libinstaller/syslxint.h

   1 /* ----------------------------------------------------------------------- *
   2  *
   3  *   Copyright 2007-2008 H. Peter Anvin - All Rights Reserved
   4  *
   5  *   This program is free software; you can redistribute it and/or modify
   6  *   it under the terms of the GNU General Public License as published by
   7  *   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
   8  *   Boston MA 02111-1307, USA; either version 2 of the License, or
   9  *   (at your option) any later version; incorporated herein by reference.
  10  *
  11  * ----------------------------------------------------------------------- */
  12
  13 #ifndef SYSLXINT_H
  14 #define SYSLXINT_H
  15
  16 #include "syslinux.h"
  17
  18 #if defined(__386__) || defined(__i386__) || defined(__x86_64__)
  19 # define X86_MEM 1              /* Littleendian and unaligned safe */
  20 #else
  21 # define X86_MEM 0
  22 #endif
  23
  24 /*
  25  * Access functions for littleendian numbers, possibly misaligned.
  26  */
  27 static inline uint8_t get_8(const uint8_t * p)
  28 {
  29     return *p;
  30 }
  31
  32 static inline uint16_t get_16(const uint16_t * p)
  33 {
  34 #if X86_MEM
  35     /* Littleendian and unaligned-capable */
  36     return *p;
  37 #else
  38     const uint8_t *pp = (const uint8_t *)p;
  39     return pp[0] + ((uint16_t)pp[1] << 8);
  40 #endif
  41 }
  42
  43 static inline uint32_t get_32(const uint32_t * p)
  44 {
  45 #if X86_MEM
  46     /* Littleendian and unaligned-capable */
  47     return *p;
  48 #else
  49     const uint16_t *pp = (const uint16_t *)p;
  50     return get_16(pp[0]) + (uint32_t)get_16(pp[1]);
  51 #endif
  52 }
  53
  54 static inline uint64_t get_64(const uint64_t * p)
  55 {
  56 #if X86_MEM
  57     /* Littleendian and unaligned-capable */
  58     return *p;
  59 #else
  60     const uint32_t *pp = (const uint32_t *)p;
  61     return get_32(pp[0]) + (uint64_t)get_32(pp[1]);
  62 #endif
  63 }
  64
  65 static inline void set_8(uint8_t *p, uint8_t v)
  66 {
  67     *p = v;
  68 }
  69
  70 static inline void set_16(uint16_t *p, uint16_t v)
  71 {
  72 #if X86_MEM
  73     /* Littleendian and unaligned-capable */
  74     *p = v;
  75 #else
  76     uint8_t *pp = (uint8_t *) p;
  77     pp[0] = (v & 0xff);
  78     pp[1] = ((v >> 8) & 0xff);
  79 #endif
  80 }
  81
  82 static inline void set_32(uint32_t *p, uint32_t v)
  83 {
  84 #if X86_MEM
  85     /* Littleendian and unaligned-capable */
  86     *p = v;
  87 #else
  88     uint8_t *pp = (uint8_t *) p;
  89     pp[0] = (v & 0xff);
  90     pp[1] = ((v >> 8) & 0xff);
  91     pp[2] = ((v >> 16) & 0xff);
  92     pp[3] = ((v >> 24) & 0xff);
  93 #endif
  94 }
  95
  96 static inline void set_64(uint64_t *p, uint64_t v)
  97 {
  98 #if X86_MEM
  99     /* Littleendian and unaligned-capable */
 100     *p = v;
 101 #else
 102     uint32_t *pp = (uint32_t *) p;
 103     set_32(pp[0], v);
 104     set_32(pp[1], v >> 32);
 105 #endif
 106 }
 107
 108 /*
 109  * Special handling for the MS-DOS derivative: syslinux_ldlinux
 110  * is a "far" object...
 111  */
 112 #ifdef __MSDOS__
 113
 114 static inline __attribute__ ((const))
 115 uint16_t ds(void)
 116 {
 117     uint16_t v;
 118     asm("movw %%ds,%0":"=rm"(v));
 119     return v;
 120 }
 121
 122 static inline void *set_fs(const void *p)
 123 {
 124     uint16_t seg;
 125
 126     seg = ds() + ((size_t) p >> 4);
 127     asm volatile ("movw %0,%%fs"::"rm" (seg));
 128     return (void *)((size_t) p & 0xf);
 129 }
 130
 131 uint8_t get_8_sl(const uint8_t * p);
 132 uint16_t get_16_sl(const uint16_t * p);
 133 uint32_t get_32_sl(const uint32_t * p);
 134 uint64_t get_64_sl(const uint64_t * p);
 135 void set_8_sl(uint8_t * p, uint8_t v);
 136 void set_16_sl(uint16_t * p, uint16_t v);
 137 void set_32_sl(uint32_t * p, uint32_t v);
 138 void set_64_sl(uint64_t * p, uint64_t v);
 139 void memcpy_to_sl(void *dst, const void *src, size_t len);
 140 void memcpy_from_sl(void *dst, const void *src, size_t len);
 141
 142 #else
 143
 144 /* Sane system ... */
 145 #define get_8_sl(x)             get_8(x)
 146 #define get_16_sl(x)            get_16(x)
 147 #define get_32_sl(x)            get_32(x)
 148 #define get_64_sl(x)            get_64(x)
 149 #define set_8_sl(x,y)           set_8(x,y)
 150 #define set_16_sl(x,y)          set_16(x,y)
 151 #define set_32_sl(x,y)          set_32(x,y)
 152 #define set_64_sl(x,y)          set_64(x,y)
 153 #define memcpy_to_sl(d,s,l)     memcpy(d,s,l)
 154 #define memcpy_from_sl(d,s,l)   memcpy(d,s,l)
 155
 156 #endif
 157
 158 #define LDLINUX_MAGIC   0x3eb202fe
 159
 160 /* Patch area for disk-based installers */
 161 struct patch_area {
 162     uint32_t magic;             /* LDLINUX_MAGIC */
 163     uint32_t instance;          /* Per-version value */
 164     uint16_t data_sectors;
 165     uint16_t adv_sectors;
 166     uint32_t dwords;
 167     uint32_t checksum;
 168     uint16_t maxtransfer;
 169     uint16_t epaoffset;         /* Pointer to the extended patch area */
 170 };
 171
 172 struct ext_patch_area {
 173     uint16_t advptroffset;      /* ADV pointers */
 174     uint16_t diroffset;         /* Current directory field */
 175     uint16_t dirlen;            /* Length of current directory field */
 176     uint16_t subvoloffset;      /* Subvolume field */
 177     uint16_t subvollen;         /* Length of subvolume field */
 178     uint16_t secptroffset;      /* Sector extent pointers */
 179     uint16_t secptrcnt;         /* Number of sector extent pointers */
 180
 181     uint16_t sect1ptr0;         /* Boot sector offset of sector 1 ptr LSW */
 182     uint16_t sect1ptr1;         /* Boot sector offset of sector 1 ptr MSW */
 183     uint16_t raidpatch;         /* Boot sector RAID mode patch pointer */
 184 };
 185
 186 /* Sector extent */
 187 struct syslinux_extent {
 188     uint64_t lba;
 189     uint16_t len;
 190 } __attribute__((packed));
 191
 192 /* FAT bootsector format, also used by other disk-based derivatives */
 193 struct boot_sector {
 194     uint8_t bsJump[3];
 195     char bsOemName[8];
 196     uint16_t bsBytesPerSec;
 197     uint8_t bsSecPerClust;
 198     uint16_t bsResSectors;
 199     uint8_t bsFATs;
 200     uint16_t bsRootDirEnts;
 201     uint16_t bsSectors;
 202     uint8_t bsMedia;
 203     uint16_t bsFATsecs;
 204     uint16_t bsSecPerTrack;
 205     uint16_t bsHeads;
 206     uint32_t bsHiddenSecs;
 207     uint32_t bsHugeSectors;
 208
 209     union {
 210         struct {
 211             uint8_t DriveNumber;
 212             uint8_t Reserved1;
 213             uint8_t BootSignature;
 214             uint32_t VolumeID;
 215             char VolumeLabel[11];
 216             char FileSysType[8];
 217             uint8_t Code[448];
 218         } __attribute__ ((packed)) bs16;
 219         struct {
 220             uint32_t FATSz32;
 221             uint16_t ExtFlags;
 222             uint16_t FSVer;
 223             uint32_t RootClus;
 224             uint16_t FSInfo;
 225             uint16_t BkBootSec;
 226             uint8_t Reserved0[12];
 227             uint8_t DriveNumber;
 228             uint8_t Reserved1;
 229             uint8_t BootSignature;
 230             uint32_t VolumeID;
 231             char VolumeLabel[11];
 232             char FileSysType[8];
 233             uint8_t Code[420];
 234         } __attribute__ ((packed)) bs32;
 235     } __attribute__ ((packed));
 236
 237     uint16_t bsSignature;
 238 } __attribute__ ((packed));
 239
 240 #define bsHead      bsJump
 241 #define bsHeadLen   offsetof(struct boot_sector, bsBytesPerSec)
 242 #define bsCode      bs32.Code   /* The common safe choice */
 243 #define bsCodeLen   (offsetof(struct boot_sector, bsSignature) - \
 244                      offsetof(struct boot_sector, bsCode))
 245
 246 #endif /* SYSLXINT_H */