1 files changed, 105 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/core/rllpack.c b/contrib/syslinux-4.02/core/rllpack.c
new file mode 100644
index 0000000..bb9f046
--- /dev/null
+++ b/contrib/syslinux-4.02/core/rllpack.c
@@ -0,0 +1,105 @@
+/* ----------------------------------------------------------------------- *
+ *
+ *   Copyright 2007-2009 H. Peter Anvin - All Rights Reserved
+ *   Copyright 2009 Intel Corporation; author: H. Peter Anvin
+ *
+ *   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., 51 Franklin St, Fifth Floor,
+ *   Boston MA 02110-1301, USA; either version 2 of the License, or
+ *   (at your option) any later version; incorporated herein by reference.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * rllpack.inc
+ *
+ * Very simple RLL compressor/decompressor, used to pack binary structures
+ * together.
+ *
+ * Format of leading byte
+ * 1-128	= x verbatim bytes follow
+ * 129-223	= (x-126) times subsequent byte
+ * 224-255	= (x-224)*256+(next byte) times the following byte
+ * 0		= end of data
+ *
+ * These structures are stored *in reverse order* in high memory.
+ * High memory pointers point to one byte beyond the end.
+ */
+
+#include <com32.h>
+#include <stddef.h>
+#include <string.h>
+
+void rllpack(com32sys_t * regs)
+{
+    uint8_t *i = (uint8_t *) (regs->esi.l);
+    uint8_t *o = (uint8_t *) (regs->edi.l);
+    size_t cnt = regs->ecx.l;
+    size_t run, vrun, tcnt;
+    uint8_t *hdr = NULL;
+    uint8_t c;
+
+    vrun = (size_t)-1;
+    while (cnt) {
+	c = *i;
+
+	run = 1;
+	tcnt = (cnt > 8191) ? 8191 : cnt;
+	while (run < tcnt && i[run] == c)
+	    run++;
+
+	if (run < 3) {
+	    if (vrun >= 128) {
+		hdr = --o;
+		vrun = 0;
+	    }
+	    *--o = c;
+	    *hdr = ++vrun;
+	    i++;
+	    cnt--;
+	} else {
+	    if (run < 224 - 126) {
+		*--o = run + 126;
+	    } else {
+		o -= 2;
+		*(uint16_t *) o = run + (224 << 8);
+	    }
+	    *--o = c;
+	    vrun = (size_t)-1;
+	    i += run;
+	    cnt -= run;
+	}
+    }
+    *--o = 0;
+
+    regs->esi.l = (size_t)i;
+    regs->edi.l = (size_t)o;
+}
+
+void rllunpack(com32sys_t * regs)
+{
+    uint8_t *i = (uint8_t *) regs->esi.l;
+    uint8_t *o = (uint8_t *) regs->edi.l;
+    uint8_t c;
+    size_t n;
+
+    while ((c = *--i)) {
+	if (c <= 128) {
+	    while (c--)
+		*o++ = *--i;
+	} else {
+	    if (c < 224)
+		n = c - 126;
+	    else
+		n = ((c - 224) << 8) + *--i;
+	    c = *--i;
+	    while (n--)
+		*o++ = c;
+	}
+    }
+
+    regs->esi.l = (size_t)i;
+    regs->ecx.l = (size_t)o - regs->edi.l;
+    regs->edi.l = (size_t)o;
+}