Date: Sat, 01 Feb 1997 22:27:51 -0500 From: "Brian J. McGovern" <mcgovern@spoon.beta.com> To: hackers@freebsd.org Subject: Device Driver: Almost home(?) Message-ID: <199702020327.WAA00333@spoon.beta.com>
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Ok. I've collated a half dozen responses, and merged them in to what I hope
is less of a Frankenstein. At this point, I've modified files.i386, and moved
foo.c in to /usr/src/sys/dev/foo/foo.c. I've added a "pseudo-device foo 1"
line to the config file, and see foo.h being generated with an NFOO #define'ed
to 1. I see the make depend and the make compile the chunk, so I'm fairly sure
its making it in there. However, I don't think fooinit() is being run
properly, and I'm not sure of the call I make to register the device. As
before, if someone can sanity check me, and let me take it a step or two
further, I'd appreciate it. I think that once I can get it to where I can
tinker and debug, I should be set.
Also, I'm getting a warning about the SYSINIT macro, stating
"warning: initialization from incompatible pointer type". If someone could
give me a lead on that as well, I'd appreciate it.
Anyhow, here is the contents of foo.c:
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/reboot.h>
#include <sys/ioctl.h>
#include <sys/tty.h>
#include <sys/proc.h>
#include <sys/conf.h>
#include <sys/file.h>
#include <sys/uio.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/syslog.h>
#ifdef DEVFS
#include <sys/devfsext.h>
#endif
#include <machine/clock.h>
#include <i386/isa/isa.h>
#include <i386/isa/isa_device.h>
static char message[] = "The quick brown fox jumps over a lazy dog\n";
#define CDEV_MAJOR 20
static d_read_t fooread;
static struct cdevsw foo_cdevsw =
{
nxopen, nxclose, fooread, nxwrite,
nxioctl, nxstop, nxreset, nxdevtotty,
nxselect, nxmmap, NULL, "foo", NULL, -1
};
static void fooinit(void)
{
dev_t dev;
printf("Test character driver\n");
cdevsw_add(&dev,&foo_cdevsw,NULL);
}
static int fooread(dev,myuio, flag)
dev_t dev;
struct uio *myuio;
int flag;
{
unsigned char *buffer_pointer;
int toread;
if ((myuio->uio_iovcnt != 1) || (minor(dev) != 0))
return ENODEV;
while(myuio->uio_resid)
{
buffer_pointer = (message + (myuio->uio_offset % sizeof(message)));
toread = ((long unsigned int)(message + sizeof(message)) - (long unsigned int)buffer_pointer);
uiomove(buffer_pointer, toread, myuio);
myuio->uio_offset + toread;
myuio->uio_resid = myuio->uio_resid - toread;
}
return 0;
}
SYSINIT(foodev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE+CDEV_MAJOR, fooinit, NULL);
As always, thanks in advance.
-Brian
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