1/******************************************************************************
2 *
3 * Module Name: utcksum - Support generating table checksums
4 *
5 *****************************************************************************/
6
7/******************************************************************************
8 *
9 * 1. Copyright Notice
10 *
11 * Some or all of this work - Copyright (c) 1999 - 2023, Intel Corp.
12 * All rights reserved.
13 *
14 * 2. License
15 *
16 * 2.1. This is your license from Intel Corp. under its intellectual property
17 * rights. You may have additional license terms from the party that provided
18 * you this software, covering your right to use that party's intellectual
19 * property rights.
20 *
21 * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a
22 * copy of the source code appearing in this file ("Covered Code") an
23 * irrevocable, perpetual, worldwide license under Intel's copyrights in the
24 * base code distributed originally by Intel ("Original Intel Code") to copy,
25 * make derivatives, distribute, use and display any portion of the Covered
26 * Code in any form, with the right to sublicense such rights; and
27 *
28 * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent
29 * license (with the right to sublicense), under only those claims of Intel
30 * patents that are infringed by the Original Intel Code, to make, use, sell,
31 * offer to sell, and import the Covered Code and derivative works thereof
32 * solely to the minimum extent necessary to exercise the above copyright
33 * license, and in no event shall the patent license extend to any additions
34 * to or modifications of the Original Intel Code. No other license or right
35 * is granted directly or by implication, estoppel or otherwise;
36 *
37 * The above copyright and patent license is granted only if the following
38 * conditions are met:
39 *
40 * 3. Conditions
41 *
42 * 3.1. Redistribution of Source with Rights to Further Distribute Source.
43 * Redistribution of source code of any substantial portion of the Covered
44 * Code or modification with rights to further distribute source must include
45 * the above Copyright Notice, the above License, this list of Conditions,
46 * and the following Disclaimer and Export Compliance provision. In addition,
47 * Licensee must cause all Covered Code to which Licensee contributes to
48 * contain a file documenting the changes Licensee made to create that Covered
49 * Code and the date of any change. Licensee must include in that file the
50 * documentation of any changes made by any predecessor Licensee. Licensee
51 * must include a prominent statement that the modification is derived,
52 * directly or indirectly, from Original Intel Code.
53 *
54 * 3.2. Redistribution of Source with no Rights to Further Distribute Source.
55 * Redistribution of source code of any substantial portion of the Covered
56 * Code or modification without rights to further distribute source must
57 * include the following Disclaimer and Export Compliance provision in the
58 * documentation and/or other materials provided with distribution. In
59 * addition, Licensee may not authorize further sublicense of source of any
60 * portion of the Covered Code, and must include terms to the effect that the
61 * license from Licensee to its licensee is limited to the intellectual
62 * property embodied in the software Licensee provides to its licensee, and
63 * not to intellectual property embodied in modifications its licensee may
64 * make.
65 *
66 * 3.3. Redistribution of Executable. Redistribution in executable form of any
67 * substantial portion of the Covered Code or modification must reproduce the
68 * above Copyright Notice, and the following Disclaimer and Export Compliance
69 * provision in the documentation and/or other materials provided with the
70 * distribution.
71 *
72 * 3.4. Intel retains all right, title, and interest in and to the Original
73 * Intel Code.
74 *
75 * 3.5. Neither the name Intel nor any other trademark owned or controlled by
76 * Intel shall be used in advertising or otherwise to promote the sale, use or
77 * other dealings in products derived from or relating to the Covered Code
78 * without prior written authorization from Intel.
79 *
80 * 4. Disclaimer and Export Compliance
81 *
82 * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED
83 * HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE
84 * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE,
85 * INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY
86 * UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY
87 * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A
88 * PARTICULAR PURPOSE.
89 *
90 * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES
91 * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR
92 * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT,
93 * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY
94 * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL
95 * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS
96 * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY
97 * LIMITED REMEDY.
98 *
99 * 4.3. Licensee shall not export, either directly or indirectly, any of this
100 * software or system incorporating such software without first obtaining any
101 * required license or other approval from the U. S. Department of Commerce or
102 * any other agency or department of the United States Government. In the
103 * event Licensee exports any such software from the United States or
104 * re-exports any such software from a foreign destination, Licensee shall
105 * ensure that the distribution and export/re-export of the software is in
106 * compliance with all laws, regulations, orders, or other restrictions of the
107 * U.S. Export Administration Regulations. Licensee agrees that neither it nor
108 * any of its subsidiaries will export/re-export any technical data, process,
109 * software, or service, directly or indirectly, to any country for which the
110 * United States government or any agency thereof requires an export license,
111 * other governmental approval, or letter of assurance, without first obtaining
112 * such license, approval or letter.
113 *
114 *****************************************************************************
115 *
116 * Alternatively, you may choose to be licensed under the terms of the
117 * following license:
118 *
119 * Redistribution and use in source and binary forms, with or without
120 * modification, are permitted provided that the following conditions
121 * are met:
122 * 1. Redistributions of source code must retain the above copyright
123 *    notice, this list of conditions, and the following disclaimer,
124 *    without modification.
125 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
126 *    substantially similar to the "NO WARRANTY" disclaimer below
127 *    ("Disclaimer") and any redistribution must be conditioned upon
128 *    including a substantially similar Disclaimer requirement for further
129 *    binary redistribution.
130 * 3. Neither the names of the above-listed copyright holders nor the names
131 *    of any contributors may be used to endorse or promote products derived
132 *    from this software without specific prior written permission.
133 *
134 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
135 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
136 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
137 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
138 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
139 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
140 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
141 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
142 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
143 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
144 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
145 *
146 * Alternatively, you may choose to be licensed under the terms of the
147 * GNU General Public License ("GPL") version 2 as published by the Free
148 * Software Foundation.
149 *
150 *****************************************************************************/
151
152#include "acpi.h"
153#include "accommon.h"
154#include "acdisasm.h"
155#include "acutils.h"
156
157
158/* This module used for application-level code only */
159
160#define _COMPONENT          ACPI_CA_DISASSEMBLER
161        ACPI_MODULE_NAME    ("utcksum")
162
163
164/*******************************************************************************
165 *
166 * FUNCTION:    AcpiUtVerifyChecksum
167 *
168 * PARAMETERS:  Table               - ACPI table to verify
169 *              Length              - Length of entire table
170 *
171 * RETURN:      Status
172 *
173 * DESCRIPTION: Verifies that the table checksums to zero. Optionally returns
174 *              exception on bad checksum.
175 *              Note: We don't have to check for a CDAT here, since CDAT is
176 *              not in the RSDT/XSDT, and the CDAT table is never installed
177 *              via ACPICA.
178 *
179 ******************************************************************************/
180
181ACPI_STATUS
182AcpiUtVerifyChecksum (
183    ACPI_TABLE_HEADER       *Table,
184    UINT32                  Length)
185{
186    UINT8                   Checksum;
187
188
189    /*
190     * FACS/S3PT:
191     * They are the odd tables, have no standard ACPI header and no checksum
192     */
193    if (ACPI_COMPARE_NAMESEG (Table->Signature, ACPI_SIG_S3PT) ||
194        ACPI_COMPARE_NAMESEG (Table->Signature, ACPI_SIG_FACS))
195    {
196        return (AE_OK);
197    }
198
199    /* Compute the checksum on the table */
200
201    Length = Table->Length;
202    Checksum = AcpiUtGenerateChecksum (ACPI_CAST_PTR (UINT8, Table), Length, Table->Checksum);
203
204    /* Computed checksum matches table? */
205
206    if (Checksum != Table->Checksum)
207    {
208        ACPI_BIOS_WARNING ((AE_INFO,
209            "Incorrect checksum in table [%4.4s] - 0x%2.2X, "
210            "should be 0x%2.2X",
211            Table->Signature, Table->Checksum,
212            Table->Checksum - Checksum));
213
214#if (ACPI_CHECKSUM_ABORT)
215        return (AE_BAD_CHECKSUM);
216#endif
217    }
218
219    return (AE_OK);
220}
221
222
223/*******************************************************************************
224 *
225 * FUNCTION:    AcpiUtVerifyCdatChecksum
226 *
227 * PARAMETERS:  Table               - CDAT ACPI table to verify
228 *              Length              - Length of entire table
229 *
230 * RETURN:      Status
231 *
232 * DESCRIPTION: Verifies that the CDAT table checksums to zero. Optionally
233 *              returns an exception on bad checksum.
234 *
235 ******************************************************************************/
236
237ACPI_STATUS
238AcpiUtVerifyCdatChecksum (
239    ACPI_TABLE_CDAT         *CdatTable,
240    UINT32                  Length)
241{
242    UINT8                   Checksum;
243
244
245    /* Compute the checksum on the table */
246
247    Checksum = AcpiUtGenerateChecksum (ACPI_CAST_PTR (UINT8, CdatTable),
248                    CdatTable->Length, CdatTable->Checksum);
249
250    /* Computed checksum matches table? */
251
252    if (Checksum != CdatTable->Checksum)
253    {
254        ACPI_BIOS_WARNING ((AE_INFO,
255            "Incorrect checksum in table [%4.4s] - 0x%2.2X, "
256            "should be 0x%2.2X",
257            AcpiGbl_CDAT, CdatTable->Checksum, Checksum));
258
259#if (ACPI_CHECKSUM_ABORT)
260        return (AE_BAD_CHECKSUM);
261#endif
262    }
263
264    CdatTable->Checksum = Checksum;
265    return (AE_OK);
266}
267
268
269/*******************************************************************************
270 *
271 * FUNCTION:    AcpiUtGenerateChecksum
272 *
273 * PARAMETERS:  Table               - Pointer to table to be checksummed
274 *              Length              - Length of the table
275 *              OriginalChecksum    - Value of the checksum field
276 *
277 * RETURN:      8 bit checksum of buffer
278 *
279 * DESCRIPTION: Computes an 8 bit checksum of the table.
280 *
281 ******************************************************************************/
282
283UINT8
284AcpiUtGenerateChecksum (
285    void                    *Table,
286    UINT32                  Length,
287    UINT8                   OriginalChecksum)
288{
289    UINT8                   Checksum;
290
291
292    /* Sum the entire table as-is */
293
294    Checksum = AcpiUtChecksum ((UINT8 *) Table, Length);
295
296    /* Subtract off the existing checksum value in the table */
297
298    Checksum = (UINT8) (Checksum - OriginalChecksum);
299
300    /* Compute and return the final checksum */
301
302    Checksum = (UINT8) (0 - Checksum);
303    return (Checksum);
304}
305
306
307/*******************************************************************************
308 *
309 * FUNCTION:    AcpiUtChecksum
310 *
311 * PARAMETERS:  Buffer          - Pointer to memory region to be checked
312 *              Length          - Length of this memory region
313 *
314 * RETURN:      Checksum (UINT8)
315 *
316 * DESCRIPTION: Calculates circular checksum of memory region.
317 *
318 ******************************************************************************/
319
320UINT8
321AcpiUtChecksum (
322    UINT8                   *Buffer,
323    UINT32                  Length)
324{
325    UINT8                   Sum = 0;
326    UINT8                   *End = Buffer + Length;
327
328
329    while (Buffer < End)
330    {
331        Sum = (UINT8) (Sum + *(Buffer++));
332    }
333
334    return (Sum);
335}
336