style="COLOR: #0000cc">]</SPAN><SPAN 
                                style="COLOR: #0000cc">#</SPAN>echo 
                                123456789012345678901234567890 <SPAN 
                                style="COLOR: #0000cc">&gt;</SPAN> <SPAN 
                                style="COLOR: #0000cc">/</SPAN>dev<SPAN 
                                style="COLOR: #0000cc">/</SPAN>scull_kfifo 
                                </FONT></SPAN></CODE></P>
                                <P 
                                style="MARGIN: 5px; LINE-HEIGHT: 150%"><CODE><SPAN 
                                style="COLOR: #000000"><FONT face=新宋体><SPAN 
                                style="COLOR: #ff00ff">"sh"</SPAN> did <SPAN 
                                style="COLOR: #ff0000">write</SPAN> 31 
                                bytes<BR><SPAN 
                                style="COLOR: #0000cc">[</SPAN>Tekkaman2440@SBC2440V4<SPAN 
                                style="COLOR: #0000cc">]</SPAN><SPAN 
                                style="COLOR: #0000cc">#</SPAN>echo 1234567890 
                                <SPAN style="COLOR: #0000cc">&gt;</SPAN> <SPAN 
                                style="COLOR: #0000cc">/</SPAN>dev<SPAN 
                                style="COLOR: #0000cc">/</SPAN>scull_kfifo</FONT></SPAN></CODE></P>
                                <P 
                                style="MARGIN: 5px; LINE-HEIGHT: 150%"><CODE><SPAN 
                                style="COLOR: #000000"><FONT 
                                face=新宋体>&nbsp;<SPAN 
                                style="COLOR: #ff00ff">"sh"</SPAN> did <SPAN 
                                style="COLOR: #ff0000">write</SPAN> 2 
                                bytes<BR><SPAN 
                                style="COLOR: #ff00ff">"sh"</SPAN> did <SPAN 
                                style="COLOR: #ff0000">write</SPAN> 0 
                                bytes<BR><SPAN 
                                style="COLOR: #ff00ff">"sh"</SPAN> did <SPAN 
                                style="COLOR: #ff0000">write</SPAN> 0 
                                bytes<BR><SPAN 
                                style="COLOR: #ff00ff">"sh"</SPAN> did <SPAN 
                                style="COLOR: #ff0000">write</SPAN> 0 
                                bytes<BR><SPAN 
                                style="COLOR: #ff00ff">"sh"</SPAN> did <SPAN 
                                style="COLOR: #ff0000">write</SPAN> 0 
                                bytes<BR><SPAN 
                                style="COLOR: #ff00ff">"sh"</SPAN> did <SPAN 
                                style="COLOR: #ff0000">write</SPAN> 0 
                                bytes<BR><SPAN 
                                style="COLOR: #ff00ff">"sh"</SPAN> did <SPAN 
                                style="COLOR: #ff0000">write</SPAN> 0 
                                bytes<BR><SPAN 
                                style="COLOR: #ff00ff">"sh"</SPAN> did <SPAN 
                                style="COLOR: #ff0000">write</SPAN> 0 
                                bytes<BR><SPAN 
                                style="COLOR: #ff00ff">"sh"</SPAN> did <SPAN 
                                style="COLOR: #ff0000">write</SPAN> 0 
                                bytes<BR>printk<SPAN 
                                style="COLOR: #0000cc">:</SPAN> 204310 <SPAN 
                                style="COLOR: #ff0000">messages</SPAN> 
                                suppressed<SPAN 
                                style="COLOR: #0000cc">.</SPAN><BR><SPAN 
                                style="COLOR: #ff00ff">"sh"</SPAN> did <SPAN 
                                style="COLOR: #ff0000">write</SPAN> 0 
                                bytes<BR><BR>1234567890<BR><SPAN 
                                style="COLOR: #0000cc">[</SPAN>Tekkaman2440@SBC2440V4<SPAN 
                                style="COLOR: #0000cc">]</SPAN><SPAN 
                                style="COLOR: #0000cc">#</SPAN><SPAN 
                                style="COLOR: #0000cc">/</SPAN>tmp<SPAN 
                                style="COLOR: #0000cc">/</SPAN>scull_kfifo_test<BR>scull_kfifo<SPAN 
                                style="COLOR: #0000cc">:</SPAN> the module can 
                                <SPAN style="COLOR: #0000ff">not</SPAN> 
                                lseek!<BR>please input the command <SPAN 
                                style="COLOR: #0000cc">:</SPAN>1<BR>scull_kfifo<SPAN 
                                style="COLOR: #0000cc">:</SPAN> ioctl 
                                SCULL_KFIFO_SIZE len<SPAN 
                                style="COLOR: #0000cc">=</SPAN>64<BR>please 
                                input the command <SPAN 
                                style="COLOR: #0000cc">:</SPAN>q<BR><SPAN 
                                style="COLOR: #0000cc">[</SPAN>Tekkaman2440@SBC2440V4<SPAN 
                                style="COLOR: #0000cc">]</SPAN><SPAN 
                                style="COLOR: #0000cc">#</SPAN>cat <SPAN 
                                style="COLOR: #0000cc">/</SPAN>dev<SPAN 
                                style="COLOR: #0000cc">/</SPAN>scull_kfifo<BR>printk<SPAN 
                                style="COLOR: #0000cc">:</SPAN> 1493677 <SPAN 
                                style="COLOR: #ff0000">messages</SPAN> 
                                suppressed<SPAN 
                                style="COLOR: #0000cc">.</SPAN><BR><SPAN 
                                style="COLOR: #ff00ff">"cat"</SPAN> did <SPAN 
                                style="COLOR: #ff0000">read</SPAN> 64 
                                bytes<BR>1234<SPAN 
                                style="COLOR: #ff00ff">"cat"</SPAN> reading<SPAN 
                                style="COLOR: #0000cc">:</SPAN> going to <SPAN 
                                style="COLOR: #ff0000">sleep</SPAN><BR>56789012345678901234567890<BR>123456789012345678901234567890<BR>12<BR><SPAN 
                                style="COLOR: #0000cc">[</SPAN>Tekkaman2440@SBC2440V4<SPAN 
                                style="COLOR: #0000cc">]</SPAN><SPAN 
                                style="COLOR: #0000cc">#</SPAN><SPAN 
                                style="COLOR: #0000cc">/</SPAN>tmp<SPAN 
                                style="COLOR: #0000cc">/</SPAN>scull_kfifo_test<BR>scull_kfifo<SPAN 
                                style="COLOR: #0000cc">:</SPAN> the module can 
                                <SPAN style="COLOR: #0000ff">not</SPAN> 
                                lseek!<BR>please input the command <SPAN 
                                style="COLOR: #0000cc">:</SPAN>2<BR>scull_kfifo<SPAN 
                                style="COLOR: #0000cc">:</SPAN> 
                                SCULL_KFIFO_RESET code<SPAN 
                                style="COLOR: #0000cc">=</SPAN>0<BR>please input 
                                the command <SPAN 
                                style="COLOR: #0000cc">:</SPAN>q<BR><SPAN 
                                style="COLOR: #0000cc">[</SPAN>Tekkaman2440@SBC2440V4<SPAN 
                                style="COLOR: #0000cc">]</SPAN><SPAN 
                                style="COLOR: #0000cc">#</SPAN>rmmod 
                                scull_kfifo<BR><SPAN