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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 */
/** */
/** Utility */
/** */
/**************************************************************************/
/**************************************************************************/
#define FX_SOURCE_CODE
/* Include necessary system files. */
#include "fx_api.h"
#ifdef FX_ENABLE_EXFAT
#include "fx_system.h"
#include "fx_media.h"
#include "fx_utility.h"
#include "fx_directory_exFAT.h"
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _fx_utility_exFAT_bitmap_cache_update PORTABLE C */
/* 6.1 */
/* AUTHOR */
/* */
/* William E. Lamie, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function reads parts of exFAT bitmap to cache. */
/* */
/* INPUT */
/* */
/* media_ptr Media control block pointer */
/* cluster Cluster number */
/* */
/* OUTPUT */
/* */
/* return status */
/* */
/* CALLS */
/* */
/* Media driver */
/* */
/* CALLED BY */
/* */
/* FileX System Functions */
/* */
/* 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 _fx_utility_exFAT_bitmap_cache_update(FX_MEDIA *media_ptr, ULONG cluster)
{
/* Read exFAT bitmap to cache. */
cluster -= FX_FAT_ENTRY_START;
media_ptr -> fx_media_driver_request = FX_DRIVER_READ;
media_ptr -> fx_media_driver_buffer = (UCHAR *)media_ptr -> fx_media_exfat_bitmap_cache;
media_ptr -> fx_media_driver_logical_sector = media_ptr -> fx_media_exfat_bitmap_start_sector +
(cluster >> media_ptr -> fx_media_exfat_bitmap_clusters_per_sector_shift);
media_ptr -> fx_media_driver_sectors = media_ptr -> fx_media_exfat_bitmap_cache_size_in_sectors;
media_ptr -> fx_media_driver_status = FX_IO_ERROR;
/* Invoke the driver to read the FAT sectors. */
(media_ptr -> fx_media_driver_entry)(media_ptr);
/* Calculate new cached clusters. */
media_ptr -> fx_media_exfat_bitmap_cache_start_cluster =
(ULONG)((media_ptr -> fx_media_driver_logical_sector - media_ptr -> fx_media_exfat_bitmap_start_sector) <<
media_ptr -> fx_media_exfat_bitmap_clusters_per_sector_shift) +
FX_FAT_ENTRY_START;
media_ptr -> fx_media_exfat_bitmap_cache_end_cluster = media_ptr -> fx_media_exfat_bitmap_cache_start_cluster +
((media_ptr -> fx_media_exfat_bitmap_cache_size_in_sectors << media_ptr -> fx_media_exfat_bytes_per_sector_shift) <<
BITS_PER_BYTE_SHIFT) - 1;
/* Return driver status. */
return(media_ptr -> fx_media_driver_status);
}
#endif /* FX_ENABLE_EXFAT */
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