1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
|
/* $Id: biossums.c $ */
/** @file
* Tool for modifying a BIOS image to write the BIOS checksum.
*/
/*
* Copyright (C) 2006-2019 Oracle Corporation
*
* This file is part of VirtualBox Open Source Edition (OSE), as
* available from http://www.virtualbox.org. This file is free software;
* you can redistribute it and/or modify it under the terms of the GNU
* General Public License (GPL) as published by the Free Software
* Foundation, in version 2 as it comes in the "COPYING" file of the
* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#include <errno.h>
#ifndef RT_OS_WINDOWS
# include <unistd.h> /* unlink */
#endif
typedef unsigned char uint8_t;
static uint8_t abBios[64*1024];
static FILE *g_pIn = NULL;
static FILE *g_pOut = NULL;
static const char *g_pszOutFile = NULL;
static const char *g_argv0;
/**
* Find where the filename starts in the given path.
*/
static const char *name(const char *pszPath)
{
const char *psz = strrchr(pszPath, '/');
#if defined(_MSC_VER) || defined(__OS2__)
const char *psz2 = strrchr(pszPath, '\\');
if (!psz2)
psz2 = strrchr(pszPath, ':');
if (psz2 && (!psz || psz2 > psz))
psz = psz2;
#endif
return psz ? psz + 1 : pszPath;
}
/**
* Report an error.
*/
static int fatal(const char *pszFormat, ...)
{
va_list va;
fprintf(stderr, "%s: ", name(g_argv0));
va_start(va, pszFormat);
vfprintf(stderr, pszFormat, va);
va_end(va);
/* clean up */
if (g_pIn)
fclose(g_pIn);
if (g_pOut)
fclose(g_pOut);
if (g_pszOutFile)
unlink(g_pszOutFile);
return 1;
}
/**
* Calculate the checksum.
*/
static uint8_t calculateChecksum(uint8_t *pb, size_t cb, size_t iChecksum)
{
uint8_t u8Sum = 0;
size_t i;
for (i = 0; i < cb; i++)
if (i != iChecksum)
u8Sum += pb[i];
return -u8Sum;
}
/**
* Find a header in the binary.
*
* @param pb Where to search for the signature
* @param cb Size of the search area
* @param pbHeader Pointer to the start of the signature
* @returns 0 if signature was not found, 1 if found or
* 2 if more than one signature was found */
static int searchHeader(uint8_t *pb, size_t cb, const char *pszHeader, uint8_t **pbHeader)
{
int fFound = 0;
unsigned int i;
size_t cbSignature = strlen(pszHeader);
for (i = 0; i < cb; i += 16)
if (!memcmp(pb + i, pszHeader, cbSignature))
{
if (fFound++)
return 2;
*pbHeader = pb + i;
}
return fFound;
}
int main(int argc, char **argv)
{
FILE *pIn, *pOut;
size_t cbIn, cbOut;
int fAdapterBios = 0;
g_argv0 = argv[0];
if (argc != 3)
return fatal("Input file name and output file name required.\n");
pIn = g_pIn = fopen(argv[1], "rb");
if (!pIn)
return fatal("Error opening '%s' for reading (%s).\n", argv[1], strerror(errno));
pOut = g_pOut = fopen(argv[2], "wb");
if (!pOut)
return fatal("Error opening '%s' for writing (%s).\n", argv[2], strerror(errno));
g_pszOutFile = argv[2];
/* safety precaution (aka. complete paranoia :-) */
memset(abBios, 0, sizeof(abBios));
cbIn = fread(abBios, 1, sizeof(abBios), pIn);
if (ferror(pIn))
return fatal("Error reading from '%s' (%s).\n", argv[1], strerror(errno));
g_pIn = NULL;
fclose(pIn);
fAdapterBios = abBios[0] == 0x55 && abBios[1] == 0xaa;
/* align size to page size */
if ((cbIn % 4096) != 0)
cbIn = (cbIn + 4095) & ~4095;
if (!fAdapterBios && cbIn != 64*1024)
return fatal("Size of system BIOS is not 64KB!\n");
if (fAdapterBios)
{
/* adapter BIOS */
/* set the length indicator */
abBios[2] = (uint8_t)(cbIn / 512);
}
else
{
/* system BIOS */
size_t cbChecksum;
uint8_t u8Checksum;
uint8_t *pbHeader;
/* Set the BIOS32 header checksum. */
switch (searchHeader(abBios, cbIn, "_32_", &pbHeader))
{
case 0:
return fatal("No BIOS32 header not found!\n");
case 2:
return fatal("More than one BIOS32 header found!\n");
case 1:
cbChecksum = (size_t)pbHeader[9] * 16;
u8Checksum = calculateChecksum(pbHeader, cbChecksum, 10);
pbHeader[10] = u8Checksum;
break;
}
/* Set the PIR header checksum according to PCI IRQ Routing table
* specification version 1.0, Microsoft Corporation, 1996 */
switch (searchHeader(abBios, cbIn, "$PIR", &pbHeader))
{
case 0:
return fatal("No PCI IRQ routing table found!\n");
case 2:
return fatal("More than one PCI IRQ routing table found!\n");
case 1:
cbChecksum = (size_t)pbHeader[6] + (size_t)pbHeader[7] * 256;
u8Checksum = calculateChecksum(pbHeader, cbChecksum, 31);
pbHeader[31] = u8Checksum;
break;
}
/* Set the SMBIOS header checksum according to System Management BIOS
* Reference Specification Version 2.5, DSP0134. */
switch (searchHeader(abBios, cbIn, "_SM_", &pbHeader))
{
case 0:
return fatal("No SMBIOS header found!\n");
case 2:
return fatal("More than one SMBIOS header found!\n");
case 1:
/* at first fix the DMI header starting at SMBIOS header offset 16 */
u8Checksum = calculateChecksum(pbHeader+16, 15, 5);
pbHeader[21] = u8Checksum;
/* now fix the checksum of the whole SMBIOS header */
cbChecksum = (size_t)pbHeader[5];
u8Checksum = calculateChecksum(pbHeader, cbChecksum, 4);
pbHeader[4] = u8Checksum;
break;
}
}
/* set the BIOS checksum */
abBios[cbIn-1] = calculateChecksum(abBios, cbIn, cbIn - 1);
cbOut = fwrite(abBios, 1, cbIn, pOut);
if (ferror(pOut))
return fatal("Error writing to '%s' (%s).\n", g_pszOutFile, strerror(errno));
g_pOut = NULL;
if (fclose(pOut))
return fatal("Error closing '%s' (%s).\n", g_pszOutFile, strerror(errno));
return 0;
}
|
