Date: Sat, 05 Jul 2008 09:04:58 -0700 From: Marcel Moolenaar <xcllnt@mac.com> To: Takahashi Yoshihiro <nyan@jp.FreeBSD.org> Cc: ed@80386.nl, sam@freebsd.org, imp@freebsd.org, freebsd-current@freebsd.org, arch@freebsd.org Subject: Re: MPSAFE TTY schedule [uart vs sio] Message-ID: <254B5D19-E08A-43A0-AB76-43299C4AD77C@mac.com> In-Reply-To: <20080705.212422.226755141.nyan@jp.FreeBSD.org> References: <20080704.063540.1210476607.imp@bsdimp.com> <20080704.221043.226715262.nyan@jp.FreeBSD.org> <29489C48-93A2-41D9-9EF1-5395A673A9B3@mac.com> <20080705.212422.226755141.nyan@jp.FreeBSD.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Jul 5, 2008, at 5:24 AM, Takahashi Yoshihiro wrote: > In article <29489C48-93A2-41D9-9EF1-5395A673A9B3@mac.com> > Marcel Moolenaar <xcllnt@mac.com> writes: > >>> The uart probably works for some 16550 based devices but does not >>> work >>> for other one like multi-port devices. >> >> The design principle of uart(4) is that it does not know >> about multi-port hardware. It controls a single serial >> port only. For multi-port hardware you must have multiple >> nodes on a bus or use an umbrella driver, such as puc(4), >> quicc(4) or scc(4). Those drivers provide attachments for >> every port. >> >> I suspect that support for multi-port devices is not to >> hard to do on pc98... > > Many serial devices on pc98 use indirect I/O space, so resource > management is quite complex. Therefore, it may need more work you > think. I'm not sure I understand exactly what that means. Can you elaborate? > At the starting point, I have added CBus frontend and fixed console > support for pc98. Great, thanks! Could you commit sys/pc98/include/bus.h and sys/pc98/pc98/busiosubr.c at your earliest convenience. That code has to be in the kernel if I were to work on the uart module. Thanks, -- Marcel Moolenaar xcllnt@mac.com
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?254B5D19-E08A-43A0-AB76-43299C4AD77C>