Subject: Re: should cngetc block?
To: Bill Studenmund <wrstuden@netbsd.org>
From: Kin Cho <kin@neoscale.com>
List: tech-kern
Date: 02/08/2002 11:12:40
Bill Studenmund <wrstuden@netbsd.org> writes:
> cnopen(<console dev for your port>, FREAD | FWRITE | <other opts>
> 0, curproc);
What can I use for <console dev for your port>? I tried using
cn_tab->cn_dev but that's forbidden in cnopen because cn_dev is
alrady set to our "com0" device in com_attach_subr in
com.c:
cn_tab->cn_dev = makedev(maj, sc->sc_dev.dv_unit);
> /*
> * Set up a uio to do a read, then call cnread()
> */
I have no experience with uio. Searching around, here's what I
come up with:
struct iovec aiov;
struct uio auio;
int buf[2]; // code and lsr as stored in comintr?
aiov.iov_base = buf;
aiov.iov_len = sizeof(buf);
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_offset = 0;
auio.uio_resid = 0;
auio.uio_segflg = UIO_SYSSPACE;
auio.uio_rw = UIO_READ;
auio.uio_procp = curproc;
ret = cnread(<dev>, &auio, 0);
I doubt that iov_len, uio_offset, and uio_resid are right.
Any suggestion what they should be?
-kin