1 files changed, 116 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/com32/lib/syslinux/setadv.c b/contrib/syslinux-4.02/com32/lib/syslinux/setadv.c
new file mode 100644
index 0000000..40f00a4
--- /dev/null
+++ b/contrib/syslinux-4.02/com32/lib/syslinux/setadv.c
@@ -0,0 +1,116 @@
+/* ----------------------------------------------------------------------- *
+ *
+ *   Copyright 2007-2008 H. Peter Anvin - All Rights Reserved
+ *   Copyright 2009 Intel Corporation; author: H. Peter Anvin
+ *
+ *   Permission is hereby granted, free of charge, to any person
+ *   obtaining a copy of this software and associated documentation
+ *   files (the "Software"), to deal in the Software without
+ *   restriction, including without limitation the rights to use,
+ *   copy, modify, merge, publish, distribute, sublicense, and/or
+ *   sell copies of the Software, and to permit persons to whom
+ *   the Software is furnished to do so, subject to the following
+ *   conditions:
+ *
+ *   The above copyright notice and this permission notice shall
+ *   be included in all copies or substantial portions of the Software.
+ *
+ *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ *   OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ *   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ *   HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ *   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ *   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ *   OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * syslinux/setadv.c
+ *
+ * (Over)write a data item in the auxilliary data vector.  To
+ * delete an item, set its length to zero.
+ *
+ * Return 0 on success, -1 on error, and set errno.
+ *
+ * NOTE: Data is not written to disk unless
+ * syslinux_adv_write() is called.
+ */
+
+#include <syslinux/adv.h>
+#include <klibc/compiler.h>
+#include <inttypes.h>
+#include <string.h>
+#include <errno.h>
+#include <alloca.h>
+
+int syslinux_setadv(int tag, size_t size, const void *data)
+{
+    uint8_t *p, *advtmp;
+    size_t rleft, left;
+
+    if ((unsigned)tag - 1 > 254) {
+	errno = EINVAL;
+	return -1;		/* Impossible tag value */
+    }
+
+    if (size > 255) {
+	errno = ENOSPC;		/* Max 255 bytes for a data item */
+	return -1;
+    }
+
+    rleft = left = syslinux_adv_size();
+    p = advtmp = alloca(left);
+    memcpy(p, syslinux_adv_ptr(), left);	/* Make working copy */
+
+    while (rleft >= 2) {
+	uint8_t ptag = p[0];
+	size_t plen = p[1] + 2;
+
+	if (ptag == ADV_END)
+	    break;
+
+	if (ptag == tag) {
+	    /* Found our tag.  Delete it. */
+
+	    if (plen >= rleft) {
+		/* Entire remainder is our tag */
+		break;
+	    }
+	    memmove(p, p + plen, rleft - plen);
+	    rleft -= plen;	/* Fewer bytes to read, but not to write */
+	} else {
+	    /* Not our tag */
+	    if (plen > rleft)
+		break;		/* Corrupt tag (overrun) - overwrite it */
+
+	    left -= plen;
+	    rleft -= plen;
+	    p += plen;
+	}
+    }
+
+    /* Now (p, left) reflects the position to write in and how much space
+       we have for our data. */
+
+    if (size) {
+	if (left < size + 2) {
+	    errno = ENOSPC;	/* Not enough space for data */
+	    return -1;
+	}
+
+	*p++ = tag;
+	*p++ = size;
+	memcpy(p, data, size);
+	p += size;
+	left -= size + 2;
+    }
+
+    memset(p, 0, left);
+
+    /* If we got here, everything went OK, commit the write to low memory */
+    memcpy(syslinux_adv_ptr(), advtmp, syslinux_adv_size());
+
+    return 0;
+}