1 /***************************************************************************
2 * Copyright (c) 2024 Microsoft Corporation
3 *
4 * This program and the accompanying materials are made available under the
5 * terms of the MIT License which is available at
6 * https://opensource.org/licenses/MIT.
7 *
8 * SPDX-License-Identifier: MIT
9 **************************************************************************/
10
11
12 /**************************************************************************/
13 /**************************************************************************/
14 /** */
15 /** FileX Component */
16 /** */
17 /** Fault Tolerant */
18 /** */
19 /**************************************************************************/
20 /**************************************************************************/
21
22 #define FX_SOURCE_CODE
23
24 #include "fx_api.h"
25 #include "fx_utility.h"
26 #include "fx_fault_tolerant.h"
27
28
29 #ifdef FX_ENABLE_FAULT_TOLERANT
30 /**************************************************************************/
31 /* */
32 /* FUNCTION RELEASE */
33 /* */
34 /* _fx_fault_tolerant_set_FAT_chain PORTABLE C */
35 /* 6.1 */
36 /* AUTHOR */
37 /* */
38 /* William E. Lamie, Microsoft Corporation */
39 /* */
40 /* DESCRIPTION */
41 /* */
42 /* This function sets data of FAT chain. */
43 /* */
44 /* INPUT */
45 /* */
46 /* media_ptr Media control block pointer */
47 /* use_bitmap Whether or not the orignal */
48 /* FAT chain uses bitmap */
49 /* insertion_front Previous cluster of head */
50 /* new_head_cluster Head cluster of new chain */
51 /* origianl_head_cluster Head cluster of the original */
52 /* chain */
53 /* insertion_back next cluster of chain tail */
54 /* */
55 /* OUTPUT */
56 /* */
57 /* return status */
58 /* */
59 /* CALLS */
60 /* */
61 /* _fx_utility_16_unsigned_write Write a USHORT from memory */
62 /* _fx_utility_32_unsigned_write Write a ULONG from memory */
63 /* _fx_fault_tolerant_calculate_checksum Compute Checksum of data */
64 /* _fx_fault_tolerant_write_log_file Write log file */
65 /* */
66 /* CALLED BY */
67 /* */
68 /* _fx_file_allocate */
69 /* _fx_file_best_effort_allocate */
70 /* _fx_file_delete */
71 /* _fx_file_truncate_release */
72 /* _fx_file_write */
73 /* */
74 /* RELEASE HISTORY */
75 /* */
76 /* DATE NAME DESCRIPTION */
77 /* */
78 /* 05-19-2020 William E. Lamie Initial Version 6.0 */
79 /* 09-30-2020 William E. Lamie Modified comment(s), */
80 /* resulting in version 6.1 */
81 /* */
82 /**************************************************************************/
_fx_fault_tolerant_set_FAT_chain(FX_MEDIA * media_ptr,UINT use_bitmap,ULONG insertion_front,ULONG new_head_cluster,ULONG original_head_cluster,ULONG insertion_back)83 UINT _fx_fault_tolerant_set_FAT_chain(FX_MEDIA *media_ptr, UINT use_bitmap, ULONG insertion_front,
84 ULONG new_head_cluster, ULONG original_head_cluster,
85 ULONG insertion_back)
86 {
87 UINT status;
88 USHORT checksum;
89 UCHAR flag = FX_FAULT_TOLERANT_FLAG_FAT_CHAIN_VALID;
90 FX_FAULT_TOLERANT_FAT_CHAIN *FAT_chain;
91
92 /* Set FAT chain pointer. */
93 FAT_chain = (FX_FAULT_TOLERANT_FAT_CHAIN *)(media_ptr -> fx_media_fault_tolerant_memory_buffer + FX_FAULT_TOLERANT_FAT_CHAIN_OFFSET);
94
95 /* Parameters not used. Avoid compiler warnings. */
96 FX_PARAMETER_NOT_USED(use_bitmap);
97
98
99 /* Reset checksum first. */
100 _fx_utility_16_unsigned_write((UCHAR *)&FAT_chain -> fx_fault_tolerant_FAT_chain_checksumm, 0);
101
102 /* Set clusters. */
103 _fx_utility_32_unsigned_write((UCHAR *)&FAT_chain -> fx_fault_tolerant_FAT_chain_insertion_front, insertion_front);
104 _fx_utility_32_unsigned_write((UCHAR *)&FAT_chain -> fx_fault_tolerant_FAT_chain_head_new, new_head_cluster);
105 _fx_utility_32_unsigned_write((UCHAR *)&FAT_chain -> fx_fault_tolerant_FAT_chain_head_original, original_head_cluster);
106 _fx_utility_32_unsigned_write((UCHAR *)&FAT_chain -> fx_fault_tolerant_FAT_chain_insertion_back, insertion_back);
107 _fx_utility_32_unsigned_write((UCHAR *)&FAT_chain -> fx_fault_tolerant_FAT_chain_next_deletion, FX_FREE_CLUSTER);
108
109 /* Set flag and reserved. */
110 FAT_chain -> fx_fault_tolerant_FAT_chain_flag = flag;
111 FAT_chain -> fx_fault_tolerant_FAT_chain_reserved = (UCHAR)0;
112
113 /* Calculate checksum. */
114 checksum = _fx_fault_tolerant_calculate_checksum((UCHAR *)FAT_chain, FX_FAULT_TOLERANT_FAT_CHAIN_SIZE);
115 _fx_utility_16_unsigned_write((UCHAR *)&FAT_chain -> fx_fault_tolerant_FAT_chain_checksumm, checksum);
116
117 /* Write the log header and FAT chain. */
118 status = _fx_fault_tolerant_write_log_file(media_ptr, 0);
119
120 /* Return the status. */
121 return(status);
122 }
123 #endif /* FX_ENABLE_FAULT_TOLERANT */
124
125
