kernel/cross.h

   1 /* memory access abstraction layer for forth kernel
   2  *
   3  * Copyright (C) 2005 Stefan Reinauer
   4  *
   5  * See the file "COPYING" for further information about
   6  * the copyright and warranty status of this work.
   7  */
   8
   9 #ifndef __CROSS_H
  10 #define __CROSS_H 1
  11
  12 /* The forthstrap compiler has to abstract the underlying dictionary
  13  * type: big/little endian, 32/64bit. All other binaries shall use
  14  * unchanged memory access for performance.
  15  */
  16
  17 /* byte swapping */
  18
  19 #ifndef SWAP_ENDIANNESS
  20
  21 /* trivial case - we don't have to change anything */
  22 #define read_ucell(addr) (*(ucell *)(addr))
  23 #define read_cell(addr)  (*(cell *)(addr))
  24 #define read_long(addr)  (*(u32 *)(addr))
  25 #define read_word(addr)  (*(u16 *)(addr))
  26 #define read_byte(addr)  (*(u8 *)(addr))
  27
  28 #define write_ucell(addr, value) {*(ucell *)(addr)=(value);}
  29 #define write_cell(addr, value)  {*(cell *)(addr)=(value);}
  30 #define write_long(addr, value)  {*(u32 *)(addr)=(value);}
  31 #define write_word(addr, value)  {*(u16 *)(addr)=(value);}
  32 #define write_byte(addr, value)  {*(u8 *)(addr)=(value);}
  33
  34 #define target_ucell(x) (x)
  35 #define target_cell(x) (x)
  36 #define target_long(x) (x)
  37 #define target_ulong(x) (x)
  38
  39 #else /* SWAP_ENDIANNESS */
  40
  41 #define target_word(value) ( (((value)>>8)&0xff) | (((value)&0xff)<<8) )
  42 #define target_long(value) ( (((value)&0xff000000)>>24)|(((value)&0x00ff0000)>>8)|(((value)&0xff00)<<8)|(((value)&0xff)<<24) )
  43 #define target_ulong(value) (target_long(value))
  44
  45 #if BITS==32
  46 #define target_ucell(value) ((ucell)target_long(value))
  47 #define target_cell(value) ((cell)target_long(value))
  48 #elif BITS==64
  49 #define target_ucell(value)                                             \
  50     ((((ucell)target_long((value) & 0xffffffff)) << 32) |               \
  51      ((ucell)target_long((value) >> 32)))
  52 #define target_cell(value)                                              \
  53     ((((cell)target_long((value) & 0xffffffff)) << 32) |                \
  54      ((cell)target_long((value) >> 32)))
  55 #else
  56 #error "Endianness not supported. Please report."
  57 #endif
  58
  59 #define read_ucell(addr) target_ucell(*(ucell *)(addr))
  60 #define read_cell(addr)  target_cell(*(cell *)(addr))
  61 #define read_long(addr)  target_long(*(u32 *)(addr))
  62 #define read_word(addr)  target_word(*(u16 *)(addr))
  63 #define read_byte(addr)  (*(u8 *)(addr))
  64
  65 #define write_ucell(addr, value) {*(ucell *)(addr)=target_ucell(value);}
  66 #define write_cell(addr, value)  {*(cell *)(addr)=target_cell(value);}
  67 #define write_long(addr, value)  {*(u32 *)(addr)=target_long(value);}
  68 #define write_word(addr, value)  {*(u16 *)(addr)=target_word(value);}
  69 #define write_byte(addr, value)  {*(u8 *)(addr)=(value);}
  70 #endif
  71
  72 #ifdef CONFIG_LITTLE_ENDIAN
  73 #define unaligned_read_word(addr) \
  74             (read_byte(addr)|(read_byte((u8 *)addr+1)<<8))
  75
  76 #define unaligned_read_long(addr) \
  77             (unaligned_read_word(addr)|(unaligned_read_word((u8 *)addr+2)<<16))
  78
  79 #define unaligned_write_word(addr, value) \
  80         write_byte(addr, (value & 0xff)); write_byte((u8 *)(addr+1), (value>>8))
  81
  82 #define unaligned_write_long(addr, value) \
  83         unaligned_write_word(addr, (value & 0xffff)); \
  84         unaligned_write_word((addr + 2), (value >> 16))
  85
  86 #endif
  87
  88 #ifdef CONFIG_BIG_ENDIAN
  89 #define unaligned_read_word(addr) \
  90             ((read_byte(addr)<<8)|read_byte((u8 *)addr+1))
  91
  92 #define unaligned_read_long(addr) \
  93             ((unaligned_read_word(addr)<<16)|unaligned_read_word((u8 *)addr+2))
  94
  95 #define unaligned_write_word(addr, value) \
  96         write_byte(addr, (value >> 8)); write_byte((u8 *)(addr+1), (value & 0xff))
  97
  98 #define unaligned_write_long(addr, value) \
  99         unaligned_write_word(addr, (value >> 16)); \
 100         unaligned_write_word((addr + 2), (value & 0xffff))
 101 #endif
 102
 103 /* bit width handling */
 104
 105 #ifdef NATIVE_BITWIDTH_EQUALS_HOST_BITWIDTH
 106 #if BITS==32
 107 #define FMT_CELL_x "x"
 108 #define FMT_CELL_d "d"
 109 #else
 110 #define FMT_CELL_x "llx"
 111 #define FMT_CELL_d "lld"
 112 #endif
 113 #endif
 114
 115 #ifdef NATIVE_BITWIDTH_SMALLER_THAN_HOST_BITWIDTH
 116 extern unsigned long base_address;
 117 #define FMT_CELL_x "x"
 118 #define FMT_CELL_d "d"
 119 #endif
 120
 121 #ifdef NATIVE_BITWIDTH_LARGER_THAN_HOST_BITWIDTH
 122 #define FMT_CELL_x "llx"
 123 #define FMT_CELL_d "lld"
 124 #endif
 125
 126 #endif