arch/arm-all/include/aros/genmodule-thumb2.h

   1 /*
   2     Copyright © 2016, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: genmodule-thumb2.h include file for arm-le systems in thumb2 mode
   6     Lang: english
   7 */
   8
   9 #ifndef AROS_ARM_GENMODULE_H
  10 #define AROS_ARM_GENMODULE_H
  11
  12 #include <exec/execbase.h>
  13
  14 /* Macros for generating library stub functions and aliases for stack libcalls. */
  15
  16 /******************* Linklib Side Thunks ******************/
  17
  18 /* Macro: AROS_GM_LIBFUNCSTUB(functionname, libbasename, lvo)
  19    This macro will generate code for a stub function for
  20    the function 'functionname' of lirary with libbase
  21    'libbasename' and 'lvo' number of the function in the
  22    vector table. lvo has to be a constant value (not a variable)
  23 */
  24 #define __AROS_GM_LIBFUNCSTUB(fname, libbasename, lvo)                  \
  25     void __attribute__((noreturn)) __ ## fname ## _ ## libbasename ## _wrapper(void)              \
  26     {                                                                   \
  27         asm volatile(                                                   \
  28             ".thumb \n"                                                 \
  29             ".weak " #fname "\n"                                        \
  30             ".type " #fname ", %%function\n"                            \
  31             #fname " :\n"                                               \
  32             /* r12 = libbase */                                         \
  33             "\tldr r12, 1f\n"                                           \
  34             "\tldr r12, [r12]\n"                                        \
  35             /* Compute function address and jump */                     \
  36             "\tsub.w r12, r12, #%c0\n"                                  \
  37             "\tbx r12\n"                                                \
  38             ".align 2\n"                                                \
  39             "1: .word " #libbasename "\n"                               \
  40             : : "i" ((lvo*LIB_VECTSIZE))                               \
  41         );                                                              \
  42         __builtin_unreachable();                                        \
  43     }
  44 #define AROS_GM_LIBFUNCSTUB(fname, libbasename, lvo) \
  45     __AROS_GM_LIBFUNCSTUB(fname, libbasename, lvo)
  46
  47 /* Macro: AROS_GM_RELLIBFUNCSTUB(functionname, libbasename, lvo)
  48    Same as AROS_GM_LIBFUNCSTUB but finds libbase at an offset in
  49    the current libbase
  50 */
  51 #define __AROS_GM_RELLIBFUNCSTUB(fname, libbasename, lvo)               \
  52     void __attribute__((noreturn)) __ ## fname ## _ ## libbasename ## _relwrapper(IPTR args)      \
  53     {                                                                   \
  54         asm volatile(                                                   \
  55             ".thumb \n"                                                 \
  56             ".weak " #fname "\n"                                        \
  57             ".type " #fname ", %%function\n"                            \
  58             #fname " :\n"                                               \
  59             /* return address is in lr register */                      \
  60             /* Up to four parameters are in r0 - r3 , the rest are on stack */ \
  61             "\tpush {r0, r1, r2, r3, lr}\n"                             \
  62             /* r0 = __aros_getoffsettable() */                          \
  63             "\tbl  __aros_getoffsettable\n"                             \
  64             /* r12 = libbase */                                         \
  65             "\tldr r1, 1f\n"                                            \
  66             "\tldr r1, [r1]\n"                                          \
  67             "\tldr r12, [r0, r1]\n"                                     \
  68             /* Restore original arguments */                            \
  69             "\tpop {r0, r1, r2, r3, lr}\n"                              \
  70             /* Compute function address and jump */                     \
  71             "\tsub.w r12, r12, #%c0\n"                                  \
  72             "\tbx r12\n"                                                \
  73             "1: .word __aros_rellib_offset_" #libbasename "\n"              \
  74             "2: .word __aros_getoffsettable\n"                          \
  75             : : "i" ((lvo*LIB_VECTSIZE))                                \
  76         );                                                              \
  77         __builtin_unreachable();                                        \
  78     }
  79 #define AROS_GM_RELLIBFUNCSTUB(fname, libbasename, lvo) \
  80     __AROS_GM_RELLIBFUNCSTUB(fname, libbasename, lvo)
  81
  82 /* Macro: AROS_GM_LIBFUNCALIAS(functionname, alias)
  83    This macro will generate an alias 'alias' for function
  84    'functionname'
  85 */
  86 #define __AROS_GM_LIBFUNCALIAS(fname, alias) \
  87     asm(".thumb \n"                 \
  88         ".weak " #alias "\n"        \
  89         "\t.set " #alias "," #fname \
  90     );
  91 #define AROS_GM_LIBFUNCALIAS(fname, alias) \
  92     __AROS_GM_LIBFUNCALIAS(fname, alias)
  93
  94 /******************* Library Side Thunks ******************/
  95
  96 /* This macro relies upon the fact that the
  97  * caller to a stack function will have passed in
  98  * the base in %r12, since the caller will
  99  * have used the AROS_LIBFUNCSTUB() macro.
 100  */
 101 #define __GM_STRINGIZE(x) #x
 102 #define __AROS_GM_STACKCALL(fname, libbasename, libfuncname)                    \
 103     void libfuncname(void);                                                     \
 104     void __attribute__((noreturn)) __ ## fname ## _stackcall(void)              \
 105     {                                                                           \
 106         asm volatile(                                                           \
 107             ".thumb \n"                                                         \
 108             "\t" __GM_STRINGIZE(libfuncname) " :\n"                             \
 109             /* Up to four parameters are in r0 - r3 , the rest are on stack */  \
 110             "\tpush {r0, r1, r2, r3, lr}\n"                                     \
 111             "\tmov  r0, r12\n"                                                  \
 112             "\tbl   __aros_setoffsettable\n"                                    \
 113             "\tpop  {r0, r1, r2, r3, lr}\n"                                     \
 114             "\tb   " #fname "\n"                                                \
 115         );                                                                      \
 116         __builtin_unreachable();                                                \
 117     }
 118
 119 #define AROS_GM_STACKCALL(fname, libbasename, lvo) \
 120      __AROS_GM_STACKCALL(fname, libbasename, AROS_SLIB_ENTRY(fname, libbasename, lvo))
 121
 122 /* Macro: AROS_GM_STACKALIAS(functionname, libbasename, lvo)
 123    This macro will generate an alias 'alias' for function
 124    'functionname'
 125 */
 126 #define __AROS_GM_STACKALIAS(fname, alias)          \
 127     void alias(void);                               \
 128     asm(".thumb \n"                                 \
 129         ".weak " __GM_STRINGIZE(alias) "\n"         \
 130         "\t.set " __GM_STRINGIZE(alias) "," #fname  \
 131     );
 132 #define AROS_GM_STACKALIAS(fname, libbasename, lvo) \
 133     __AROS_GM_STACKALIAS(fname, AROS_SLIB_ENTRY(fname, libbasename, lvo))
 134
 135 #endif /* AROS_ARM_GENMODULE_H */