Linux Device Drivers 3 examples

15 files changed, 907 insertions, 0 deletions

diff --git a/misc-progs/Makefile b/misc-progs/Makefile
new file mode 100644
index 0000000..759ddec
--- /dev/null
+++ b/misc-progs/Makefile
@@ -0,0 +1,13 @@
+
+FILES = nbtest load50 mapcmp polltest mapper setlevel setconsole inp outp \
+	datasize dataalign netifdebug
+
+KERNELDIR ?= /lib/modules/$(shell uname -r)/build
+INCLUDEDIR = $(KERNELDIR)/include
+CFLAGS = -O2 -fomit-frame-pointer -Wall -I$(INCLUDEDIR)
+
+all: $(FILES)
+
+clean:
+	rm -f $(FILES) *~ core
+
diff --git a/misc-progs/asynctest.c b/misc-progs/asynctest.c
new file mode 100644
index 0000000..8dcb458
--- /dev/null
+++ b/misc-progs/asynctest.c
@@ -0,0 +1,57 @@
+/*
+ * asynctest.c: use async notification to read stdin
+ *
+ * Copyright (C) 2001 Alessandro Rubini and Jonathan Corbet
+ * Copyright (C) 2001 O'Reilly & Associates
+ *
+ * The source code in this file can be freely used, adapted,
+ * and redistributed in source or binary form, so long as an
+ * acknowledgment appears in derived source files.  The citation
+ * should list that the code comes from the book "Linux Device
+ * Drivers" by Alessandro Rubini and Jonathan Corbet, published
+ * by O'Reilly & Associates.   No warranty is attached;
+ * we cannot take responsibility for errors or fitness for use.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <signal.h>
+#include <fcntl.h>
+
+int gotdata=0;
+void sighandler(int signo)
+{
+    if (signo==SIGIO)
+        gotdata++;
+    return;
+}
+
+char buffer[4096];
+
+int main(int argc, char **argv)
+{
+    int count;
+    struct sigaction action;
+
+    memset(&action, 0, sizeof(action));
+    action.sa_handler = sighandler;
+    action.sa_flags = 0;
+
+    sigaction(SIGIO, &action, NULL);
+
+    fcntl(STDIN_FILENO, F_SETOWN, getpid());
+    fcntl(STDIN_FILENO, F_SETFL, fcntl(STDIN_FILENO, F_GETFL) | FASYNC);
+
+    while(1) {
+        /* this only returns if a signal arrives */
+        sleep(86400); /* one day */
+        if (!gotdata)
+            continue;
+        count=read(0, buffer, 4096);
+        /* buggy: if avail data is more than 4kbytes... */
+        write(1,buffer,count);
+        gotdata=0;
+    }
+}
diff --git a/misc-progs/dataalign.c b/misc-progs/dataalign.c
new file mode 100644
index 0000000..1042ab7
--- /dev/null
+++ b/misc-progs/dataalign.c
@@ -0,0 +1,58 @@
+/*
+ * dataalign.c -- show alignment needs
+ *
+ * Copyright (C) 2001 Alessandro Rubini and Jonathan Corbet
+ * Copyright (C) 2001 O'Reilly & Associates
+ *
+ * The source code in this file can be freely used, adapted,
+ * and redistributed in source or binary form, so long as an
+ * acknowledgment appears in derived source files.  The citation
+ * should list that the code comes from the book "Linux Device
+ * Drivers" by Alessandro Rubini and Jonathan Corbet, published
+ * by O'Reilly & Associates.   No warranty is attached;
+ * we cannot take responsibility for errors or fitness for use.
+ *
+ * This runs with any Linux kernel (not any Unix, because of <linux/types.h>)
+ */
+#include <stdio.h>
+#include <sys/utsname.h>
+#include <linux/types.h>
+
+/*
+ * Define several data structures, all of them start with a lone char
+ * in order to present an unaligned offset for the next field
+ */
+struct c   {char c;  char      t;} c;
+struct s   {char c;  short     t;} s;
+struct i   {char c;  int       t;} i;
+struct l   {char c;  long      t;} l;
+struct ll  {char c;  long long t;} ll;
+struct p   {char c;  void *    t;} p;
+struct u1b {char c;  __u8      t;} u1b;
+struct u2b {char c;  __u16     t;} u2b;
+struct u4b {char c;  __u32     t;} u4b;
+struct u8b {char c;  __u64     t;} u8b;
+
+int main(int argc, char **argv)
+{
+    struct utsname name;
+
+    uname(&name); /* never fails :) */
+    printf("arch  Align:  char  short  int  long   ptr long-long "
+	   " u8 u16 u32 u64\n");
+    printf(       "%-12s  %3i   %3i   %3i   %3i   %3i   %3i      "
+	   "%3i %3i %3i %3i\n",
+	   name.machine,
+	   /* note that gcc can subtract void * values, but it's not ansi */
+	   (int)((void *)(&c.t)   - (void *)&c),
+	   (int)((void *)(&s.t)   - (void *)&s),
+	   (int)((void *)(&i.t)   - (void *)&i),
+	   (int)((void *)(&l.t)   - (void *)&l),
+	   (int)((void *)(&p.t)   - (void *)&p),
+	   (int)((void *)(&ll.t)  - (void *)&ll),
+	   (int)((void *)(&u1b.t) - (void *)&u1b),
+	   (int)((void *)(&u2b.t) - (void *)&u2b),
+	   (int)((void *)(&u4b.t) - (void *)&u4b),
+	   (int)((void *)(&u8b.t) - (void *)&u8b));
+    return 0;
+}
diff --git a/misc-progs/datasize.c b/misc-progs/datasize.c
new file mode 100644
index 0000000..bf63423
--- /dev/null
+++ b/misc-progs/datasize.c
@@ -0,0 +1,35 @@
+/*
+ * datasize.c -- print the size of common data items
+ * This runs with any Linux kernel (not any Unix, because of <linux/types.h>)
+ *
+ * Copyright (C) 2001 Alessandro Rubini and Jonathan Corbet
+ * Copyright (C) 2001 O'Reilly & Associates
+ *
+ * The source code in this file can be freely used, adapted,
+ * and redistributed in source or binary form, so long as an
+ * acknowledgment appears in derived source files.  The citation
+ * should list that the code comes from the book "Linux Device
+ * Drivers" by Alessandro Rubini and Jonathan Corbet, published
+ * by O'Reilly & Associates.   No warranty is attached;
+ * we cannot take responsibility for errors or fitness for use.
+ */
+#include <stdio.h>
+#include <sys/utsname.h>
+#include <linux/types.h>
+
+int main(int argc, char **argv)
+{
+    struct utsname name;
+
+    uname(&name); /* never fails :) */
+    printf("arch   Size:  char  short  int  long   ptr long-long "
+	   " u8 u16 u32 u64\n");
+    printf(       "%-12s  %3i   %3i   %3i   %3i   %3i   %3i      "
+	   "%3i %3i %3i %3i\n",
+	   name.machine,
+	   (int)sizeof(char), (int)sizeof(short), (int)sizeof(int),
+	   (int)sizeof(long),
+	   (int)sizeof(void *), (int)sizeof(long long), (int)sizeof(__u8),
+	   (int)sizeof(__u16), (int)sizeof(__u32), (int)sizeof(__u64));
+    return 0;
+}
diff --git a/misc-progs/gdbline b/misc-progs/gdbline
new file mode 100644
index 0000000..d66572e
--- /dev/null
+++ b/misc-progs/gdbline
@@ -0,0 +1,19 @@
+#!/bin/bash
+#
+# $Id: gdbline,v 1.1 2004/08/02 16:27:55 corbet Exp $
+#
+# gdbline module image
+#
+# Outputs an add-symbol-file line suitable for pasting into gdb to examine
+# a loaded module.
+#
+cd /sys/module/$1/sections
+echo -n add-symbol-file $2 `/bin/cat .text`
+
+for section in .[a-z]* *; do
+    if [ $section != ".text" ]; then
+	    echo  " \\"
+	    echo -n "       -s" $section `/bin/cat $section`
+    fi
+done
+echo
diff --git a/misc-progs/inp.c b/misc-progs/inp.c
new file mode 100644
index 0000000..282d570
--- /dev/null
+++ b/misc-progs/inp.c
@@ -0,0 +1,129 @@
+/* 
+ * inp.c -- read all the ports specified in hex on the command line.
+ *     The program uses the faster ioperm/iopl calls on x86, /dev/port
+ *     on other platforms. The program acts as inb/inw/inl according
+ *     to its own name
+ *
+ * Copyright (C) 1998,2000,2001 Alessandro Rubini
+ * 
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <asm/io.h> /* linux-specific */
+
+#ifdef __GLIBC__
+#  include <sys/perm.h>
+#endif
+
+#define PORT_FILE "/dev/port"
+
+char *prgname;
+
+#ifdef __i386__
+static int read_and_print_one(unsigned int port,int size)
+{
+    static int iopldone = 0;
+
+    if (port > 1024) {
+	if (!iopldone && iopl(3)) {
+	    fprintf(stderr, "%s: iopl(): %s\n", prgname, strerror(errno));
+	    return 1;
+	}
+	iopldone++;
+    } else if (ioperm(port,size,1)) {
+	fprintf(stderr, "%s: ioperm(%x): %s\n", prgname,
+		port, strerror(errno));
+	return 1;
+    }
+
+    if (size == 4)
+	printf("%04x: %08x\n", port, inl(port));
+    else if (size == 2)
+	printf("%04x: %04x\n", port, inw(port));
+    else
+	printf("%04x: %02x\n", port, inb(port));
+    return 0;
+}
+#else /* not i386 */
+
+static int read_and_print_one(unsigned int port,int size)
+{
+    static int fd = -1;
+    unsigned char b; unsigned short w; unsigned int l;
+
+    if (fd < 0)
+	fd = open(PORT_FILE, O_RDONLY);
+    if (fd < 0) {
+	fprintf(stderr, "%s: %s: %s\n", prgname, PORT_FILE, strerror(errno));
+	return 1;
+    }
+    lseek(fd, port, SEEK_SET);
+    
+    if (size == 4) {
+	read(fd, &l, 4);
+	printf("%04x: 0x%08x\n", port, l);
+    } else if (size == 2) {
+	read(fd, &w, 2);
+	printf("%04x: 0x%04x\n", port, w & 0xffff);
+    } else {
+	read(fd, &b, 1);
+	printf("%04x: 0x%02x\n", port, b & 0xff);
+    }
+    return 0;
+}
+
+#endif /* i386 */
+
+
+int main(int argc, char **argv)
+{
+    unsigned int i, n, port, size, error = 0;
+    
+    prgname = argv[0];
+    /* find the data size */
+    switch (prgname[strlen(prgname)-1]) {
+        case 'w': size = 2; break;
+        case 'l': size = 4; break;
+        case 'b': case 'p': default:
+	    size = 1;
+    }
+
+    setuid(0); /* if we're setuid, force it on */
+    for (i = 1; i < argc; i++) {
+        if ( sscanf(argv[i], "%x%n", &port, &n) < 1
+	      || n != strlen(argv[i]) ) {
+	    fprintf(stderr, "%s: argument \"%s\" is not a hex number\n",
+		    argv[0], argv[i]);
+	    error++; continue;
+	}
+	if (port & (size-1)) {
+	    fprintf(stderr, "%s: argument \"%s\" is not properly aligned\n",
+		    argv[0], argv[i]);
+	    error++; continue;
+	}
+	error += read_and_print_one(port, size);
+    }
+    exit (error ? 1 : 0);
+}
+
diff --git a/misc-progs/load50.c b/misc-progs/load50.c
new file mode 100644
index 0000000..f9d93a0
--- /dev/null
+++ b/misc-progs/load50.c
@@ -0,0 +1,38 @@
+/*
+ * load50.c -- a simple busy-looping tool. 
+ * Obviously, this runs with any kernel and any Unix
+ *
+ * Copyright (C) 2001 Alessandro Rubini and Jonathan Corbet
+ * Copyright (C) 2001 O'Reilly & Associates
+ *
+ * The source code in this file can be freely used, adapted,
+ * and redistributed in source or binary form, so long as an
+ * acknowledgment appears in derived source files.  The citation
+ * should list that the code comes from the book "Linux Device
+ * Drivers" by Alessandro Rubini and Jonathan Corbet, published
+ * by O'Reilly & Associates.   No warranty is attached;
+ * we cannot take responsibility for errors or fitness for use.
+ */ 
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+int main(int argc, char **argv)
+{
+	int i, load=50;
+
+	if (argc==2) {
+		load=atoi(argv[1]);
+	}
+	printf("Bringing load to %i\n",load);
+  
+	for (i=0; i<load; i++)
+		if (fork()==0)
+			break;
+
+	while(1)
+		;
+	return 0;
+}
+
diff --git a/misc-progs/mapcmp.c b/misc-progs/mapcmp.c
new file mode 100644
index 0000000..8ef8831
--- /dev/null
+++ b/misc-progs/mapcmp.c
@@ -0,0 +1,87 @@
+/*
+ * Simple program to compare two mmap'd areas.
+ *
+ * Copyright (C) 2001 Alessandro Rubini and Jonathan Corbet
+ * Copyright (C) 2001 O'Reilly & Associates
+ *
+ * The source code in this file can be freely used, adapted,
+ * and redistributed in source or binary form, so long as an
+ * acknowledgment appears in derived source files.  The citation
+ * should list that the code comes from the book "Linux Device
+ * Drivers" by Alessandro Rubini and Jonathan Corbet, published
+ * by O'Reilly & Associates.   No warranty is attached;
+ * we cannot take responsibility for errors or fitness for use.
+ *
+ * $Id: mapcmp.c,v 1.2 2004/03/05 17:35:41 corbet Exp $
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/errno.h>
+#include <fcntl.h>
+
+static char *mapdev (const char *, unsigned long, unsigned long);
+#define PAGE_SIZE 4096
+
+/*
+ * memcmp dev1 dev2 offset pages
+ */
+int main (int argc, char **argv)
+{
+	unsigned long offset, size, i;
+	char *addr1, *addr2;
+/*
+ * Sanity check.
+ */
+	if (argc != 5)
+	{
+		fprintf (stderr, "Usage: mapcmp dev1 dev2 offset pages\n");
+		exit (1);
+	}
+/*
+ * Map the two devices.
+ */
+	offset = strtoul (argv[3], NULL, 16);
+	size = atoi (argv[4])*PAGE_SIZE;
+	printf ("Offset is 0x%lx\n", offset);
+	addr1 = mapdev (argv[1], offset, size);
+	addr2 = mapdev (argv[2], offset, size);
+/*
+ * Do the comparison.
+ */
+	printf ("Comparing...");
+	fflush (stdout);
+	for (i = 0; i < size; i++)
+		if (*addr1++ != *addr2++)
+		{
+			printf ("areas differ at byte %ld\n", i);
+			exit (0);
+		}
+	printf ("areas are identical.\n");
+	exit (0);
+}
+
+
+
+static char *mapdev (const char *dev, unsigned long offset,
+		unsigned long size)
+{
+	char *addr;
+	int fd = open (dev, O_RDONLY);
+
+	if (fd < 0)
+	{
+		perror (dev);
+		exit (1);
+	}
+	addr = mmap (0, size, PROT_READ, MAP_PRIVATE, fd, offset);
+	if (addr == MAP_FAILED)
+	{
+		perror (dev);
+		exit (1);
+	}
+	printf ("Mapped %s (%lu @ %lx) at %p\n", dev, size, offset, addr);
+	return (addr);
+}
diff --git a/misc-progs/mapper.c b/misc-progs/mapper.c
new file mode 100644
index 0000000..ae8db09
--- /dev/null
+++ b/misc-progs/mapper.c
@@ -0,0 +1,71 @@
+/*
+ * mapper.c -- simple file that mmap()s a file region and prints it
+ *
+ * Copyright (C) 1998,2000,2001 Alessandro Rubini
+ * 
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <errno.h>
+#include <limits.h>
+
+int main(int argc, char **argv)
+{
+    char *fname;
+    FILE *f;
+    unsigned long offset, len;
+    void *address;
+
+    if (argc !=4
+       || sscanf(argv[2],"%li", &offset) != 1
+       || sscanf(argv[3],"%li", &len) != 1) {
+        fprintf(stderr, "%s: Usage \"%s <file> <offset> <len>\"\n", argv[0],
+                argv[0]);
+        exit(1);
+    }
+    /* the offset might be big (e.g., PCI devices), but conversion trims it */
+    if (offset == INT_MAX) {
+	if (argv[2][1]=='x')
+            sscanf(argv[2]+2, "%lx", &offset);
+        else
+            sscanf(argv[2], "%lu", &offset);
+    }
+
+    fname=argv[1];
+
+    if (!(f=fopen(fname,"r"))) {
+        fprintf(stderr, "%s: %s: %s\n", argv[0], fname, strerror(errno));
+        exit(1);
+    }
+
+    address=mmap(0, len, PROT_READ, MAP_FILE | MAP_PRIVATE, fileno(f), offset);
+
+    if (address == (void *)-1) {
+        fprintf(stderr,"%s: mmap(): %s\n",argv[0],strerror(errno));
+        exit(1);
+    }
+    fclose(f);
+    fprintf(stderr, "mapped \"%s\" from %lu (0x%08lx) to %lu (0x%08lx)\n",
+            fname, offset, offset, offset+len, offset+len);
+
+    fwrite(address, 1, len, stdout);
+    return 0;
+}
+        
diff --git a/misc-progs/nbtest.c b/misc-progs/nbtest.c
new file mode 100644
index 0000000..6a0bd54
--- /dev/null
+++ b/misc-progs/nbtest.c
@@ -0,0 +1,44 @@
+/*
+ * nbtest.c: read and write in non-blocking mode
+ * This should run with any Unix
+ *
+ * Copyright (C) 2001 Alessandro Rubini and Jonathan Corbet
+ * Copyright (C) 2001 O'Reilly & Associates
+ *
+ * The source code in this file can be freely used, adapted,
+ * and redistributed in source or binary form, so long as an
+ * acknowledgment appears in derived source files.  The citation
+ * should list that the code comes from the book "Linux Device
+ * Drivers" by Alessandro Rubini and Jonathan Corbet, published
+ * by O'Reilly & Associates.   No warranty is attached;
+ * we cannot take responsibility for errors or fitness for use.
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <errno.h>
+
+char buffer[4096];
+
+int main(int argc, char **argv)
+{
+	int delay = 1, n, m = 0;
+
+	if (argc > 1)
+		delay=atoi(argv[1]);
+	fcntl(0, F_SETFL, fcntl(0,F_GETFL) | O_NONBLOCK); /* stdin */
+	fcntl(1, F_SETFL, fcntl(1,F_GETFL) | O_NONBLOCK); /* stdout */
+
+	while (1) {
+		n = read(0, buffer, 4096);
+		if (n >= 0)
+			m = write(1, buffer, n);
+		if ((n < 0 || m < 0) && (errno != EAGAIN))
+			break;
+		sleep(delay);
+	}
+	perror(n < 0 ? "stdin" : "stdout");
+	exit(1);
+}
diff --git a/misc-progs/netifdebug.c b/misc-progs/netifdebug.c
new file mode 100644
index 0000000..6f0ce75
--- /dev/null
+++ b/misc-progs/netifdebug.c
@@ -0,0 +1,84 @@
+/*
+ * netifdebug.c -- change the IFF_DEBUG flag of an interface
+ *
+ * Copyright (C) 2001 Alessandro Rubini and Jonathan Corbet
+ * Copyright (C) 2001 O'Reilly & Associates
+ *
+ * The source code in this file can be freely used, adapted,
+ * and redistributed in source or binary form, so long as an
+ * acknowledgment appears in derived source files.  The citation
+ * should list that the code comes from the book "Linux Device
+ * Drivers" by Alessandro Rubini and Jonathan Corbet, published
+ * by O'Reilly & Associates.   No warranty is attached;
+ * we cannot take responsibility for errors or fitness for use.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+#include <net/if.h>
+#include <netinet/in.h>
+
+int main(int argc, char **argv)
+{
+    int action = -1, sock;
+    struct ifreq req;
+    char *actname;
+
+    if (argc < 2) {
+        fprintf(stderr,"%s: usage is \"%s <ifname> [<on|off|tell>]\"\n",
+                argv[0],argv[0]);
+        exit(1);
+    }
+    if (argc==2)
+        actname="tell";
+    else
+        actname=argv[2];
+
+    /* a silly raw socket just for ioctl()ling it */
+    sock = socket(AF_INET, SOCK_RAW, IPPROTO_RAW);
+    if (sock < 0) {
+        fprintf(stderr, "%s: socket(): %s\n", argv[0],strerror(errno));
+        exit(1);
+    }
+
+    /* retrieve flags */
+    strcpy(req.ifr_name, argv[1]);
+    if ( ioctl(sock, SIOCGIFFLAGS, &req) < 0) {
+        fprintf(stderr, " %s: ioctl(SIOCGIFFLAGS): %s\n",
+                argv[0],strerror(errno));
+        exit(1);
+    }
+
+    if (!strcmp(actname,"on")
+        || !strcmp(actname,"+")
+        || !strcmp(actname,"1"))
+        action = IFF_DEBUG;
+
+    if (!strcmp(actname,"off")
+        || !strcmp(actname,"-")
+        || !strcmp(actname,"0"))
+        action = 0;
+
+    if (!strcmp(actname,"tell")
+        || actname[0]=='t') {
+        printf("%s: debug is %s\n", argv[1],
+               req.ifr_flags & IFF_DEBUG ? "on" : "off");
+        exit(0);
+    }
+
+    req.ifr_flags &= ~IFF_DEBUG;
+    req.ifr_flags |= action;
+
+    if ( ioctl(sock, SIOCSIFFLAGS, &req) < 0) {
+        fprintf(stderr, " %s: ioctl(SIOCSIFFLAGS): %s\n",
+                argv[0],strerror(errno));
+        exit(1);
+    }
+    exit(0);
+}
diff --git a/misc-progs/outp.c b/misc-progs/outp.c
new file mode 100644
index 0000000..219d613
--- /dev/null
+++ b/misc-progs/outp.c
@@ -0,0 +1,136 @@
+/* 
+ * outp.c -- write all the ports specified in hex on the command line.
+ *     The program uses the faster ioperm/iopl calls on x86, /dev/port
+ *     on other platforms. The program acts as outb/outw/outl according
+ *     to its own name
+ *
+ * Copyright (C) 1998,2000,2001 Alessandro Rubini
+ * 
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <asm/io.h> /* linux-specific */
+
+#ifdef __GLIBC__
+#  include <sys/perm.h>
+#endif
+
+#define PORT_FILE "/dev/port"
+
+char *prgname;
+
+#ifdef __i386__
+static int write_one(unsigned int port, unsigned int val, int size)
+{
+    static int iopldone = 0;
+
+    if (port > 1024) {
+	if (!iopldone && iopl(3)) {
+	    fprintf(stderr, "%s: iopl(): %s\n", prgname, strerror(errno));
+	    return 1;
+	}
+	iopldone++;
+    } else if (ioperm(port,size,1)) {
+	fprintf(stderr, "%s: ioperm(%x): %s\n", prgname,
+		port, strerror(errno));
+	return 1;
+    }
+
+    if (size == 4)
+	outl(val, port);
+    else if (size == 2)
+	outw(val&0xffff, port);
+    else
+	outb(val&0xff, port);
+    return 0;
+}
+#else /* not i386 */
+
+static int write_one(unsigned int port, unsigned int val, int size)
+{
+    static int fd = -1;
+    unsigned char b; unsigned short w;
+
+    if (fd < 0)
+	fd = open(PORT_FILE, O_WRONLY);
+    if (fd < 0) {
+	fprintf(stderr, "%s: %s: %s\n", prgname, PORT_FILE, strerror(errno));
+	return 1;
+    }
+    lseek(fd, port, SEEK_SET);
+    
+    if (size == 4) {
+	write(fd, &val, 4);
+    } else if (size == 2) {
+	w = val;
+	write(fd, &w, 2);
+    } else {
+	b = val;
+	write(fd, &b, 1);
+    }
+    return 0;
+}
+
+#endif /* i386 */
+
+int main(int argc, char **argv)
+{
+    unsigned int i, n, port, val, size, error = 0;
+    
+    prgname = argv[0];
+    /* find the data size */
+    switch (prgname[strlen(prgname)-1]) {
+        case 'w': size = 2; break;
+        case 'l': size = 4; break;
+        case 'b': case 'p': default:
+	    size = 1;
+    }
+    setuid(0); /* if we're setuid, force it on */
+    for (i=1;i<argc-1;i++) {
+        if ( sscanf(argv[i], "%x%n", &port, &n) < 1
+	      || n != strlen(argv[i]) ) {
+	    fprintf(stderr, "%s: argument \"%s\" is not a hex number\n",
+		    argv[0], argv[i]);
+	    error++; continue;
+	}
+	if (port & (size-1)) {
+	    fprintf(stderr, "%s: argument \"%s\" is not properly aligned\n",
+		    argv[0], argv[i]);
+	    error++; continue;
+	}
+        if ( sscanf(argv[i+1], "%x%n", &val, &n) < 1
+	      || n != strlen(argv[i+1]) ) {
+	    fprintf(stderr, "%s: argument \"%s\" is not a hex number\n",
+		    argv[0], argv[i+1]);
+	    error++; continue;
+	}
+	if (size < 4 && val > (size == 1 ? 0xff : 0xffff)) {
+	    fprintf(stderr, "%s: argument \"%s\" out of range\n",
+		    argv[0], argv[i+1]);
+	    error++; continue;
+	}
+	error += write_one(port, val, size);
+    }
+    exit (error ? 1 : 0);
+}
diff --git a/misc-progs/polltest.c b/misc-progs/polltest.c
new file mode 100644
index 0000000..fdc461d
--- /dev/null
+++ b/misc-progs/polltest.c
@@ -0,0 +1,47 @@
+/*
+ * Test out reading with poll()
+ * This should run with any Unix
+ *
+ * Copyright (C) 2003 Alessandro Rubini and Jonathan Corbet
+ * Copyright (C) 2003 O'Reilly & Associates
+ *
+ * The source code in this file can be freely used, adapted,
+ * and redistributed in source or binary form, so long as an
+ * acknowledgment appears in derived source files.  The citation
+ * should list that the code comes from the book "Linux Device
+ * Drivers" by Alessandro Rubini and Jonathan Corbet, published
+ * by O'Reilly & Associates.   No warranty is attached;
+ * we cannot take responsibility for errors or fitness for use.
+ *
+ * $Id: polltest.c,v 1.1 2003/02/07 18:01:38 corbet Exp $
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <sys/poll.h>
+#include <fcntl.h>
+
+char buffer[4096];
+
+int main(int argc, char **argv)
+{
+    struct pollfd pfd;
+    int n;
+
+    fcntl(0, F_SETFL, fcntl(0,F_GETFL) | O_NONBLOCK); /* stdin */
+    pfd.fd = 0;  /* stdin */
+    pfd.events = POLLIN;
+
+    while (1) {
+        n=read(0, buffer, 4096);
+        if (n >= 0)
+            write(1, buffer, n);
+	n = poll(&pfd, 1, -1);
+	if (n < 0)
+	    break;
+    }
+    perror( n<0 ? "stdin" : "stdout");
+    exit(1);
+}
diff --git a/misc-progs/setconsole.c b/misc-progs/setconsole.c
new file mode 100644
index 0000000..04bc11d
--- /dev/null
+++ b/misc-progs/setconsole.c
@@ -0,0 +1,42 @@
+/*
+ * setconsole.c -- choose a console to receive kernel messages
+ *
+ * Copyright (C) 1998,2000,2001 Alessandro Rubini
+ * 
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+
+int main(int argc, char **argv)
+{
+    char bytes[2] = {11,0}; /* 11 is the TIOCLINUX cmd number */
+
+    if (argc==2) bytes[1] = atoi(argv[1]); /* the chosen console */
+    else {
+        fprintf(stderr, "%s: need a single arg\n",argv[0]); exit(1);
+    }
+    if (ioctl(STDIN_FILENO, TIOCLINUX, bytes)<0) {    /* use stdin */
+        fprintf(stderr,"%s: ioctl(stdin, TIOCLINUX): %s\n",
+                argv[0], strerror(errno));
+        exit(1);
+    }
+    exit(0);
+}
diff --git a/misc-progs/setlevel.c b/misc-progs/setlevel.c
new file mode 100644
index 0000000..fec666d
--- /dev/null
+++ b/misc-progs/setlevel.c
@@ -0,0 +1,47 @@
+/*
+ * setlevel.c -- choose a console_loglevel for the kernel
+ *
+ * Copyright (C) 1998,2000,2001 Alessandro Rubini
+ * 
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+/* #include <unistd.h> */ /* conflicting on the alpha */
+#define __LIBRARY__ /* _syscall3 and friends are only available through this */
+#include <linux/unistd.h>
+
+/* define the system call, to override the library function */
+_syscall3(int, syslog, int, type, char *, bufp, int, len);
+
+int main(int argc, char **argv)
+{
+    int level;
+
+    if (argc==2) {
+	level = atoi(argv[1]); /* the chosen console */
+    } else {
+        fprintf(stderr, "%s: need a single arg\n",argv[0]); exit(1);
+    }
+    if (syslog(8,NULL,level) < 0) {  
+        fprintf(stderr,"%s: syslog(setlevel): %s\n",
+                argv[0],strerror(errno));
+        exit(1);
+    }
+    exit(0);
+}