toolchain/gcc/libgloss/mn10300/cygmon.c

   1 /* cygmon.c -- Glue code for linking apps to run on top of Cygmon.
   2  *
   3  * Copyright (c) 1998, 1999, 2000, 2001 Red Hat, Inc.
   4  *
   5  * The authors hereby grant permission to use, copy, modify, distribute,
   6  * and license this software and its documentation for any purpose, provided
   7  * that existing copyright notices are retained in all copies and that this
   8  * notice is included verbatim in any distributions. No written agreement,
   9  * license, or royalty fee is required for any of the authorized uses.
  10  * Modifications to this software may be copyrighted by their authors
  11  * and need not follow the licensing terms described here, provided that
  12  * the new terms are clearly indicated on the first page of each file where
  13  * they apply.
  14  */
  15
  16 #include <errno.h>
  17
  18 // These need to be kept in sync with the definitions in Cygmon.
  19 #define SYS_meminfo     1001
  20 #include "syscall.h"
  21
  22 /* Structure filled in by get_mem_info.  Only the size field is
  23    actually used (by sbrk), so the others aren't even filled in.  */
  24 struct s_mem
  25 {
  26   unsigned int size;
  27   unsigned int icsize;
  28   unsigned int dcsize;
  29 };
  30
  31 // Perform a system call.
  32 // Unused parameters should be set to 0.
  33 int __trap0(unsigned long func, unsigned long p1, unsigned long p2, unsigned long p3)
  34 {
  35   int ret = 0;
  36 #ifdef __AM33__
  37   {
  38     register unsigned long d0 asm ("d0") = func;
  39     register unsigned long d1 asm ("d1") = p1;
  40     register unsigned long d2 asm ("d2") = p2;
  41     register unsigned long d3 asm ("d3") = p3;
  42     asm volatile ("    syscall 0\n"
  43                   "    nop"
  44                   : "+d" (d0) : "d" (d1), "d" (d2), "d" (d3) : "memory");
  45     ret = d0;
  46   }
  47 #endif
  48
  49   if (func == SYS_exit)
  50     {
  51       while (1)
  52         {
  53           asm volatile (" .byte 0xff ");  // trigger a breakpoint to drop back into Cygmon
  54         }
  55     }
  56
  57   if (ret != 0)
  58       errno = ret;
  59
  60   return ret;
  61 }
  62
  63 void *
  64 get_mem_info (mem)
  65      struct s_mem *mem;
  66 {
  67   unsigned long totmem = 0, topmem = 0;
  68   register int numbanks;
  69
  70   numbanks = __trap0(SYS_meminfo, (unsigned long)&totmem, (unsigned long)&topmem, 0);
  71   mem->size = totmem;
  72   return (void*)topmem;
  73 }