libogc/sbrk.c

   1 #include <_ansi.h>
   2 #include <_syslist.h>
   3 #include <stdlib.h>
   4 #include <unistd.h>
   5 #include <reent.h>
   6 #include <errno.h>
   7
   8 #include "asm.h"
   9 #include "processor.h"
  10 #include "system.h"
  11
  12 #if defined(HW_RVL)
  13 u32 MALLOC_MEM2 __attribute__((weak)) = 1;
  14 #endif
  15
  16 void* _DEFUN(__libogc_sbrk_r,(ptr,incr),
  17                          struct _reent *ptr _AND
  18                          ptrdiff_t incr)
  19 {
  20         u32 level;
  21         char *heap_end = 0;
  22         char *prev_heap = 0;
  23 #if defined(HW_RVL)
  24         static char *mem2_start = NULL;
  25 #endif
  26
  27         _CPU_ISR_Disable(level);
  28 #if defined(HW_RVL)
  29         if(MALLOC_MEM2) {
  30                 // use MEM2 aswell for malloc
  31                 if(mem2_start==NULL)
  32                         heap_end = (char*)SYS_GetArenaLo();
  33                 else
  34                         heap_end = (char*)SYS_GetArena2Lo();
  35
  36                 if(mem2_start) {
  37                         // we're in MEM2
  38                         if((heap_end+incr)>(char*)SYS_GetArena2Hi()) {
  39                                 // out of MEM2 case
  40                                 ptr->_errno = ENOMEM;
  41                                 prev_heap = (char *)-1;
  42                         } else if ((heap_end+incr) < mem2_start) {
  43                                 // trying to sbrk() back below the MEM2 start barrier
  44                                 ptr->_errno = EINVAL;
  45                                 prev_heap = (char *)-1;
  46                         } else {
  47                                 // success case
  48                                 prev_heap = heap_end;
  49                                 SYS_SetArena2Lo((void*)(heap_end+incr));
  50                         }
  51                         // if MEM2 area is exactly at the barrier, transition back to MEM1 again
  52                         if(SYS_GetArena2Lo() == mem2_start) mem2_start = NULL;
  53                 } else {
  54                         // we're in MEM1
  55                         if((heap_end+incr)>(char*)SYS_GetArenaHi()) {
  56                                 // out of MEM1, transition into MEM2
  57                                 if(((char*)SYS_GetArena2Lo() + incr) > (char*)SYS_GetArena2Hi()) {
  58                                         // this increment doesn't fit in available MEM2
  59                                         ptr->_errno = ENOMEM;
  60                                         prev_heap = (char *)-1;
  61                                 } else {
  62                                         // MEM2 is available, move into it
  63                                         mem2_start = heap_end = prev_heap = SYS_GetArena2Lo();
  64                                         SYS_SetArena2Lo((void*)(heap_end+incr));
  65                                 }
  66                         } else {
  67                                 // MEM1 is available (or we're freeing memory)
  68                                 prev_heap = heap_end;
  69                                 SYS_SetArenaLo((void*)(heap_end+incr));
  70                         }
  71                 }
  72         } else {
  73 #endif
  74                 heap_end = (char*)SYS_GetArenaLo();
  75
  76                 if((heap_end+incr)>(char*)SYS_GetArenaHi()) {
  77
  78                         ptr->_errno = ENOMEM;
  79                         prev_heap = (char *)-1;
  80
  81                 } else {
  82
  83                         prev_heap = heap_end;
  84                         SYS_SetArenaLo((void*)(heap_end+incr));
  85                 }
  86 #if defined(HW_RVL)
  87         }
  88 #endif
  89         _CPU_ISR_Restore(level);
  90
  91         return (void*)prev_heap;
  92 }