int/com/src/syscalls/syscalls.c

   1 /***********************************************************************/
   2 /*                                                                     */
   3 /*  SYSCALLS.C:  System Calls for the newlib                                      */
   4 /*  most of this is from newlib-lpc and a Keil-demo                    */
   5 /*                                                                     */
   6 /*  These are "reentrant functions" as needed by                       */
   7 /*  the WinARM-newlib-config, see newlib-manual.                       */
   8 /*  Collected and modified by Martin Thomas                            */
   9 /*                                                                     */
  10 /***********************************************************************/
  11
  12
  13 #include <stdlib.h>
  14 #include <reent.h>
  15 #include <errno.h>
  16 #include <sys/stat.h>
  17
  18 _ssize_t _read_r(
  19     struct _reent *r,
  20     int file,
  21     void *ptr,
  22     size_t len)
  23 {
  24         /*
  25         unsigned char *p;
  26         while ( AT91F_US_RxReady((AT91PS_USART)AT91C_BASE_DBGU) == 0 ) {
  27                 ;
  28         }
  29
  30         p = ptr;
  31
  32         *p= AT91F_US_GetChar((AT91PS_USART)AT91C_BASE_DBGU);
  33     */
  34         return (_ssize_t)1;
  35 }
  36
  37
  38 _ssize_t _write_r (
  39     struct _reent *r,
  40     int file,
  41     const void *ptr,
  42     size_t len)
  43 {
  44         /*
  45         size_t todo;
  46         const unsigned char *p;
  47
  48         todo = len;
  49         p = ptr;
  50
  51         for( ; todo != 0; todo--) {
  52                 if ( *p == '\n' ) {
  53                         while (!AT91F_US_TxReady((AT91PS_USART)AT91C_BASE_DBGU)) {
  54                                 ;
  55                         }
  56                         AT91F_US_PutChar((AT91PS_USART)AT91C_BASE_DBGU, '\r');
  57                 }
  58                 while (!AT91F_US_TxReady((AT91PS_USART)AT91C_BASE_DBGU)) {
  59                         ;
  60                 }
  61                 AT91F_US_PutChar((AT91PS_USART)AT91C_BASE_DBGU, *p++);
  62     }
  63         */
  64         return (_ssize_t)len;                   // Number of bytes written.
  65 }
  66
  67
  68 int _close_r(
  69     struct _reent *r,
  70     int file)
  71 {
  72         return 0;
  73 }
  74
  75
  76 _off_t _lseek_r(
  77     struct _reent *r,
  78     int file,
  79     _off_t ptr,
  80     int dir)
  81 {
  82         return (_off_t)0;       /*  Always indicate we are at file beginning.  */
  83 }
  84
  85
  86 int _fstat_r(
  87     struct _reent *r,
  88     int file,
  89     struct stat *st)
  90 {
  91         /*  Always set as character device.                             */
  92         st->st_mode = S_IFCHR;
  93         /* assigned to strong type with implicit        */
  94         /* signed/unsigned conversion.  Required by     */
  95         /* newlib.                                      */
  96
  97         return 0;
  98 }
  99
 100
 101 int _isatty(int file); /* avoid warning */
 102
 103 int _isatty(int file)
 104 {
 105         return 1;
 106 }
 107
 108 void abort(void)
 109 {
 110         while(1);
 111 }
 112
 113 #if 0
 114 static void _exit (int n) {
 115 label:  goto label; /* endless loop */
 116 }
 117 #endif
 118
 119
 120 #ifdef USE_CHIBIOS
 121
 122 void * _sbrk_r(struct _reent *r, int incr)
 123 {
 124 #if CH_USE_MEMCORE
 125   void *p;
 126
 127   chDbgCheck(incr > 0, "_sbrk_r");
 128
 129   (void)r;
 130   p = chCoreAlloc((size_t)incr);
 131   if (p == NULL) {
 132     __errno_r(r) = ENOMEM;
 133     return (caddr_t)-1;
 134   }
 135   return (caddr_t)p;
 136 #else
 137   __errno_r(r) = ENOMEM;
 138   return (caddr_t)-1;
 139 #endif
 140 }
 141
 142
 143 #else
 144 /**** Locally used variables. ****/
 145 // mt: "cleaner": extern char* end;
 146 extern char end[];              /*  end is set in the linker command    */
 147                                 /* file and is the end of statically    */
 148                                 /* allocated data (thus start of heap). */
 149
 150 static char *heap_ptr;          /* Points to current end of the heap.   */
 151
 152 /************************** _sbrk_r *************************************
 153  * Support function. Adjusts end of heap to provide more memory to
 154  * memory allocator. Simple and dumb with no sanity checks.
 155
 156  *  struct _reent *r -- re-entrancy structure, used by newlib to
 157  *                      support multiple threads of operation.
 158  *  ptrdiff_t nbytes -- number of bytes to add.
 159  *                      Returns pointer to start of new heap area.
 160  *
 161  *  Note:  This implementation is not thread safe (despite taking a
 162  *         _reent structure as a parameter).
 163  *         Since _s_r is not used in the current implementation,
 164  *         the following messages must be suppressed.
 165  */
 166 void * _sbrk_r(
 167     struct _reent *_s_r,
 168     ptrdiff_t nbytes)
 169 {
 170         char  *base;            /*  errno should be set to  ENOMEM on error  */
 171
 172         if (!heap_ptr) {        /*  Initialize if first time through.  */
 173                 heap_ptr = end;
 174         }
 175         base = heap_ptr;        /*  Point to end of heap.  */
 176         heap_ptr += nbytes;     /*  Increase heap.  */
 177
 178         return base;            /*  Return pointer to start of new heap area.  */
 179 }
 180 #endif