From mboxrd@z Thu Jan 1 00:00:00 1970 MIME-Version: 1.0 In-Reply-To: <10bf630b13fbac21955790c6827f1ab4@quintile.net> References: <10bf630b13fbac21955790c6827f1ab4@quintile.net> Date: Fri, 1 Oct 2010 22:25:24 +0200 Message-ID: From: Francisco J Ballesteros To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net> Content-Type: text/plain; charset=UTF-8 Subject: Re: [9fans] stupid kernel question Topicbox-Message-UUID: 5c103412-ead6-11e9-9d60-3106f5b1d025 I'm kind of sleepy. But if I managed to read your mail correctly... when the kernel wants to do something that can be done with a system call (mostly read, write, open, ...), it uses the device tab directly, like in devtab[c->type].write(chan, ....), using Chan instead of fds in this case. I mean, I think that almost always you use the internal interface wrapped by the system call code. On Fri, Oct 1, 2010 at 9:17 PM, Steve Simon wrote: > how does kernel code call plan9 system calls, does it perform a > trap from kernel back into kernel space and make the request just > like a user process or is there a more direct, subtle route? > > thanks, > > -Steve > >