Add a very simple intro-level example on how to use pud.

share/examples/pud/intro/intro.c

@@ -0,0 +1,124 @@
+/*	$NetBSD: intro.c,v 1.1 2007/11/20 18:58:17 pooka Exp $	*/
+
+/*
+ * El extra-simplo example of the userspace driver framework.
+ *
+ * Eventually there will be a library a la libpuffs (perhaps,
+ * gasp, even the same lib), but for now it's all manual until
+ * I get it figured out.
+ *
+ * So how to run this?
+ * 0) sh MAKEDEV putter (if you don't have a freshly created /dev)
+ * 1) run this program with the argument "/dev/pud"
+ * 2) mknod a char device with the major 377 (see sources below)
+ * 3) echo ascii art and jokes into device created in previous step
+ *    or read the device
+ */
+
+#include <sys/types.h>
+
+#include <dev/pud/pud_msgif.h>
+
+#include <err.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#define DEFALLOC 1024*1024
+#define ECHOSTR "Would you like some sauce diable with that?\n"
+
+#ifndef MIN
+#define MIN(a,b) ((a)<(b)?(a):(b))
+#endif
+
+int
+main(int argc, char *argv[])
+{
+	struct pud_req *pdr = malloc(DEFALLOC);
+	struct pud_conf_reg pcr;
+	int fd;
+	ssize_t n;
+	
+	if (argc != 2)
+		errx(1, "args");
+
+	/*
+	 * open pud device
+	 */
+	fd = open(argv[1], O_RDWR);
+	if (fd == -1)
+		err(1, "open");
+
+	/*
+	 * register our major number
+	 */
+	memset(&pcr, 0, sizeof(pcr));
+	pcr.pm_pdr.pdr_pth.pth_framelen = sizeof(struct pud_conf_reg);
+	pcr.pm_pdr.pdr_reqclass = PUD_REQ_CONF;
+	pcr.pm_pdr.pdr_reqtype = PUD_CONF_REG;
+
+	pcr.pm_regdev = makedev(377, 0);
+	pcr.pm_flags = 0;
+	strlcpy(pcr.pm_devname, "testdev", sizeof(pcr.pm_devname));
+
+	n = write(fd, &pcr, pcr.pm_pdr.pdr_pth.pth_framelen);
+	if (n == -1)
+		err(1, "configure write");
+
+	/*
+	 * process requests
+	 */
+	for (;;) {
+		n = read(fd, pdr, DEFALLOC);
+		printf("read %d\n", n);
+
+		if (pdr->pdr_reqclass != PUD_REQ_CDEV) {
+			printf("class %d not supported\n", pdr->pdr_reqclass);
+			abort();
+		}
+
+		switch (pdr->pdr_reqtype) {
+		case PUD_CDEV_OPEN:
+		case PUD_CDEV_CLOSE:
+			printf("got openclose %d\n", pdr->pdr_reqtype);
+			pdr->pdr_rv = 0;
+			break;
+
+		case PUD_CDEV_READ:
+		{
+			struct pud_creq_read *pc_read;
+			size_t clen;
+
+			pc_read = (void *)pdr;
+			clen = MIN(strlen(ECHOSTR), pc_read->pm_resid);
+			strncpy(pc_read->pm_data, ECHOSTR, clen);
+			pc_read->pm_resid -= clen;
+			pdr->pdr_pth.pth_framelen =
+			    sizeof(struct pud_creq_read) + clen;
+		}
+			break;
+
+		case PUD_CDEV_WRITE:
+		{
+			struct pud_creq_write *pc_write;
+
+			pc_write = (void *)pdr;
+			pc_write->pm_data[pc_write->pm_resid] = '\0';
+			printf("got via write: %s", pc_write->pm_data);
+			pdr->pdr_pth.pth_framelen =
+			    sizeof(struct pud_creq_write);
+			pc_write->pm_resid = 0;
+		}
+			break;
+
+		default:
+			abort();
+		}
+
+		n = write(fd, pdr, pdr->pdr_pth.pth_framelen);
+		printf("wrote %d %d\n", n, errno);
+	}
+}