Remove ancient example code from the architecture handbook.
Approved by: bcr (mentor)
This commit is contained in:
Eitan Adler
parent
1af7bc46fb
commit
ee9afa89e4
Notes:
svn2git
2020-12-08 03:00:23 +00:00
svn path=/head/; revision=40051
1 changed files with 1 additions and 165 deletions
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@ -208,171 +208,7 @@ KMOD=skeleton
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<para>This simple example pseudo-device remembers whatever values
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you write to it and can then supply them back to you when you
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read from it. Two versions are shown, one for &os; 4.X and
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one for &os; 5.X.</para>
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<example>
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<title>Example of a Sample Echo Pseudo-Device Driver for
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&os; 4.X</title>
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<programlisting>/*
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* Simple `echo' pseudo-device KLD
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*
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* Murray Stokely
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*/
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#define MIN(a,b) (((a) < (b)) ? (a) : (b))
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#include <sys/types.h>
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#include <sys/module.h>
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#include <sys/systm.h> /* uprintf */
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#include <sys/errno.h>
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#include <sys/param.h> /* defines used in kernel.h */
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#include <sys/kernel.h> /* types used in module initialization */
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#include <sys/conf.h> /* cdevsw struct */
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#include <sys/uio.h> /* uio struct */
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#include <sys/malloc.h>
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#define BUFFERSIZE 256
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/* Function prototypes */
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d_open_t echo_open;
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d_close_t echo_close;
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d_read_t echo_read;
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d_write_t echo_write;
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/* Character device entry points */
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static struct cdevsw echo_cdevsw = {
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echo_open,
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echo_close,
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echo_read,
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echo_write,
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noioctl,
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nopoll,
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nommap,
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nostrategy,
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"echo",
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33, /* reserved for lkms - /usr/src/sys/conf/majors */
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nodump,
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nopsize,
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D_TTY,
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-1
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};
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typedef struct s_echo {
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char msg[BUFFERSIZE];
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int len;
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} t_echo;
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/* vars */
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static dev_t sdev;
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static int count;
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static t_echo *echomsg;
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MALLOC_DECLARE(M_ECHOBUF);
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MALLOC_DEFINE(M_ECHOBUF, "echobuffer", "buffer for echo module");
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/*
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* This function is called by the kld[un]load(2) system calls to
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* determine what actions to take when a module is loaded or unloaded.
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*/
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static int
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echo_loader(struct module *m, int what, void *arg)
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{
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int err = 0;
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switch (what) {
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case MOD_LOAD: /* kldload */
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sdev = make_dev(<literal>&</literal>echo_cdevsw,
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0,
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UID_ROOT,
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GID_WHEEL,
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0600,
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"echo");
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/* kmalloc memory for use by this driver */
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MALLOC(echomsg, t_echo *, sizeof(t_echo), M_ECHOBUF, M_WAITOK);
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printf("Echo device loaded.\n");
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break;
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case MOD_UNLOAD:
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destroy_dev(sdev);
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FREE(echomsg,M_ECHOBUF);
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printf("Echo device unloaded.\n");
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break;
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default:
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err = EOPNOTSUPP;
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break;
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}
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return(err);
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}
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int
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echo_open(dev_t dev, int oflags, int devtype, struct proc *p)
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{
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int err = 0;
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uprintf("Opened device \"echo\" successfully.\n");
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return(err);
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}
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int
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echo_close(dev_t dev, int fflag, int devtype, struct proc *p)
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{
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uprintf("Closing device \"echo.\"\n");
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return(0);
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}
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/*
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* The read function just takes the buf that was saved via
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* echo_write() and returns it to userland for accessing.
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* uio(9)
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*/
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int
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echo_read(dev_t dev, struct uio *uio, int ioflag)
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{
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int err = 0;
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int amt;
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/*
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* How big is this read operation? Either as big as the user wants,
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* or as big as the remaining data
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*/
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amt = MIN(uio->uio_resid, (echomsg->len - uio->uio_offset > 0) ?
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echomsg->len - uio->uio_offset : 0);
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if ((err = uiomove(echomsg->msg + uio->uio_offset,amt,uio)) != 0) {
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uprintf("uiomove failed!\n");
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}
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return(err);
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}
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/*
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* echo_write takes in a character string and saves it
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* to buf for later accessing.
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*/
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int
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echo_write(dev_t dev, struct uio *uio, int ioflag)
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{
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int err = 0;
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/* Copy the string in from user memory to kernel memory */
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err = copyin(uio->uio_iov->iov_base, echomsg->msg,
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MIN(uio->uio_iov->iov_len, BUFFERSIZE - 1));
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/* Now we need to null terminate, then record the length */
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*(echomsg->msg + MIN(uio->uio_iov->iov_len, BUFFERSIZE - 1)) = 0;
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echomsg->len = MIN(uio->uio_iov->iov_len, BUFFERSIZE);
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if (err != 0) {
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uprintf("Write failed: bad address!\n");
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}
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count++;
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return(err);
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}
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DEV_MODULE(echo,echo_loader,NULL);</programlisting>
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</example>
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read from it.</para>
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<example>
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<title>Example of a Sample Echo Pseudo-Device Driver for
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