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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 | // SPDX-License-Identifier: GPL-2.0+ /* * Copyright (C) 2020, Bachmann electronic GmbH */ #define LOG_CATEGORY LOGC_BOOT #include <common.h> #include <smbios.h> static inline int verify_checksum(const struct smbios_entry *e) { /* * Checksums for SMBIOS tables are calculated to have a value, so that * the sum over all bytes yields zero (using unsigned 8 bit arithmetic). */ u8 *byte = (u8 *)e; u8 sum = 0; for (int i = 0; i < e->length; i++) sum += byte[i]; return sum; } const struct smbios_entry *smbios_entry(u64 address, u32 size) { const struct smbios_entry *entry = (struct smbios_entry *)(uintptr_t)address; if (!address | !size) return NULL; if (memcmp(entry->anchor, "_SM_", 4)) return NULL; if (verify_checksum(entry)) return NULL; return entry; } static const struct smbios_header *next_header(const struct smbios_header *curr) { u8 *pos = ((u8 *)curr) + curr->length; /* search for _double_ NULL bytes */ while (!((*pos == 0) && (*(pos + 1) == 0))) pos++; /* step behind the double NULL bytes */ pos += 2; return (struct smbios_header *)pos; } const struct smbios_header *smbios_header(const struct smbios_entry *entry, int type) { const unsigned int num_header = entry->struct_count; const struct smbios_header *header = (struct smbios_header *)entry->struct_table_address; for (unsigned int i = 0; i < num_header; i++) { if (header->type == type) return header; header = next_header(header); } return NULL; } static const char *string_from_smbios_table(const struct smbios_header *header, int idx) { unsigned int i = 1; u8 *pos; if (!header) return NULL; pos = ((u8 *)header) + header->length; while (i < idx) { if (*pos == 0x0) i++; pos++; } return (const char *)pos; } const char *smbios_string(const struct smbios_header *header, int index) { if (!header) return NULL; return string_from_smbios_table(header, index); } int smbios_update_version_full(void *smbios_tab, const char *version) { const struct smbios_header *hdr; struct smbios_type0 *bios; uint old_len, len; char *ptr; log_info("Updating SMBIOS table at %p\n", smbios_tab); hdr = smbios_header(smbios_tab, SMBIOS_BIOS_INFORMATION); if (!hdr) return log_msg_ret("tab", -ENOENT); bios = (struct smbios_type0 *)hdr; ptr = (char *)smbios_string(hdr, bios->bios_ver); if (!ptr) return log_msg_ret("str", -ENOMEDIUM); /* * This string is supposed to have at least enough bytes and is * padded with spaces. Update it, taking care not to move the * \0 terminator, so that other strings in the string table * are not disturbed. See smbios_add_string() */ old_len = strnlen(ptr, SMBIOS_STR_MAX); len = strnlen(version, SMBIOS_STR_MAX); if (len > old_len) return log_ret(-ENOSPC); log_debug("Replacing SMBIOS type 0 version string '%s'\n", ptr); memcpy(ptr, version, len); #ifdef LOG_DEBUG print_buffer((ulong)ptr, ptr, 1, old_len + 1, 0); #endif return 0; } |