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/**************************************************************************/ |
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/* */ |
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/* Copyright (c) Microsoft Corporation. All rights reserved. */ |
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/* */ |
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/* This software is licensed under the Microsoft Software License */ |
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/* Terms for Microsoft Azure RTOS. Full text of the license can be */ |
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/* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */ |
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/* and in the root directory of this software. */ |
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/* */ |
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/**************************************************************************/ |
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/**************************************************************************/ |
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/**************************************************************************/ |
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/** */ |
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/** FileX Component */ |
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/** */ |
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/** Utility */ |
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/** */ |
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/**************************************************************************/ |
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/**************************************************************************/ |
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#define FX_SOURCE_CODE |
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/* Include necessary system files. */ |
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#include "fx_api.h" |
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#include "fx_utility.h" |
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/**************************************************************************/ |
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/* */ |
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/* FUNCTION RELEASE */ |
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/* */ |
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/* _fx_utility_FAT_sector_get PORTABLE C */ |
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/* 6.1 */ |
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/* AUTHOR */ |
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/* */ |
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/* William E. Lamie, Microsoft Corporation */ |
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/* */ |
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/* DESCRIPTION */ |
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/* */ |
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/* This function gets the sector of supplied FAT entry. */ |
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/* */ |
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/* INPUT */ |
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/* */ |
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/* media_ptr Media control block pointer */ |
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/* cluster Cluster entry number */ |
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/* */ |
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/* OUTPUT */ |
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/* */ |
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/* return sector of FAT entry */ |
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/* */ |
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/* CALLS */ |
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/* */ |
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/* */ |
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/* CALLED BY */ |
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/* */ |
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/* FileX System Functions */ |
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/* */ |
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/* RELEASE HISTORY */ |
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/* */ |
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/* DATE NAME DESCRIPTION */ |
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/* */ |
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/* 05-19-2020 William E. Lamie Initial Version 6.0 */ |
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/* 09-30-2020 William E. Lamie Modified comment(s), */ |
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/* resulting in version 6.1 */ |
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/* */ |
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/**************************************************************************/ |
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ULONG _fx_utility_FAT_sector_get(FX_MEDIA *media_ptr, ULONG cluster) |
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{ |
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ULONG FAT_sector; |
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ULONG byte_offset; |
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/* Determine which type of FAT is present. */ |
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#ifdef FX_ENABLE_EXFAT |
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if (media_ptr -> fx_media_FAT_type == FX_FAT12) |
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#else |
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✓✓ |
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if (media_ptr -> fx_media_12_bit_FAT) |
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#endif /* FX_ENABLE_EXFAT */ |
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{ |
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/* 12-bit FAT is present. */ |
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/* Calculate the byte offset to the cluster entry. */ |
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byte_offset = (((ULONG)cluster << 1) + cluster) >> 1; |
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} |
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#ifdef FX_ENABLE_EXFAT |
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else if (media_ptr -> fx_media_FAT_type == FX_FAT16) |
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#else |
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✓✓ |
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else if (!media_ptr -> fx_media_32_bit_FAT) |
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#endif /* FX_ENABLE_EXFAT */ |
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{ |
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/* 16-bit FAT is present. */ |
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/* Calculate the byte offset to the cluster entry. */ |
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byte_offset = (((ULONG)cluster) << 1); |
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} |
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else |
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{ |
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/* 32-bit FAT or exFAT are present. */ |
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/* Calculate the byte offset to the cluster entry. */ |
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byte_offset = (((ULONG)cluster) * 4); |
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} |
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/* Calculate the FAT sector the requested FAT entry resides in. */ |
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FAT_sector = (byte_offset / media_ptr -> fx_media_bytes_per_sector) + |
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(ULONG)media_ptr -> fx_media_reserved_sectors; |
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/* Return successful status. */ |
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return(FAT_sector); |
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} |
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