util/nvramtool/win32mmap.c

   1 #include "common.h"
   2 #include <windows.h>
   3
   4 static inline size_t xsize_t(off_t len)
   5 {
   6         if (len > (size_t) len)
   7                 die("Cannot handle files this big");
   8         return (size_t)len;
   9 }
  10
  11 void *win32_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
  12 {
  13         HANDLE hmap;
  14         void *temp;
  15         off_t len;
  16         struct stat st;
  17         uint64_t o = offset;
  18         uint32_t l = o & 0xFFFFFFFF;
  19         uint32_t h = (o >> 32) & 0xFFFFFFFF;
  20
  21         if (!fstat(fd, &st))
  22                 len = st.st_size;
  23         else
  24                 printf("mmap: could not determine filesize");
  25
  26         if ((length + offset) > len)
  27                 length = xsize_t(len - offset);
  28
  29         if (!(flags & MAP_PRIVATE))
  30                 printf("Invalid usage of mmap when built with USE_WIN32_MMAP");
  31
  32         hmap = CreateFileMapping((HANDLE)_get_osfhandle(fd), 0, PAGE_WRITECOPY,
  33                 0, 0, 0);
  34
  35         if (!hmap)
  36                 return MAP_FAILED;
  37
  38         temp = MapViewOfFileEx(hmap, FILE_MAP_COPY, h, l, length, start);
  39
  40         if (!CloseHandle(hmap))
  41                 printf("unable to close file mapping handle");
  42
  43         return temp ? temp : MAP_FAILED;
  44 }
  45
  46 int win32_munmap(void *start, size_t length)
  47 {
  48         return !UnmapViewOfFile(start);
  49 }