Add inb, outb and friends,

2 files changed, 148 insertions, 1 deletions

diff --git a/libc/sysdeps/linux/arm/Makefile b/libc/sysdeps/linux/arm/Makefile
index 965a636db..482d84497 100644
--- a/libc/sysdeps/linux/arm/Makefile
+++ b/libc/sysdeps/linux/arm/Makefile
@@ -36,7 +36,7 @@ CRT0_OBJ=$(patsubst %.S,%.o, $(CRT0))
 SSRC=longjmp.S setjmp.S vfork.S
 SOBJS=$(patsubst %.S,%.o, $(SSRC))
 
-CSRC=
+CSRC=ioperm.c
 COBJS=$(patsubst %.c,%.o, $(CSRC))
 
 OBJS=$(SOBJS) $(MOBJ) $(COBJS)
diff --git a/libc/sysdeps/linux/arm/ioperm.c b/libc/sysdeps/linux/arm/ioperm.c
new file mode 100644
index 000000000..d67c04d3b
--- /dev/null
+++ b/libc/sysdeps/linux/arm/ioperm.c
@@ -0,0 +1,147 @@
+/* Copyright (C) 1998, 1999 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Phil Blundell, based on the Alpha version by
+   David Mosberger.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+/* I/O port access on the ARM is something of a fiction.  What we do is to
+   map an appropriate area of /dev/mem into user space so that a program
+   can blast away at the hardware in such a way as to generate I/O cycles
+   on the bus.  To insulate user code from dependencies on particular
+   hardware we don't allow calls to inb() and friends to be inlined, but
+   force them to come through code in here every time.  Performance-critical
+   registers tend to be memory mapped these days so this should be no big
+   problem.  */
+
+/* Once upon a time this file used mprotect to enable and disable
+   access to particular areas of I/O space.  Unfortunately the
+   mprotect syscall also has the side effect of enabling caching for
+   the area affected (this is a kernel limitation).  So we now just
+   enable all the ports all of the time.  */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <ctype.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <sys/types.h>
+#include <sys/mman.h>
+
+#include <asm/page.h>
+#include <sys/sysctl.h>
+
+
+#define IO_BASE			0x7c000000
+#define IO_SHIFT		0
+#define IO_ADDR(port)	(IO_BASE + ((port) << IO_SHIFT))
+
+
+#if 0
+static struct {
+  unsigned long int	base;
+  unsigned long int	io_base;
+  unsigned int		shift;
+  unsigned int		initdone;	/* since all the above could be 0 */
+} io;
+
+
+#define MAX_PORT	0x10000
+int ioperm(unsigned long int from, unsigned long int num, int turn_on)
+{
+  /* this test isn't as silly as it may look like; consider overflows! */
+  if (from >= MAX_PORT || from + num > MAX_PORT)
+    {
+      __set_errno (EINVAL);
+      return -1;
+    }
+
+  if (turn_on)
+    {
+      if (! io.base)
+	{
+	  int fd;
+
+	  fd = open ("/dev/mem", O_RDWR);
+	  if (fd < 0)
+	    return -1;
+
+	  io.base = (unsigned long int) mmap (0, MAX_PORT << io.shift, 
+					PROT_READ | PROT_WRITE, 
+					MAP_SHARED, fd, io.io_base);
+	  close (fd);
+	  if ((long) io.base == -1)
+	    return -1;
+	}
+    }
+
+  return 0;
+}
+
+
+int iopl (unsigned int level)
+{
+    if (level > 3)
+      {
+	__set_errno (EINVAL);
+	return -1;
+      }
+    if (level)
+      {
+	return _ioperm (0, MAX_PORT, 1);
+      }
+    return 0;
+}
+#endif
+
+void outb (unsigned char b, unsigned long int port)
+{
+  *((volatile unsigned char *)(IO_ADDR (port))) = b;
+}
+
+
+void outw (unsigned short b, unsigned long int port)
+{
+  *((volatile unsigned short *)(IO_ADDR (port))) = b;
+}
+
+
+void outl (unsigned int b, unsigned long int port)
+{
+  *((volatile unsigned long *)(IO_ADDR (port))) = b;
+}
+
+
+unsigned int inb (unsigned long int port)
+{
+  return *((volatile unsigned char *)(IO_ADDR (port)));
+}
+
+
+unsigned int inw (unsigned long int port)
+{
+  return *((volatile unsigned short *)(IO_ADDR (port)));
+}
+
+
+unsigned int inl (unsigned long int port)
+{
+  return *((volatile unsigned long *)(IO_ADDR (port)));
+}
+