Refactor libc stubs into libwrap

The --wrap feature of GNU ld supports a cleaner framework for linking in
alternative implementations of libc functions without cpp hacks.
Place wrappers in separate object files to reduce static code size.

1 files changed, 17 insertions, 0 deletions

diff --git a/bsp/libwrap/stdlib/malloc.c b/bsp/libwrap/stdlib/malloc.c
new file mode 100644
index 0000000..8f4f432
--- /dev/null
+++ b/bsp/libwrap/stdlib/malloc.c
@@ -0,0 +1,17 @@
+/* See LICENSE for license details. */
+
+/* These functions are intended for embedded RV32 systems and are
+   obviously incorrect in general. */
+
+void* __wrap_malloc(unsigned long sz)
+{
+  extern void* sbrk(long);
+  void* res = sbrk(sz);
+  if ((long)res == -1)
+    return 0;
+  return res;
+}
+
+void __wrap_free(void* ptr)
+{
+}