>Number: 55693 >Category: docs >Synopsis: Howto make a kernel module for a pseudo-device under 5.X >Confidential: no >Severity: serious >Priority: low >Responsible: kensmith >State: closed >Quarter: >Keywords: >Date-Required: >Class: update >Submitter-Id: current-users >Arrival-Date: Mon Aug 18 05:40:15 PDT 2003 >Closed-Date: Thu Sep 25 06:03:14 PDT 2003 >Last-Modified: Thu Sep 25 06:03:14 PDT 2003 >Originator: Xride >Release: FreeBSD 5.1-CURRENT i386 >Organization: >Environment: Changed the pseudo-device kernel module code, from the arch-handbook, so it will work under 5.X. --- chapter.diff begins here --- --- /usr/doc/en_US.ISO8859-1/books/arch-handbook/driverbasics/chapter.sgml Thu Aug 7 01:48:02 2003 +++ chapter.sgml Mon Aug 18 13:42:46 2003 @@ -335,6 +335,168 @@ DEV_MODULE(echo,echo_loader,NULL); + For the 5.X serie this is how the code for the pseudo-device + should look: + +/* + * Simple `echo' pseudo-device KLD + * + * Murray Stokely + */ + +/* + * Conveted to 5.X by S&oring;ren (Xride) Straarup + */ + + +#include <sys/types.h> +#include <sys/module.h> +#include <sys/systm.h> /* uprintf */ +#include <sys/errno.h> +#include <sys/param.h> /* defines used in kernel.h */ +#include <sys/kernel.h> /* types used in module initialization */ +#include <sys/conf.h> /* cdevsw struct */ +#include <sys/uio.h> /* uio struct */ +#include <sys/malloc.h> + +#define BUFFERSIZE 256 +#define CDEV_MAJOR 33 + +/* Function prototypes */ +static d_open_t echo_open; +static d_close_t echo_close; +static d_read_t echo_read; +static d_write_t echo_write; + +/* Character device entry points */ +static struct cdevsw echo_cdevsw = { + .d_open = echo_open, + .d_close = echo_close, + .d_maj = CDEV_MAJOR, + .d_name = "echo", + .d_read = echo_read, + .d_write = echo_write +}; + +typedef struct s_echo { + char msg[BUFFERSIZE]; + int len; +} t_echo; + +/* vars */ +static dev_t echo_dev; +static int count; +static t_echo *echomsg; +static int len; + + +MALLOC_DECLARE(M_ECHOBUF); +MALLOC_DEFINE(M_ECHOBUF, "echobuffer", "buffer for echo module"); + +/* + * This function acts is called by the kld[un]load(2) system calls to + * determine what actions to take when a module is loaded or unloaded. + */ + +static int +echo_loader(struct module *m, int what, void *arg) +{ + int err = 0; + + switch (what) { + case MOD_LOAD: /* kldload */ + echo_dev = make_dev(&echo_cdevsw, + 0, + UID_ROOT, + GID_WHEEL, + 0600, + "echo"); + /* kmalloc memory for use by this driver */ + /* malloc(256,M_ECHOBUF,M_WAITOK); */ + MALLOC(echomsg, t_echo *, sizeof(t_echo), M_ECHOBUF, M_WAITOK); + printf("Echo device loaded.\n"); + break; + case MOD_UNLOAD: + destroy_dev(echo_dev); + FREE(echomsg,M_ECHOBUF); + printf("Echo device unloaded.\n"); + break; + default: + err = EINVAL; + break; + } + return(err); +} + +static int +echo_open(dev_t dev, int oflags, int devtype, struct thread *p) +{ + int err = 0; + + uprintf("Opened device \"echo\" successfully.\n"); + return(err); +} + +static int +echo_close(dev_t dev, int fflag, int devtype, struct thread *p) +{ + uprintf("Closing device \"echo.\"\n"); + return(0); +} + +/* + * The read function just takes the buf that was saved via + * echo_write() and returns it to userland for accessing. + * uio(9) + */ + +static int +echo_read(dev_t dev, struct uio *uio, int ioflag) +{ + int err = 0; + int amt; + + /* How big is this read operation? Either as big as the user wants, + or as big as the remaining data */ + amt = MIN(uio->uio_resid, (echomsg->len - uio->uio_offset > 0) ? echomsg->l +en - uio->uio_offset : 0); + if ((err = uiomove(echomsg->msg + uio->uio_offset,amt,uio)) != 0) { + uprintf("uiomove failed!\n"); + } + + return err; +} + +/* + * echo_write takes in a character string and saves it + * to buf for later accessing. + */ + +static int +echo_write(dev_t dev, struct uio *uio, int ioflag) +{ + int err = 0; + + /* Copy the string in from user memory to kernel memory */ + err = copyin(uio->uio_iov->iov_base, echomsg->msg, MIN(uio->uio_iov->iov_le +n,BUFFERSIZE)); + + /* Now we need to null terminate */ + *(echomsg->msg + MIN(uio->uio_iov->iov_len,BUFFERSIZE)) = 0; + /* Record the length */ + echomsg->len = MIN(uio->uio_iov->iov_len,BUFFERSIZE); + + if (err != 0) { + uprintf("Write failed: bad address!\n"); + } + + count++; + return(err); +} + +DEV_MODULE(echo,echo_loader,NULL); + + To install this driver you will first need to make a node on your filesystem with a command such as: --- chapter.diff ends here --- >Description: >How-To-Repeat: >Fix: >Release-Note: >Audit-Trail: State-Changed-From-To: open->closed State-Changed-By: kensmith State-Changed-When: Thu Sep 25 06:00:11 PDT 2003 State-Changed-Why: Patch committed with minor changes: - formatted code to be style(9) compliant - minor spelling/grammar changes - minor fix of markup tags () Thanks! http://www.freebsd.org/cgi/query-pr.cgi?pr=55693 >Unformatted: