thanks all<br><br>
<div><span class="gmail_quote">On 10/31/07, <b class="gmail_sendername">Wang, Baojun</b> <<a href="mailto:wangbj@lzu.edu.cn">wangbj@lzu.edu.cn</a>> wrote:</span>
<blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">On Wednesday 31 October 2007 13:05:16, Bai Shuwei wrote：<br>> Hi, everyone<br>> As we know, the program on the X86 can run on the differnt ring(0, 1, 2,
<br>> 3) and the linux kernel run in the ring 0 and user program in the ring 3.<br>> And now I want to know wether there is a simple mechanism on the PowerPC<br>> architecture? thx all!<br>><br>> best regards!
<br>><br>> Buroc<br><br>powerpc has a machine state register(MSR), bit MSR_PR present the current<br>privilege level, if msr & MSR_PR, then it's from user space, otherwise(msr &<br>MSR_PR == 0) it's kernel space.
<br><br>besides, the linux implementation only use ring0 and ring3 under i386, ring0<br>is highest(kernel space), ring3 is lowest (userspace)<br><br>Wang<br>--<br>Wang, Baojun Lanzhou University<br>Distributed & Embedded System Lab
<a href="http://dslab.lzu.edu.cn">http://dslab.lzu.edu.cn</a><br>School of Information Science and Engeneering <a href="mailto:wangbj@lzu.edu.cn">wangbj@lzu.edu.cn</a><br>Tianshui South Road 222. Lanzhou 730000 .P.R.China
<br>Tel:+86-931-8912025 Fax:+86-931-8912022<br><br></blockquote></div><br><br clear="all"><br>-- <br><br>Add: Tianshui South Road 222, Lanzhou, P.R.China<br>Tel: +86-931-8912025<br>Zip Code: 730000<br>URL: <a href="http://oss.lzu.edu.cn">
oss.lzu.edu.cn</a><br>Email: <a href="mailto:baishuwei@gmail.com">baishuwei@gmail.com</a>, <a href="mailto:buroc@126.com">buroc@126.com</a>