boot/freeldr/freeldr/include/arch/pc/x86common.h

   1
   2 #ifndef HEX
   3 #define HEX(y) 0x##y
   4 #endif
   5
   6 /* Memory layout */
   7 #ifdef _M_AMD64
   8 #define PML4_ADDRESS        HEX(1000) /* One page PML4 page table */
   9 #define PDP_ADDRESS         HEX(2000) /* One page PDP page table */
  10 #define PD_ADDRESS          HEX(3000) /* One page PD page table */
  11 #endif
  12 #define BIOSCALLBUFFER      HEX(4000) /* Buffer to store temporary data for any Int386() call */
  13 #define STACK16ADDR         HEX(6F00) /* The 16-bit stack top will be at 0000:6F00 */
  14 #define BSS_START           HEX(6F00)
  15 #define STACKLOW            HEX(7000)
  16 #define STACKADDR           HEX(F000) /* The 32/64-bit stack top will be at 0000:F000, or 0xF000 */
  17 #define FREELDR_BASE        HEX(F800)
  18 #define FREELDR_PE_BASE    HEX(10000)
  19 #define MEMORY_MARGIN      HEX(88000) /* We need this much memory */
  20
  21 #define BIOSCALLBUFSEGMENT (BIOSCALLBUFFER/16) /* Buffer to store temporary data for any Int386() call */
  22 #define BIOSCALLBUFOFFSET   HEX(0000) /* Buffer to store temporary data for any Int386() call */
  23 #define BIOSCALLBUFSIZE     PAGE_SIZE /* max is sizeof(VESA_SVGA_INFO) = 512 */
  24 #define MAX_FREELDR_PE_SIZE (MEMORY_MARGIN - FREELDR_PE_BASE - PAGE_SIZE)
  25
  26 /* MAX_DISKREADBUFFER_SIZE is later passed to INT 13h, AH=42h.
  27    According to https://en.wikipedia.org/wiki/INT_13H#INT_13h_AH.3D42h:_Extended_Read_Sectors_From_Drive
  28    some BIOSes can only read a maximum of 127 sectors. (0xFE00 / 512 = 127)
  29    Confirmed when booting from USB on Dell Latitude D531 and Lenovo ThinkPad X61. */
  30 #define MAX_DISKREADBUFFER_SIZE HEX(FE00)
  31
  32 /* These addresses specify the realmode "BSS section" layout */
  33 #define BSS_RealModeEntry        (BSS_START +  0)
  34 #define BSS_CallbackReturn       (BSS_START +  4)
  35 #define BSS_RegisterSet          (BSS_START +  8) /* size = 40 */
  36 #define BSS_IntVector            (BSS_START + 52)
  37 #define BSS_PxeEntryPoint        (BSS_START + 56)
  38 #define BSS_PxeBufferSegment     (BSS_START + 60)
  39 #define BSS_PxeBufferOffset      (BSS_START + 64)
  40 #define BSS_PxeFunction          (BSS_START + 68)
  41 #define BSS_PxeResult            (BSS_START + 72)
  42 #define BSS_PnpBiosEntryPoint    (BSS_START + 76)
  43 #define BSS_PnpBiosDataSegment   (BSS_START + 80)
  44 #define BSS_PnpBiosBufferSegment (BSS_START + 84)
  45 #define BSS_PnpBiosBufferOffset  (BSS_START + 88)
  46 #define BSS_PnpNodeSize          (BSS_START + 92)
  47 #define BSS_PnpNodeCount         (BSS_START + 96)
  48 #define BSS_PnpNodeNumber        (BSS_START + 100)
  49 #define BSS_PnpResult            (BSS_START + 104)
  50 #define BSS_BootDrive            (BSS_START + 108) // 1 byte
  51 #define BSS_BootPartition        (BSS_START + 109) // 1 byte
  52
  53
  54 /* Realmode function IDs */
  55 #define FNID_Int386 0
  56 #define FNID_Reboot 1
  57 #define FNID_Relocator16Boot 2
  58 #define FNID_PxeCallApi 3
  59 #define FNID_PnpBiosGetDeviceNodeCount  4
  60 #define FNID_PnpBiosGetDeviceNode       5
  61
  62 /* Flag Masks */
  63 #define CR0_PE_SET    HEX(00000001)    /* OR this value with CR0 to enable pmode */
  64 #define CR0_PE_CLR    HEX(FFFFFFFE)    /* AND this value with CR0 to disable pmode */
  65
  66 /* Defines needed for switching between real and protected mode */
  67 //#ifdef _M_IX86
  68 #define NULL_DESC   HEX(00)    /* NULL descriptor */
  69 #define PMODE_CS    HEX(08)    /* PMode code selector, base 0 limit 4g */
  70 #define PMODE_DS    HEX(10)    /* PMode data selector, base 0 limit 4g */
  71 #define RMODE_CS    HEX(18)    /* RMode code selector, base 0 limit 64k */
  72 #define RMODE_DS    HEX(20)    /* RMode data selector, base 0 limit 64k */
  73 //#else
  74 /* Long mode selectors */
  75 #define LMODE_CS HEX(10)
  76 #define LMODE_DS HEX(18)
  77 #define CMODE_CS HEX(30)
  78 //#endif