3 files changed, 41 insertions, 2 deletions

diff --git a/com32/lib/Makefile b/com32/lib/Makefile
index 57348a8d..50862e00 100644
--- a/com32/lib/Makefile
+++ b/com32/lib/Makefile
@@ -151,7 +151,9 @@ LIBOTHER_OBJS = \
 	pci/readb.o pci/readw.o pci/readl.o pci/readbios.o		\
 	pci/writeb.o pci/writew.o pci/writel.o pci/writebios.o		\
 	\
-	sys/x86_init_fpu.o math/pow.o math/strtod.o
+	sys/x86_init_fpu.o math/pow.o math/strtod.o			\
+	\
+	syslinux/memscan.o
 	
 MINLIBOBJS = \
 	$(LIBOTHER_OBJS) \
diff --git a/com32/lib/free.c b/com32/lib/free.c
index f8a2e1f4..a91ad8ef 100644
--- a/com32/lib/free.c
+++ b/com32/lib/free.c
@@ -79,6 +79,43 @@ void free(void *ptr)
   /* Here we could insert code to return memory to the system. */
 }
 
+/*
+ * This is used to insert a block which is not previously on the
+ * free list.  Only the a.size field of the arena header is assumed
+ * to be valid.
+ */
+void __inject_free_block(struct free_arena_header *ah)
+{
+    struct free_arena_header *nah;
+    size_t a_end = (size_t) ah + ARENA_SIZE_GET(ah->a.attrs);
+    size_t n_end;
+
+    for (nah = __malloc_head.a.next; ARENA_TYPE_GET(nah->a.attrs) != ARENA_TYPE_HEAD;
+         nah = nah->a.next) {
+        n_end = (size_t) nah + ARENA_SIZE_GET(nah->a.attrs);
+
+        /* Is nah entirely beyond this block? */
+        if ((size_t) nah >= a_end)
+            break;
+
+        /* Is this block entirely beyond nah? */
+        if ((size_t) ah >= n_end)
+            continue;
+
+        /* Otherwise we have some sort of overlap - reject this block */
+        return;
+    }
+
+    /* Now, nah should point to the successor block */
+    ah->a.next = nah;
+    ah->a.prev = nah->a.prev;
+    nah->a.prev = ah;
+    ah->a.prev->a.next = ah;
+
+    __free_block(ah);
+}
+
+
 void __free_tagged(void *tag) {
 	struct free_arena_header *fp, *nfp;
 
diff --git a/com32/lib/malloc.c b/com32/lib/malloc.c
index 4b113221..ff6e5b9e 100644
--- a/com32/lib/malloc.c
+++ b/com32/lib/malloc.c
@@ -64,7 +64,7 @@ static int consider_memory_area(void *dummy, addr_t start,
 
 	    if (len >= 2 * sizeof(struct arena_header)) {
 		fp = (struct free_arena_header *)start;
-		fp->a.size = len;
+		ARENA_SIZE_SET(fp->a.attrs, len);
 		__inject_free_block(fp);
 	    }
 	}