From mboxrd@z Thu Jan 1 00:00:00 1970 To: zjzhou@newrocktech.com Cc: "'Mailing List: linuxppc-dev'" Subject: Re: A question on kernel clock: From: Wolfgang Denk Mime-version: 1.0 Content-type: text/plain; charset=ISO-8859-1 In-reply-to: Your message of "Tue, 30 Dec 2003 18:45:42 +0800." <000501c3cec2$130dbab0$b702a8c0@newrock2> Date: Tue, 30 Dec 2003 19:49:46 +0100 Message-Id: <20031230184951.94F07C12DD@atlas.denx.de> Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: Dear John, in message <000501c3cec2$130dbab0$b702a8c0@newrock2> you wrote: > > The processor I mentioned is MPC82xx. Now, I have kernel from kernel.org [I guessed that from the ...BRG8 part.] > run on the board. But, my "nsleep()" is not exactly. So, I want to > realize the timer mechanism of Linux used. > (1) which timer is used for nsleep? I have not the slightest idea. I don't know of any standard funtion with that name - neither in user space nor in kernel code. > (2) can udelay() be changed to be preempted by other process? That makes little sense. If you allow to run other prcesses inbetween you will have looong delays - udelay() was not made for such purposes, but for very short delays (as the name suggests: in the range of a few microseconds). > (3) which is good choice for Kernel timeslice? What's wrong with the standard 10 ms ? > Additional, could we develop a bootloader like vxworks' bootloader? ( > vxworks bootloader is a little vxworks, I think.) Of course you can. But what for? If you like the VxWorks boot loader, then use it. If you like something more powerful, use U-Boot. Best regards, Wolfgang Denk -- Software Engineering: Embedded and Realtime Systems, Embedded Linux Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd@denx.de This all sounds complicated, but it mostly does excatly what you ex- pect. It's just difficult for us to explain what you expect... - L. Wall & R. L. Schwartz, _Programming Perl_ ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/