libinstaller/syslxint.h

   1 /* ----------------------------------------------------------------------- *
   2  *
   3  *   Copyright 2007-2008 H. Peter Anvin - All Rights Reserved
   4  *   Copyright 2009-2011 Intel Corporation; author: H. Peter Anvin
   5  *   Copyright 2011 Paulo Alcantara <pcacjr@gmail.com>
   6  *
   7  *   This program is free software; you can redistribute it and/or modify
   8  *   it under the terms of the GNU General Public License as published by
   9  *   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
  10  *   Boston MA 02111-1307, USA; either version 2 of the License, or
  11  *   (at your option) any later version; incorporated herein by reference.
  12  *
  13  * ----------------------------------------------------------------------- */
  14
  15 #ifndef SYSLXINT_H
  16 #define SYSLXINT_H
  17
  18 #include "syslinux.h"
  19
  20 #if defined(__386__) || defined(__i386__) || defined(__x86_64__)
  21 # define X86_MEM 1              /* Littleendian and unaligned safe */
  22 #else
  23 # define X86_MEM 0
  24 #endif
  25
  26 #ifdef __GNUC__
  27 # ifdef __MINGW32__
  28    /* gcc 4.7 miscompiles packed structures in MS-bitfield mode */
  29 #  define PACKED __attribute__((packed,gcc_struct))
  30 # else
  31 #  define PACKED __attribute__((packed))
  32 # endif
  33 #else
  34 # error "Need to define PACKED for this compiler"
  35 #endif
  36
  37 /*
  38  * Access functions for littleendian numbers, possibly misaligned.
  39  */
  40 static inline uint8_t get_8(const uint8_t * p)
  41 {
  42     return *p;
  43 }
  44
  45 static inline uint16_t get_16(const uint16_t * p)
  46 {
  47 #if X86_MEM
  48     /* Littleendian and unaligned-capable */
  49     return *p;
  50 #else
  51     const uint8_t *pp = (const uint8_t *)p;
  52     return pp[0] + ((uint16_t)pp[1] << 8);
  53 #endif
  54 }
  55
  56 static inline uint32_t get_32(const uint32_t * p)
  57 {
  58 #if X86_MEM
  59     /* Littleendian and unaligned-capable */
  60     return *p;
  61 #else
  62     const uint16_t *pp = (const uint16_t *)p;
  63     return get_16(pp[0]) + (uint32_t)get_16(pp[1]);
  64 #endif
  65 }
  66
  67 static inline uint64_t get_64(const uint64_t * p)
  68 {
  69 #if X86_MEM
  70     /* Littleendian and unaligned-capable */
  71     return *p;
  72 #else
  73     const uint32_t *pp = (const uint32_t *)p;
  74     return get_32(pp[0]) + (uint64_t)get_32(pp[1]);
  75 #endif
  76 }
  77
  78 static inline void set_8(uint8_t *p, uint8_t v)
  79 {
  80     *p = v;
  81 }
  82
  83 static inline void set_16(uint16_t *p, uint16_t v)
  84 {
  85 #if X86_MEM
  86     /* Littleendian and unaligned-capable */
  87     *p = v;
  88 #else
  89     uint8_t *pp = (uint8_t *) p;
  90     pp[0] = (v & 0xff);
  91     pp[1] = ((v >> 8) & 0xff);
  92 #endif
  93 }
  94
  95 static inline void set_32(uint32_t *p, uint32_t v)
  96 {
  97 #if X86_MEM
  98     /* Littleendian and unaligned-capable */
  99     *p = v;
 100 #else
 101     uint8_t *pp = (uint8_t *) p;
 102     pp[0] = (v & 0xff);
 103     pp[1] = ((v >> 8) & 0xff);
 104     pp[2] = ((v >> 16) & 0xff);
 105     pp[3] = ((v >> 24) & 0xff);
 106 #endif
 107 }
 108
 109 static inline void set_64(uint64_t *p, uint64_t v)
 110 {
 111 #if X86_MEM
 112     /* Littleendian and unaligned-capable */
 113     *p = v;
 114 #else
 115     uint32_t *pp = (uint32_t *) p;
 116     set_32(pp[0], v);
 117     set_32(pp[1], v >> 32);
 118 #endif
 119 }
 120
 121 /*
 122  * Special handling for the MS-DOS derivative: syslinux_ldlinux
 123  * is a "far" object...
 124  */
 125 #ifdef __MSDOS__
 126
 127 static inline __attribute__ ((const))
 128 uint16_t ds(void)
 129 {
 130     uint16_t v;
 131     asm("movw %%ds,%0":"=rm"(v));
 132     return v;
 133 }
 134
 135 static inline void *set_fs(const void *p)
 136 {
 137     uint16_t seg;
 138
 139     seg = ds() + ((size_t) p >> 4);
 140     asm volatile ("movw %0,%%fs"::"rm" (seg));
 141     return (void *)((size_t) p & 0xf);
 142 }
 143
 144 uint8_t get_8_sl(const uint8_t * p);
 145 uint16_t get_16_sl(const uint16_t * p);
 146 uint32_t get_32_sl(const uint32_t * p);
 147 uint64_t get_64_sl(const uint64_t * p);
 148 void set_8_sl(uint8_t * p, uint8_t v);
 149 void set_16_sl(uint16_t * p, uint16_t v);
 150 void set_32_sl(uint32_t * p, uint32_t v);
 151 void set_64_sl(uint64_t * p, uint64_t v);
 152 void memcpy_to_sl(void *dst, const void *src, size_t len);
 153 void memcpy_from_sl(void *dst, const void *src, size_t len);
 154
 155 #else
 156
 157 /* Sane system ... */
 158 #define get_8_sl(x)             get_8(x)
 159 #define get_16_sl(x)            get_16(x)
 160 #define get_32_sl(x)            get_32(x)
 161 #define get_64_sl(x)            get_64(x)
 162 #define set_8_sl(x,y)           set_8(x,y)
 163 #define set_16_sl(x,y)          set_16(x,y)
 164 #define set_32_sl(x,y)          set_32(x,y)
 165 #define set_64_sl(x,y)          set_64(x,y)
 166 #define memcpy_to_sl(d,s,l)     memcpy(d,s,l)
 167 #define memcpy_from_sl(d,s,l)   memcpy(d,s,l)
 168
 169 #endif
 170
 171 #define LDLINUX_MAGIC   0x3eb202fe
 172 #define BS_MAGIC_VER    (0x1b << 9)
 173
 174 /* Patch area for disk-based installers */
 175 struct patch_area {
 176     uint32_t magic;             /* LDLINUX_MAGIC */
 177     uint32_t instance;          /* Per-version value */
 178     uint16_t data_sectors;
 179     uint16_t adv_sectors;
 180     uint32_t dwords;
 181     uint32_t checksum;
 182     uint16_t maxtransfer;
 183     uint16_t epaoffset;         /* Pointer to the extended patch area */
 184 };
 185
 186 struct ext_patch_area {
 187     uint16_t advptroffset;      /* ADV pointers */
 188     uint16_t diroffset;         /* Current directory field */
 189     uint16_t dirlen;            /* Length of current directory field */
 190     uint16_t subvoloffset;      /* Subvolume field */
 191     uint16_t subvollen;         /* Length of subvolume field */
 192     uint16_t secptroffset;      /* Sector extent pointers */
 193     uint16_t secptrcnt;         /* Number of sector extent pointers */
 194
 195     uint16_t sect1ptr0;         /* Boot sector offset of sector 1 ptr LSW */
 196     uint16_t sect1ptr1;         /* Boot sector offset of sector 1 ptr MSW */
 197     uint16_t raidpatch;         /* Boot sector RAID mode patch pointer */
 198 };
 199
 200 /* Sector extent */
 201 struct syslinux_extent {
 202     uint64_t lba;
 203     uint16_t len;
 204 } PACKED;
 205
 206 /* FAT bootsector format, also used by other disk-based derivatives */
 207 struct fat_boot_sector {
 208     uint8_t bsJump[3];
 209     char bsOemName[8];
 210     uint16_t bsBytesPerSec;
 211     uint8_t bsSecPerClust;
 212     uint16_t bsResSectors;
 213     uint8_t bsFATs;
 214     uint16_t bsRootDirEnts;
 215     uint16_t bsSectors;
 216     uint8_t bsMedia;
 217     uint16_t bsFATsecs;
 218     uint16_t bsSecPerTrack;
 219     uint16_t bsHeads;
 220     uint32_t bsHiddenSecs;
 221     uint32_t bsHugeSectors;
 222
 223     union {
 224         struct {
 225             uint8_t DriveNumber;
 226             uint8_t Reserved1;
 227             uint8_t BootSignature;
 228             uint32_t VolumeID;
 229             char VolumeLabel[11];
 230             char FileSysType[8];
 231             uint8_t Code[442];
 232         } PACKED bs16;
 233         struct {
 234             uint32_t FATSz32;
 235             uint16_t ExtFlags;
 236             uint16_t FSVer;
 237             uint32_t RootClus;
 238             uint16_t FSInfo;
 239             uint16_t BkBootSec;
 240             uint8_t Reserved0[12];
 241             uint8_t DriveNumber;
 242             uint8_t Reserved1;
 243             uint8_t BootSignature;
 244             uint32_t VolumeID;
 245             char VolumeLabel[11];
 246             char FileSysType[8];
 247             uint8_t Code[414];
 248         } PACKED bs32;
 249     } PACKED;
 250
 251     uint32_t bsMagic;
 252     uint16_t bsForwardPtr;
 253     uint16_t bsSignature;
 254 } PACKED;
 255
 256 /* NTFS bootsector format */
 257 struct ntfs_boot_sector {
 258     uint8_t bsJump[3];
 259     char bsOemName[8];
 260     uint16_t bsBytesPerSec;
 261     uint8_t bsSecPerClust;
 262     uint16_t bsResSectors;
 263     uint8_t bsZeroed_0[3];
 264     uint16_t bsZeroed_1;
 265     uint8_t bsMedia;
 266     uint16_t bsZeroed_2;
 267     uint16_t bsUnused_0;
 268     uint16_t bsUnused_1;
 269     uint32_t bsUnused_2;
 270     uint32_t bsZeroed_3;
 271     uint32_t bsUnused_3;
 272     uint64_t bsTotalSectors;
 273     uint64_t bsMFTLogicalClustNr;
 274     uint64_t bsMFTMirrLogicalClustNr;
 275     uint8_t bsClustPerMFTrecord;
 276     uint8_t bsUnused_4[3];
 277     uint8_t bsClustPerIdxBuf;
 278     uint8_t bsUnused_5[3];
 279     uint64_t bsVolSerialNr;
 280     uint32_t bsUnused_6;
 281
 282     uint8_t Code[420];
 283
 284     uint32_t bsMagic;
 285     uint16_t bsForwardPtr;
 286     uint16_t bsSignature;
 287 } PACKED;
 288
 289 #define FAT_bsHead      bsJump
 290 #define FAT_bsHeadLen   offsetof(struct fat_boot_sector, bsBytesPerSec)
 291 #define FAT_bsCode          bs32.Code   /* The common safe choice */
 292 #define FAT_bsCodeLen   (offsetof(struct fat_boot_sector, bsSignature) - \
 293                      offsetof(struct fat_boot_sector, FAT_bsCode))
 294
 295 #define NTFS_bsHead     bsJump
 296 #define NTFS_bsHeadLen  offsetof(struct ntfs_boot_sector, bsOemName)
 297 #define NTFS_bsCode     Code
 298 #define NTFS_bsCodeLen  (offsetof(struct ntfs_boot_sector, bsSignature) - \
 299                             offsetof(struct ntfs_boot_sector, NTFS_bsCode))
 300
 301 /* Check if there are specific zero fields in an NTFS boot sector */
 302 static inline int ntfs_check_zero_fields(const struct ntfs_boot_sector *sb)
 303 {
 304     return !sb->bsResSectors && (!sb->bsZeroed_0[0] && !sb->bsZeroed_0[1] &&
 305             !sb->bsZeroed_0[2]) && !sb->bsZeroed_1 && !sb->bsZeroed_2 &&
 306             !sb->bsZeroed_3;
 307 }
 308
 309 static inline int ntfs_check_sb_fields(const struct ntfs_boot_sector *sb)
 310 {
 311     return ntfs_check_zero_fields(sb) &&
 312             (!memcmp(sb->bsOemName, "NTFS    ", 8) ||
 313              !memcmp(sb->bsOemName, "MSWIN4.0", 8) ||
 314              !memcmp(sb->bsOemName, "MSWIN4.1", 8));
 315 }
 316
 317 static inline int fat_check_sb_fields(const struct fat_boot_sector *sb)
 318 {
 319     return sb->bsResSectors && sb->bsFATs &&
 320             (!memcmp(sb->bs16.FileSysType, "FAT12   ", 8) ||
 321              !memcmp(sb->bs16.FileSysType, "FAT16   ", 8) ||
 322              !memcmp(sb->bs16.FileSysType, "FAT     ", 8) ||
 323              !memcmp(sb->bs32.FileSysType, "FAT32   ", 8));
 324 }
 325
 326 #endif /* SYSLXINT_H */