1 files changed, 49 insertions, 0 deletions
diff --git a/util/nvramtool/win32mmap.c b/util/nvramtool/win32mmap.c
new file mode 100644
index 0000000000..f44dec88fc
--- /dev/null
+++ b/util/nvramtool/win32mmap.c
@@ -0,0 +1,49 @@
+#include "common.h"
+#include <windows.h>
+
+static inline size_t xsize_t(off_t len)
+{
+        if (len > (size_t) len)
+                die("Cannot handle files this big");
+        return (size_t)len;
+}
+
+void *win32_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
+{
+	HANDLE hmap;
+	void *temp;
+	off_t len;
+	struct stat st;
+	uint64_t o = offset;
+	uint32_t l = o & 0xFFFFFFFF;
+	uint32_t h = (o >> 32) & 0xFFFFFFFF;
+
+	if (!fstat(fd, &st))
+		len = st.st_size;
+	else
+		printf("mmap: could not determine filesize");
+
+	if ((length + offset) > len)
+		length = xsize_t(len - offset);
+
+	if (!(flags & MAP_PRIVATE))
+		printf("Invalid usage of mmap when built with USE_WIN32_MMAP");
+
+	hmap = CreateFileMapping((HANDLE)_get_osfhandle(fd), 0, PAGE_WRITECOPY,
+		0, 0, 0);
+
+	if (!hmap)
+		return MAP_FAILED;
+
+	temp = MapViewOfFileEx(hmap, FILE_MAP_COPY, h, l, length, start);
+
+	if (!CloseHandle(hmap))
+		printf("unable to close file mapping handle");
+
+	return temp ? temp : MAP_FAILED;
+}
+
+int win32_munmap(void *start, size_t length)
+{
+	return !UnmapViewOfFile(start);
+}