first

rt-thread/components/libc/posix/io/mman/SConscript

@@ -0,0 +1,11 @@
+# RT-Thread building script for component
+
+from building import *
+
+cwd     = GetCurrentDir()
+src     = ['mman.c']
+CPPPATH = [cwd]
+
+group = DefineGroup('POSIX', src, depend = ['RT_USING_POSIX_MMAN'], CPPPATH = CPPPATH)
+
+Return('group')

rt-thread/components/libc/posix/io/mman/mman.c

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+/*
+ * Copyright (c) 2006-2021, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author            Notes
+ * 2017/11/30     Bernard           The first version.
+ * 2024/03/29     TroyMitchelle     Add all function comments
+ */
+
+#include <stdint.h>
+#include <stdio.h>
+
+#include <rtthread.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/statfs.h>
+#include <sys/errno.h>
+
+#include "sys/mman.h"
+
+/**
+ * @brief   Maps a region of memory into the calling process's address space.
+ * @param   addr    Desired starting address of the mapping.
+ * @param   length  Length of the mapping.
+ * @param   prot    Protection of the mapped memory region.
+ * @param   flags   Type of the mapped memory region.
+ * @param   fd      File descriptor of the file to be mapped.
+ * @param   offset  Offset within the file to start the mapping.
+ * @return  Upon success, returns a pointer to the mapped region; otherwise, MAP_FAILED is returned.
+ */
+void *mmap(void *addr, size_t length, int prot, int flags,
+    int fd, off_t offset)
+{
+    uint8_t *mem;
+
+    if (addr)
+    {
+        mem = addr;
+    }
+    else mem = (uint8_t *)malloc(length);
+
+    if (mem)
+    {
+        off_t cur;
+        size_t read_bytes;
+
+        cur = lseek(fd, 0, SEEK_SET);
+
+        lseek(fd, offset, SEEK_SET);
+        read_bytes = read(fd, mem, length);
+        if (read_bytes != length)
+        {
+            if (addr == RT_NULL)
+            {
+                /* read failed */
+                free(mem);
+                mem = RT_NULL;
+            }
+        }
+        lseek(fd, cur, SEEK_SET);
+
+        return mem;
+    }
+
+    errno = ENOMEM;
+
+    return MAP_FAILED;
+}
+
+/**
+ * @brief   Unmaps a mapped region of memory.
+ * @param   addr    Starting address of the mapping to be unmapped.
+ * @param   length  Length of the mapping.
+ * @return  Upon success, returns 0; otherwise, -1 is returned.
+ */
+int munmap(void *addr, size_t length)
+{
+    if (addr)
+    {
+        free(addr);
+        return 0;
+    }
+
+    return -1;
+}

rt-thread/components/libc/posix/io/mman/sys/mman.h

@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2006-2021, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author            Notes
+ * 2017/11/30     Bernard           The first version.
+ * 2024/03/29     TroyMitchelle     Add comments for all macros
+ */
+
+#ifndef __SYS_MMAN_H__
+#define __SYS_MMAN_H__
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <sys/types.h>
+
+#define MAP_FAILED     ((void *) -1)
+
+/* mmap flags */
+#define MAP_SHARED     0x01      /**< Share the mapping with other processes. */
+#define MAP_PRIVATE    0x02      /**< Create a private copy-on-write mapping. */
+#define MAP_TYPE       0x0f      /**< Mask for type of mapping. */
+#define MAP_FIXED      0x10      /**< Interpret addr exactly. */
+#define MAP_ANON       0x20      /**< Anonymous mapping. */
+#define MAP_ANONYMOUS  MAP_ANON  /**< Synonym for MAP_ANON. */
+#define MAP_NORESERVE  0x4000    /**< Don't reserve swap space for this mapping. */
+#define MAP_GROWSDOWN  0x0100    /**< Stack-like segment. */
+#define MAP_DENYWRITE  0x0800    /**< ETXTBSY. */
+#define MAP_EXECUTABLE 0x1000    /**< Mark it as an executable. */
+#define MAP_LOCKED     0x2000    /**< Lock the mapping's pages. */
+#define MAP_POPULATE   0x8000    /**< Populate (prefault) pagetables. */
+#define MAP_NONBLOCK   0x10000   /**< Do not block on IO. */
+#define MAP_STACK      0x20000   /**< Allocation is a stack segment. */
+#define MAP_HUGETLB    0x40000   /**< Create a huge page mapping. */
+#define MAP_FILE       0         /**< Compatibility */
+
+/* mmap protections */
+#define PROT_NONE      0         /**< No access. */
+#define PROT_READ      1         /**< Page can be read. */
+#define PROT_WRITE     2         /**< Page can be written. */
+#define PROT_EXEC      4         /**< Page can be executed. */
+#define PROT_GROWSDOWN 0x01000000/**< Extend change to start of growsdown vma (mprotect only). */
+#define PROT_GROWSUP   0x02000000/**< Extend change to start of growsup vma (mprotect only). */
+
+/* msync flags */
+#define MS_ASYNC       1         /**< Perform asynchronous writes. */
+#define MS_INVALIDATE  2         /**< Invalidate mappings after writing. */
+#define MS_SYNC        4         /**< Perform synchronous writes. */
+
+/* mlockall flags */
+#define MCL_CURRENT    1         /**< Lock all pages which are currently mapped into the address space of the process. */
+#define MCL_FUTURE     2         /**< Lock all pages which will become mapped into the address space of the process in the future. */
+#define MCL_ONFAULT    4         /**< Lock all pages which are currently mapped into the address space of the process on access. */
+
+
+void *mmap (void *start, size_t len, int prot, int flags, int fd, off_t off);
+int munmap (void *start, size_t len);
+
+#ifdef __cplusplus
+}
+#endif
+#endif