src/boot/efi/util.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /*
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU Lesser General Public License as published by
   6  * the Free Software Foundation; either version 2.1 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * Copyright (C) 2012-2013 Kay Sievers <kay@vrfy.org>
  15  * Copyright (C) 2012 Harald Hoyer <harald@redhat.com>
  16  */
  17
  18 #include <efi.h>
  19 #include <efilib.h>
  20
  21 #include "util.h"
  22
  23 /*
  24  * Allocated random UUID, intended to be shared across tools that implement
  25  * the (ESP)\loader\entries\<vendor>-<revision>.conf convention and the
  26  * associated EFI variables.
  27  */
  28 static const EFI_GUID loader_guid = { 0x4a67b082, 0x0a4c, 0x41cf, {0xb6, 0xc7, 0x44, 0x0b, 0x29, 0xbb, 0x8c, 0x4f} };
  29
  30 #ifdef __x86_64__
  31 UINT64 ticks_read(VOID) {
  32         UINT64 a, d;
  33         __asm__ volatile ("rdtsc" : "=a" (a), "=d" (d));
  34         return (d << 32) | a;
  35 }
  36 #elif defined(__i386__)
  37 UINT64 ticks_read(VOID) {
  38         UINT64 val;
  39         __asm__ volatile ("rdtsc" : "=A" (val));
  40         return val;
  41 }
  42 #else
  43 UINT64 ticks_read(VOID) {
  44         UINT64 val = 1;
  45         return val;
  46 }
  47 #endif
  48
  49 /* count TSC ticks during a millisecond delay */
  50 UINT64 ticks_freq(VOID) {
  51         UINT64 ticks_start, ticks_end;
  52
  53         ticks_start = ticks_read();
  54         uefi_call_wrapper(BS->Stall, 1, 1000);
  55         ticks_end = ticks_read();
  56
  57         return (ticks_end - ticks_start) * 1000;
  58 }
  59
  60 UINT64 time_usec(VOID) {
  61         UINT64 ticks;
  62         static UINT64 freq;
  63
  64         ticks = ticks_read();
  65         if (ticks == 0)
  66                 return 0;
  67
  68         if (freq == 0) {
  69                 freq = ticks_freq();
  70                 if (freq == 0)
  71                         return 0;
  72         }
  73
  74         return 1000 * 1000 * ticks / freq;
  75 }
  76
  77 EFI_STATUS parse_boolean(CHAR8 *v, BOOLEAN *b) {
  78         if (strcmpa(v, (CHAR8 *)"1") == 0 ||
  79             strcmpa(v, (CHAR8 *)"yes") == 0 ||
  80             strcmpa(v, (CHAR8 *)"y") == 0 ||
  81             strcmpa(v, (CHAR8 *)"true") == 0) {
  82                 *b = TRUE;
  83                 return EFI_SUCCESS;
  84         }
  85
  86         if (strcmpa(v, (CHAR8 *)"0") == 0 ||
  87             strcmpa(v, (CHAR8 *)"no") == 0 ||
  88             strcmpa(v, (CHAR8 *)"n") == 0 ||
  89             strcmpa(v, (CHAR8 *)"false") == 0) {
  90                 *b = FALSE;
  91                 return EFI_SUCCESS;
  92         }
  93
  94         return EFI_INVALID_PARAMETER;
  95 }
  96
  97 EFI_STATUS efivar_set_raw(const EFI_GUID *vendor, CHAR16 *name, CHAR8 *buf, UINTN size, BOOLEAN persistent) {
  98         UINT32 flags;
  99
 100         flags = EFI_VARIABLE_BOOTSERVICE_ACCESS|EFI_VARIABLE_RUNTIME_ACCESS;
 101         if (persistent)
 102                 flags |= EFI_VARIABLE_NON_VOLATILE;
 103
 104         return uefi_call_wrapper(RT->SetVariable, 5, name, (EFI_GUID *)vendor, flags, size, buf);
 105 }
 106
 107 EFI_STATUS efivar_set(CHAR16 *name, CHAR16 *value, BOOLEAN persistent) {
 108         return efivar_set_raw(&loader_guid, name, (CHAR8 *)value, value ? (StrLen(value)+1) * sizeof(CHAR16) : 0, persistent);
 109 }
 110
 111 EFI_STATUS efivar_set_int(CHAR16 *name, UINTN i, BOOLEAN persistent) {
 112         CHAR16 str[32];
 113
 114         SPrint(str, 32, L"%d", i);
 115         return efivar_set(name, str, persistent);
 116 }
 117
 118 EFI_STATUS efivar_get(CHAR16 *name, CHAR16 **value) {
 119         CHAR8 *buf;
 120         CHAR16 *val;
 121         UINTN size;
 122         EFI_STATUS err;
 123
 124         err = efivar_get_raw(&loader_guid, name, &buf, &size);
 125         if (EFI_ERROR(err))
 126                 return err;
 127
 128         val = StrDuplicate((CHAR16 *)buf);
 129         if (!val) {
 130                 FreePool(buf);
 131                 return EFI_OUT_OF_RESOURCES;
 132         }
 133
 134         *value = val;
 135         return EFI_SUCCESS;
 136 }
 137
 138 EFI_STATUS efivar_get_int(CHAR16 *name, UINTN *i) {
 139         CHAR16 *val;
 140         EFI_STATUS err;
 141
 142         err = efivar_get(name, &val);
 143         if (!EFI_ERROR(err)) {
 144                 *i = Atoi(val);
 145                 FreePool(val);
 146         }
 147         return err;
 148 }
 149
 150 EFI_STATUS efivar_get_raw(const EFI_GUID *vendor, CHAR16 *name, CHAR8 **buffer, UINTN *size) {
 151         CHAR8 *buf;
 152         UINTN l;
 153         EFI_STATUS err;
 154
 155         l = sizeof(CHAR16 *) * EFI_MAXIMUM_VARIABLE_SIZE;
 156         buf = AllocatePool(l);
 157         if (!buf)
 158                 return EFI_OUT_OF_RESOURCES;
 159
 160         err = uefi_call_wrapper(RT->GetVariable, 5, name, (EFI_GUID *)vendor, NULL, &l, buf);
 161         if (!EFI_ERROR(err)) {
 162                 *buffer = buf;
 163                 if (size)
 164                         *size = l;
 165         } else
 166                 FreePool(buf);
 167         return err;
 168
 169 }
 170
 171 VOID efivar_set_time_usec(CHAR16 *name, UINT64 usec) {
 172         CHAR16 str[32];
 173
 174         if (usec == 0)
 175                 usec = time_usec();
 176         if (usec == 0)
 177                 return;
 178
 179         SPrint(str, 32, L"%ld", usec);
 180         efivar_set(name, str, FALSE);
 181 }
 182
 183 static INTN utf8_to_16(CHAR8 *stra, CHAR16 *c) {
 184         CHAR16 unichar;
 185         UINTN len;
 186         UINTN i;
 187
 188         if (stra[0] < 0x80)
 189                 len = 1;
 190         else if ((stra[0] & 0xe0) == 0xc0)
 191                 len = 2;
 192         else if ((stra[0] & 0xf0) == 0xe0)
 193                 len = 3;
 194         else if ((stra[0] & 0xf8) == 0xf0)
 195                 len = 4;
 196         else if ((stra[0] & 0xfc) == 0xf8)
 197                 len = 5;
 198         else if ((stra[0] & 0xfe) == 0xfc)
 199                 len = 6;
 200         else
 201                 return -1;
 202
 203         switch (len) {
 204         case 1:
 205                 unichar = stra[0];
 206                 break;
 207         case 2:
 208                 unichar = stra[0] & 0x1f;
 209                 break;
 210         case 3:
 211                 unichar = stra[0] & 0x0f;
 212                 break;
 213         case 4:
 214                 unichar = stra[0] & 0x07;
 215                 break;
 216         case 5:
 217                 unichar = stra[0] & 0x03;
 218                 break;
 219         case 6:
 220                 unichar = stra[0] & 0x01;
 221                 break;
 222         }
 223
 224         for (i = 1; i < len; i++) {
 225                 if ((stra[i] & 0xc0) != 0x80)
 226                         return -1;
 227                 unichar <<= 6;
 228                 unichar |= stra[i] & 0x3f;
 229         }
 230
 231         *c = unichar;
 232         return len;
 233 }
 234
 235 CHAR16 *stra_to_str(CHAR8 *stra) {
 236         UINTN strlen;
 237         UINTN len;
 238         UINTN i;
 239         CHAR16 *str;
 240
 241         len = strlena(stra);
 242         str = AllocatePool((len + 1) * sizeof(CHAR16));
 243
 244         strlen = 0;
 245         i = 0;
 246         while (i < len) {
 247                 INTN utf8len;
 248
 249                 utf8len = utf8_to_16(stra + i, str + strlen);
 250                 if (utf8len <= 0) {
 251                         /* invalid utf8 sequence, skip the garbage */
 252                         i++;
 253                         continue;
 254                 }
 255
 256                 strlen++;
 257                 i += utf8len;
 258         }
 259         str[strlen] = '\0';
 260         return str;
 261 }
 262
 263 CHAR16 *stra_to_path(CHAR8 *stra) {
 264         CHAR16 *str;
 265         UINTN strlen;
 266         UINTN len;
 267         UINTN i;
 268
 269         len = strlena(stra);
 270         str = AllocatePool((len + 2) * sizeof(CHAR16));
 271
 272         str[0] = '\\';
 273         strlen = 1;
 274         i = 0;
 275         while (i < len) {
 276                 INTN utf8len;
 277
 278                 utf8len = utf8_to_16(stra + i, str + strlen);
 279                 if (utf8len <= 0) {
 280                         /* invalid utf8 sequence, skip the garbage */
 281                         i++;
 282                         continue;
 283                 }
 284
 285                 if (str[strlen] == '/')
 286                         str[strlen] = '\\';
 287                 if (str[strlen] == '\\' && str[strlen-1] == '\\') {
 288                         /* skip double slashes */
 289                         i += utf8len;
 290                         continue;
 291                 }
 292
 293                 strlen++;
 294                 i += utf8len;
 295         }
 296         str[strlen] = '\0';
 297         return str;
 298 }
 299
 300 CHAR8 *strchra(CHAR8 *s, CHAR8 c) {
 301         do {
 302                 if (*s == c)
 303                         return s;
 304         } while (*s++);
 305         return NULL;
 306 }
 307
 308 INTN file_read(EFI_FILE_HANDLE dir, CHAR16 *name, UINTN off, UINTN size, CHAR8 **content) {
 309         EFI_FILE_HANDLE handle;
 310         CHAR8 *buf;
 311         UINTN buflen;
 312         EFI_STATUS err;
 313         UINTN len;
 314
 315         err = uefi_call_wrapper(dir->Open, 5, dir, &handle, name, EFI_FILE_MODE_READ, 0ULL);
 316         if (EFI_ERROR(err))
 317                 return err;
 318
 319         if (size == 0) {
 320                 EFI_FILE_INFO *info;
 321
 322                 info = LibFileInfo(handle);
 323                 buflen = info->FileSize+1;
 324                 FreePool(info);
 325         } else
 326                 buflen = size;
 327
 328         if (off > 0) {
 329                 err = uefi_call_wrapper(handle->SetPosition, 2, handle, off);
 330                 if (EFI_ERROR(err))
 331                         return err;
 332         }
 333
 334         buf = AllocatePool(buflen);
 335         err = uefi_call_wrapper(handle->Read, 3, handle, &buflen, buf);
 336         if (!EFI_ERROR(err)) {
 337                 buf[buflen] = '\0';
 338                 *content = buf;
 339                 len = buflen;
 340         } else {
 341                 len = err;
 342                 FreePool(buf);
 343         }
 344
 345         uefi_call_wrapper(handle->Close, 1, handle);
 346         return len;
 347 }