Finish the shuffle and boot interface, and add an ELF loading module.

The shuffle and boot interface, including the library support, should now
work as advertised.  Add an ELF-loading module as a demo, and it's probably
useful for someone, too.

1 files changed, 21 insertions, 11 deletions

diff --git a/com32/lib/syslinux/shuffle.c b/com32/lib/syslinux/shuffle.c
index ad6e7d06..22719544 100644
--- a/com32/lib/syslinux/shuffle.c
+++ b/com32/lib/syslinux/shuffle.c
@@ -42,23 +42,21 @@ struct shuffle_descriptor {
   uint32_t dst, src, len;
 };
 
-int syslinux_prepare_shuffle(struct syslinux_movelist *fraglist)
+int syslinux_prepare_shuffle(struct syslinux_movelist *fraglist,
+			     struct syslinux_memmap *memmap)
 {
-  struct syslinux_movelist *moves = NULL, *freelist = NULL, *mp;
-  int n;
+  struct syslinux_movelist *moves = NULL, *mp;
+  struct syslinux_memmap *ml;
   struct shuffle_descriptor *dp;
   int np, rv = -1;
 
-  freelist = syslinux_memory_map();
-  if (!freelist)
-    goto bail;
-
-  if (syslinux_compute_movelist(&moves, fraglist, freelist))
+  if (syslinux_compute_movelist(&moves, fraglist, memmap))
     goto bail;
 
   dp = __com32.cs_bounce;
   np = 0;
 
+  /* Copy the move sequence into the bounce buffer */
   for (mp = moves; mp; mp = mp->next) {
     if (np >= 65536/12)
       goto bail;		/* Way too many descriptors... */
@@ -66,14 +64,26 @@ int syslinux_prepare_shuffle(struct syslinux_movelist *fraglist)
     dp->dst = mp->dst;
     dp->src = mp->src;
     dp->len = mp->len;
-    np++;
+    dp++; np++;
+  }
+
+  /* Copy any zeroing operations into the bounce buffer */
+  for (ml = memmap; ml->type != SMT_END; ml = ml->next) {
+    if (ml->type == SMT_ZERO) {
+      if (np >= 65536/12)
+	goto bail;
+
+      dp->dst = ml->start;
+      dp->src = (addr_t)-1;	/* bzero this region */
+      dp->len = ml->next->start - ml->start;
+      dp++; np++;
+    }
   }
 
   rv = np;
 
  bail:
-  if (freelist)
-    syslinux_free_movelist(freelist);
+  /* This is safe only because free() doesn't use the bounce buffer!!!! */
   if (moves)
     syslinux_free_movelist(moves);