1 files changed, 107 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/memdisk/e820func.c b/contrib/syslinux-4.02/memdisk/e820func.c
new file mode 100644
index 0000000..13c0a6f
--- /dev/null
+++ b/contrib/syslinux-4.02/memdisk/e820func.c
@@ -0,0 +1,107 @@
+/* ----------------------------------------------------------------------- *
+ *
+ *   Copyright 2001-2008 H. Peter Anvin - All Rights Reserved
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
+ *   Boston MA 02111-1307, USA; either version 2 of the License, or
+ *   (at your option) any later version; incorporated herein by reference.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * e820func.c
+ *
+ * E820 range database manager
+ */
+
+#include <stdint.h>
+#ifdef TEST
+#include <string.h>
+#else
+#include "memdisk.h"		/* For memset() */
+#endif
+#include "e820.h"
+
+#define MAXRANGES	1024
+/* All of memory starts out as one range of "indeterminate" type */
+struct e820range ranges[MAXRANGES];
+int nranges;
+
+void e820map_init(void)
+{
+    memset(ranges, 0, sizeof(ranges));
+    nranges = 1;
+    ranges[1].type = -1U;
+}
+
+static void insertrange_at(int where, uint64_t start, uint32_t type)
+{
+    int i;
+
+    for (i = nranges; i > where; i--)
+	ranges[i] = ranges[i - 1];
+
+    ranges[where].start = start;
+    ranges[where].type = type;
+
+    nranges++;
+    ranges[nranges].start = 0ULL;
+    ranges[nranges].type = -1U;
+}
+
+void insertrange(uint64_t start, uint64_t len, uint32_t type)
+{
+    uint64_t last;
+    uint32_t oldtype;
+    int i, j;
+
+    /* Remove this to make len == 0 mean all of memory */
+    if (len == 0)
+	return;			/* Nothing to insert */
+
+    last = start + len - 1;	/* May roll over */
+
+    i = 0;
+    oldtype = -2U;
+    while (start > ranges[i].start && ranges[i].type != -1U) {
+	oldtype = ranges[i].type;
+	i++;
+    }
+
+    /* Consider the replacement policy.  This current one is "overwrite." */
+
+    if (start < ranges[i].start || ranges[i].type == -1U)
+	insertrange_at(i++, start, type);
+
+    while (i == 0 || last > ranges[i].start - 1) {
+	oldtype = ranges[i].type;
+	ranges[i].type = type;
+	i++;
+    }
+
+    if (last < ranges[i].start - 1)
+	insertrange_at(i, last + 1, oldtype);
+
+    /* Now the map is correct, but quite possibly not optimal.  Scan the
+       map for ranges which are redundant and remove them. */
+    i = j = 1;
+    oldtype = ranges[0].type;
+    while (i < nranges) {
+	if (ranges[i].type == oldtype) {
+	    i++;
+	} else {
+	    oldtype = ranges[i].type;
+	    if (i != j)
+		ranges[j] = ranges[i];
+	    i++;
+	    j++;
+	}
+    }
+
+    if (i != j) {
+	ranges[j] = ranges[i];	/* Termination sentinel copy */
+	nranges -= (i - j);
+    }
+}