target/linux/adm8668/image/lzma-loader/src/stubs.c

   1 #include <exports.h>
   2
   3 #ifndef GCC_VERSION
   4 #define GCC_VERSION (__GNUC__ * 1000 + __GNUC_MINOR__)
   5 #endif /* GCC_VERSION */
   6
   7 /*
   8  * k0 ($26) holds the pointer to the global_data; t9 ($25) is a call-
   9  * clobbered register that is also used to set gp ($26). Note that the
  10  * jr instruction also executes the instruction immediately following
  11  * it; however, GCC/mips generates an additional `nop' after each asm
  12  * statement
  13  */
  14 #define EXPORT_FUNC(x) \
  15         asm volatile (                  \
  16 "       .globl " #x "\n"                \
  17 #x ":\n"                                \
  18 "       lw      $25, %0($26)\n"         \
  19 "       lw      $25, %1($25)\n"         \
  20 "       jr      $25\n"                  \
  21         : : "i"(offsetof(gd_t, jt)), "i"(XF_ ## x * sizeof(void *)) : "t9");
  22
  23 /* This function is necessary to prevent the compiler from
  24  * generating prologue/epilogue, preparing stack frame etc.
  25  * The stub functions are special, they do not use the stack
  26  * frame passed to them, but pass it intact to the actual
  27  * implementation. On the other hand, asm() statements with
  28  * arguments can be used only inside the functions (gcc limitation)
  29  */
  30 #if GCC_VERSION < 3004
  31 static
  32 #endif /* GCC_VERSION */
  33 void __attribute__((unused)) dummy(void)
  34 {
  35 #include <_exports.h>
  36 }
  37
  38 #if 0
  39 extern unsigned long __bss_start, _end;
  40
  41 void app_startup(char **argv)
  42 {
  43         unsigned long * cp = &__bss_start;
  44
  45         /* Zero out BSS */
  46         while (cp < &_end) {
  47                 *cp++ = 0;
  48         }
  49 }
  50 #endif
  51
  52 #undef EXPORT_FUNC