From 1427e4083cd5a9c751f2dc6f1da7b94f6d41e73b Mon Sep 17 00:00:00 2001
From: patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3>
Date: Fri, 12 Sep 2008 15:54:20 +0000
Subject: [PATCH] Add mmap() API
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@916 42af7a65-404d-4744-a932-0658087f49c3
---
ChangeLog | 1 +
Documentation/NuttX.html | 1 +
TODO | 8 +-
fs/Makefile | 2 +-
fs/fs_mmap.c | 171 +++++++++++++++++++++++++++++++++++++++
fs/romfs/fs_romfs.c | 2 +-
include/sys/mman.h | 108 +++++++++++++++++++++++++
7 files changed, 290 insertions(+), 3 deletions(-)
create mode 100644 fs/fs_mmap.c
create mode 100644 include/sys/mman.h
diff --git a/ChangeLog b/ChangeLog
index 80b498c72d..51ccb4012c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -471,5 +471,6 @@
* Add a FIOC_MMAP to perform memory mapping of a file and implemented the
ioctl command in the ROMFS filesystem. This is a requirement for eXecute
In Place (XIP) support.
+ * Add mmap() API with restricted capability (only for XIP support)
diff --git a/Documentation/NuttX.html b/Documentation/NuttX.html
index b1e1b1c7da..b6380ec34f 100644
--- a/Documentation/NuttX.html
+++ b/Documentation/NuttX.html
@@ -1105,6 +1105,7 @@ nuttx-0.3.15 2008-xx-xx Gregory Nutt <spudmonkey@racsa.co.cr>
* Add a FIOC_MMAP to perform memory mapping of a file and implemented the
ioctl command in the ROMFS filesystem. This is a requirement for eXecute
In Place (XIP) support.
+ * Add mmap() API with restricted capability (only for XIP support)
pascal-0.1.3 2008-xx-xx Gregory Nutt <spudmonkey@racsa.co.cr>
diff --git a/TODO b/TODO
index 1fde6da6ff..cc4071b470 100644
--- a/TODO
+++ b/TODO
@@ -10,7 +10,7 @@ NuttX TODO List (Last updated July 31, 2008)
(12) Network (net/, netutils/)
(2) USB (drivers/usbdev)
(3) Libraries (lib/)
- (4) File system/Generic drivers (fs/, drivers/)
+ (5) File system/Generic drivers (fs/, drivers/)
(1) Pascal add-on (pcode/)
(2) Documentation (Documentation/)
(3) Build system
@@ -250,6 +250,12 @@ o File system / Generic drivers (fs/, drivers/)
when there are not open references to the pipe/FIFO.
Priority: Medium
+ Description: The ROMFS file system does not verify checksums on either
+ volume header on on the individual files.
+ Status: Open
+ Priority: Low. I have mixed feelings about if NuttX should pay a
+ performance penalty for better data integrity.
+
o Pascal Add-On (pcode/)
^^^^^^^^^^^^^^^^^^^^^^
diff --git a/fs/Makefile b/fs/Makefile
index 0d08c84aba..d47d1d24b8 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -45,7 +45,7 @@ CSRCS += fs_close.c fs_write.c fs_ioctl.c
endif
else
CSRCS += fs_open.c fs_close.c fs_read.c fs_write.c fs_ioctl.c fs_lseek.c \
- fs_dup.c fs_opendir.c fs_closedir.c fs_stat.c fs_readdir.c \
+ fs_dup.c fs_mmap.c fs_opendir.c fs_closedir.c fs_stat.c fs_readdir.c \
fs_readdirr.c fs_seekdir.c fs_telldir.c fs_rewinddir.c fs_files.c \
fs_inode.c fs_inodefind.c fs_inodereserve.c fs_statfs.c \
fs_inoderemove.c fs_registerdriver.c fs_unregisterdriver.c \
diff --git a/fs/fs_mmap.c b/fs/fs_mmap.c
new file mode 100644
index 0000000000..57ab57fa11
--- /dev/null
+++ b/fs/fs_mmap.c
@@ -0,0 +1,171 @@
+/****************************************************************************
+ * fs/fs_mmap.c
+ *
+ * Copyright (C) 2008 Gregory Nutt. All rights reserved.
+ * Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ * used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <sys/ioctl.h>
+#include <errno.h>
+#include <debug.h>
+
+#include "fs_internal.h"
+
+/****************************************************************************
+ * Global Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: mmap
+ *
+ * Description:
+ * NuttX operates in a flat open address space. Therefore, it generally
+ * does not require mmap() functionality. There is one one exception:
+ * mmap is the API that is used to support direct access to random
+ * access media under the following very restrictive conditions:
+ *
+ * 1. The filesystem supports the FIOC_MMAP ioctl command. Any file system
+ * that maps files contiguously on the media should support this ioctl.
+ * (vs. file system that scatter files over the media in non-contigous
+ * sectors). As of this writing, ROMFS is the only file system that
+ * meets this requirement.
+ * 2. The underly block driver supports the BIOC_XIPBASE ioctl command.
+ * that maps the underlying media to a randomly accessible address. At
+ * present, on the RAM/ROM disk driver does this.
+ *
+ * Parameters:
+ * start A hint at where to map the memory -- ignored. The address
+ * of the underlying media is fixed and cannot be re-mapped with
+ * MMU support.
+ * length The length of the mapping -- ignored. The entire underlying
+ * media is always accessible.
+ * prot See the PROT_* definitions in sys/mman.h.
+ * PROT_NONE - Will cause an error
+ * PROT_READ - PROT_WRITE and PROT_EXEC also assumed
+ * PROT_WRITE - PROT_READ and PROT_EXEC also assumed
+ * PROT_EXEC - PROT_READ and PROT_WRITE also assumed
+ * flags See the MAP_* definitions in sys/mman.h.
+ * MAP_SHARED - Required
+ * MAP_PRIVATE - Will cause an error
+ * MAP_FIXED - Will cause an error
+ * MAP_FILE - Ignored
+ * MAP_ANONYMOUS - Will cause an error
+ * MAP_ANON - Will cause an error
+ * MAP_GROWSDOWN - Ignored
+ * MAP_DENYWRITE - Will cause an error
+ * MAP_EXECUTABLE - Ignored
+ * MAP_LOCKED - Ignored
+ * MAP_NORESERVE - Ignored
+ * MAP_POPULATE - Ignored
+ * MAP_NONBLOCK - Ignored
+ * fd file descriptor of backing file -- required.
+ * offset The offset into the file to map
+ *
+ * Return:
+ * On success, mmap() returns a pointer to the mapped area.
+ * On error, the value MAP_FAILED is returned, and errno is set appropriately.
+ *
+ * ENOSYS
+ * Returned if any of the unsupported mmap() features are attempted
+ * EBADF
+ * 'fd' is not a valid file descriptor.
+ * EINVAL
+ * Length is 0. flags contained neither MAP_PRIVATE or MAP_SHARED, or
+ * contained both of these values.
+ * ENODEV
+ * The underlying filesystem of the specified file does not support
+ * memory mapping.
+ *
+ ****************************************************************************/
+
+FAR void *mmap(FAR void *start, size_t length, int prot, int flags,
+ int fd, off_t offset)
+{
+ FAR void *addr;
+ int ret;
+
+ /* Since only a tiny subset of mmap() functionality, we have to verify many
+ * things.
+ */
+
+#ifdef CONFIG_DEBUG
+ if (prot == PROT_NONE ||
+ (flags & (MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS|MAP_DENYWRITE)) != 0)
+ {
+ fdbg("Unsupported options, prot=%x flags=%04x\n", prot, flags);
+ ret = ENOSYS;
+ goto errout_with_ret;
+ }
+
+ if (length == 0 ||
+ (flags & MAP_SHARED) == 0)
+ {
+ fdbg("Invalid options, lengt=%d flags=%04x\n", length, flags);
+ ret = EINVAL;
+ goto errout_with_ret;
+ }
+#endif
+
+ /* Okay now we can assume a shared mapping from a file. This is the
+ * only option supported
+ *
+ * Perform the ioctl to get the base address of the file in 'mapped'
+ * in memory.
+ */
+
+ ret = ioctl(fd, FIOC_MMAP, (unsigned long)&addr);
+ if (ret < 0)
+ {
+ fdbg("ioctl(FIOC_MMAP) failed: %d\n", errno);
+ goto errout;
+ }
+
+ /* Return the offset address */
+
+ return (void*)(((ubyte*)addr) + offset);
+
+#ifdef CONFIG_DEBUG
+errout_with_ret:
+ errno = ret;
+#endif
+
+errout:
+ return MAP_FAILED;
+}
+
diff --git a/fs/romfs/fs_romfs.c b/fs/romfs/fs_romfs.c
index 4eb9394846..ae4542e401 100644
--- a/fs/romfs/fs_romfs.c
+++ b/fs/romfs/fs_romfs.c
@@ -512,7 +512,7 @@ static int romfs_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
struct romfs_mountpt_s *rm;
struct romfs_file_s *rf;
- void **ppv = (void**)arg;
+ FAR void **ppv = (FAR void**)arg;
/* Sanity checks */
diff --git a/include/sys/mman.h b/include/sys/mman.h
new file mode 100644
index 0000000000..9a140011c8
--- /dev/null
+++ b/include/sys/mman.h
@@ -0,0 +1,108 @@
+/****************************************************************************
+ * include/sys/mman.h
+ *
+ * Copyright (C) 2008 Gregory Nutt. All rights reserved.
+ * Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ * used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#ifndef __SYS_MMAN_H
+#define __SYS_MMAN_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <sys/types.h>
+
+/****************************************************************************
+ * Pre-Processor Definitions
+ ****************************************************************************/
+
+/* Protections are chosen from these bits, OR'd together. NuttX does not
+ * support any of these, but are provided for source level compatibility
+ */
+
+#define PROT_NONE 0x0 /* Page may not be accessed */
+#define PROT_READ 0x1 /* Page may be read */
+#define PROT_WRITE 0x2 /* Page may be written */
+#define PROT_EXEC 0x4 /* Page may be executed */
+
+/* Sharing types -- ignored by NuttX. */
+
+#define MAP_SHARED 0x00001 /* Share this mapping */
+#define MAP_PRIVATE 0x00002 /* Create a private copy-on-write mapping */
+#define MAP_TYPE 0x0000f /* Mask for type of mapping */
+#define MAP_FIXED 0x00010 /* Map to specified address exactly */
+#define MAP_FILE 0x00000 /* The mapping is backed by a file */
+#define MAP_ANONYMOUS 0x00020 /* The mapping is not backed by any file */
+#define MAP_ANON MAP_ANONYMOUS
+
+/* These are Linux-specific. */
+
+#define MAP_GROWSDOWN 0x00100 /* Used to stack allocations */
+#define MAP_DENYWRITE 0x00800 /* Do not permit writes to file */
+#define MAP_EXECUTABLE 0x01000 /* Mark it as an executable */
+#define MAP_LOCKED 0x02000 /* Lock pages mapped into memory */
+#define MAP_NORESERVE 0x04000 /* Do not reserve swap space for this mapping */
+#define MAP_POPULATE 0x08000 /* Populate (prefault) pagetables */
+#define MAP_NONBLOCK 0x10000 /* Do not block on IO */
+
+/* Failure return */
+
+#define MAP_FAILED ((void*)-1)
+
+/****************************************************************************
+ * Public Type Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#undef EXTERN
+#if defined(__cplusplus)
+#define EXTERN extern "C"
+extern "C" {
+#else
+#define EXTERN extern
+#endif
+
+EXTERN FAR void *mmap(FAR void *start, size_t length, int prot, int flags,
+ int fd, off_t offset);
+#define munmap(start, length)
+
+#undef EXTERN
+#if defined(__cplusplus)
+}
+#endif
+
+#endif /* __SYS_MMAN_H */
--
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