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, 19 insertions, 0 deletions

diff --git a/bsp/libwrap/misc/write_hex.c b/bsp/libwrap/misc/write_hex.c
new file mode 100644
index 0000000..e678bdc
--- /dev/null
+++ b/bsp/libwrap/misc/write_hex.c
@@ -0,0 +1,19 @@
+/* See LICENSE of license details. */
+
+#include <stdint.h>
+#include <unistd.h>
+#include "platform.h"
+
+void write_hex(int fd, uint32_t hex)
+{
+  uint8_t ii;
+  uint8_t jj;
+  char towrite;
+  write(fd , "0x", 2);
+  for (ii = 8 ; ii > 0; ii--) {
+    jj = ii - 1;
+    uint8_t digit = ((hex & (0xF << (jj*4))) >> (jj*4));
+    towrite = digit < 0xA ? ('0' + digit) : ('A' +  (digit - 0xA));
+    write(fd, &towrite, 1);
+  }
+}