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/**************************************************************************/
/* */
/* Copyright (c) Microsoft Corporation. All rights reserved. */
/* */
/* This software is licensed under the Microsoft Software License */
/* Terms for Microsoft Azure RTOS. Full text of the license can be */
/* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
/* and in the root directory of this software. */
/* */
/**************************************************************************/
/**************************************************************************/
/**************************************************************************/
/** */
/** FileX Component */
/** */
/** File */
/** */
/**************************************************************************/
/**************************************************************************/
#define FX_SOURCE_CODE
/* Include necessary system files. */
#include "fx_api.h"
#include "fx_file.h"
FX_CALLER_CHECKING_EXTERNS
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _fxe_file_open PORTABLE C */
/* 6.1 */
/* AUTHOR */
/* */
/* William E. Lamie, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function checks for errors in the file open call. */
/* */
/* INPUT */
/* */
/* media_ptr Media control block pointer */
/* file_ptr File control block pointer */
/* file_name Name pointer */
/* open_type Type of open requested */
/* file_control_block_size Size of FX_FILE structure */
/* */
/* OUTPUT */
/* */
/* return status */
/* */
/* CALLS */
/* */
/* _fx_file_open Actual open file service */
/* */
/* CALLED BY */
/* */
/* Application Code */
/* */
/* RELEASE HISTORY */
/* */
/* DATE NAME DESCRIPTION */
/* */
/* 05-19-2020 William E. Lamie Initial Version 6.0 */
/* 09-30-2020 William E. Lamie Modified comment(s), */
/* resulting in version 6.1 */
/* */
/**************************************************************************/
UINT _fxe_file_open(FX_MEDIA *media_ptr, FX_FILE *file_ptr, CHAR *file_name, UINT open_type, UINT file_control_block_size)
{
UINT status;
FX_FILE *current_file;
ULONG open_count;
/* Check for a null media or file pointer. */
if ((media_ptr == FX_NULL) || (media_ptr -> fx_media_id != FX_MEDIA_ID) || (file_ptr == FX_NULL) || (file_control_block_size != sizeof(FX_FILE)))
{
return(FX_PTR_ERROR);
}
/* Check for an invalid open type. */
if ((open_type != FX_OPEN_FOR_READ) && (open_type != FX_OPEN_FOR_READ_FAST) && (open_type != FX_OPEN_FOR_WRITE))
{
return(FX_ACCESS_ERROR);
}
/* Check for a valid caller. */
FX_CALLER_CHECKING_CODE
/* Get protection. */
FX_PROTECT
/* Check for a duplicate file open. */
/* Loop to search the list for the same file handle. */
current_file = media_ptr -> fx_media_opened_file_list;
open_count = media_ptr -> fx_media_opened_file_count;
while (open_count--)
{
/* See if a match exists. */
if (file_ptr == current_file)
{
/* Release protection. */
FX_UNPROTECT
/* Return error. */
return(FX_PTR_ERROR);
}
/* Move to the next opened file. */
current_file = current_file -> fx_file_opened_next;
}
/* Release protection. */
FX_UNPROTECT
/* Call actual file open service. */
status = _fx_file_open(media_ptr, file_ptr, file_name, open_type);
/* Open is complete, return status. */
return(status);
}