diff options
Diffstat (limited to 'src/bldprogs/biossums.c')
| -rw-r--r-- | src/bldprogs/biossums.c | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/src/bldprogs/biossums.c b/src/bldprogs/biossums.c new file mode 100644 index 00000000..871c55ae --- /dev/null +++ b/src/bldprogs/biossums.c @@ -0,0 +1,255 @@ +/* $Id: biossums.c $ */ +/** @file + * Tool for modifying a BIOS image to write the BIOS checksum. + */ + +/* + * Copyright (C) 2006-2022 Oracle and/or its affiliates. + * + * This file is part of VirtualBox base platform packages, as + * available from https://www.virtualbox.org. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, in version 3 of the + * License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <https://www.gnu.org/licenses>. + * + * SPDX-License-Identifier: GPL-3.0-only + */ + +#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; + } + + /* If there is a VPD table, adjust its checksum. */ + switch (searchHeader(abBios, cbIn, "\xAA\x55VPD", &pbHeader)) + { + case 0: + break; /* VPD is optional */ + case 2: + return fatal("More than one VPD header found!\n"); + case 1: + cbChecksum = (size_t)pbHeader[5]; + if (cbChecksum < 0x30) + return fatal("VPD size too small!\n"); + u8Checksum = calculateChecksum(pbHeader, cbChecksum, cbChecksum - 1); + pbHeader[cbChecksum - 1] = 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; +} + |