diff --git a/bare-metal-bsp/libwrap/libwrap.mk b/bare-metal-bsp/libwrap/libwrap.mk
index fc5e8da..345e993 100644
--- a/bare-metal-bsp/libwrap/libwrap.mk
+++ b/bare-metal-bsp/libwrap/libwrap.mk
@@ -24,16 +24,36 @@ LIBWRAP_SRCS := \
 	sys/times.c \
 	sys/sbrk.c \
 	sys/_exit.c \
+	sys/puts.c \
 	misc/write_hex.c \
 	sys/printf.c
 
 LIBWRAP_SRCS := $(foreach f,$(LIBWRAP_SRCS),$(LIBWRAP_DIR)/$(f))
 LIBWRAP_OBJS := $(LIBWRAP_SRCS:.c=.o)
 
-LIBWRAP_SYMS := malloc free \
-	open lseek read write fstat stat close link unlink \
-	execve fork getpid kill wait \
-	isatty times sbrk _exit
+LIBWRAP_SYMS := \
+	malloc \
+	open \
+	lseek _lseek\
+	read _read\
+	write _write\
+	fstat _fstat\
+	stat \
+	close _close\
+	link \
+	unlink \
+	execve \
+	fork \
+	getpid \
+	kill \
+	wait \
+	isatty \
+	times \
+	sbrk _sbrk\
+	_exit \
+	puts _puts\
+	printf \
+	sprintf
 
 LIBWRAP := libwrap.a
 
diff --git a/bare-metal-bsp/libwrap/sys/_exit.c b/bare-metal-bsp/libwrap/sys/_exit.c
index 9a5f484..7dab930 100644
--- a/bare-metal-bsp/libwrap/sys/_exit.c
+++ b/bare-metal-bsp/libwrap/sys/_exit.c
@@ -5,6 +5,7 @@
 
 extern volatile uint32_t tohost;
 extern volatile uint32_t fromhost;
+void write_hex(int fd, uint32_t hex);
 
 void __wrap__exit(int code)
 {
diff --git a/bare-metal-bsp/libwrap/sys/close.c b/bare-metal-bsp/libwrap/sys/close.c
index e4f8e14..5f047c8 100644
--- a/bare-metal-bsp/libwrap/sys/close.c
+++ b/bare-metal-bsp/libwrap/sys/close.c
@@ -2,8 +2,12 @@
 
 #include <errno.h>
 #include "stub.h"
+#include "weak_under_alias.h"
 
 int __wrap_close(int fd)
 {
   return _stub(EBADF);
 }
+
+weak_under_alias(close);
+
diff --git a/bare-metal-bsp/libwrap/sys/fstat.c b/bare-metal-bsp/libwrap/sys/fstat.c
index 6ea3e6a..41ad12c 100644
--- a/bare-metal-bsp/libwrap/sys/fstat.c
+++ b/bare-metal-bsp/libwrap/sys/fstat.c
@@ -4,6 +4,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include "stub.h"
+#include "weak_under_alias.h"
 
 int __wrap_fstat(int fd, struct stat* st)
 {
@@ -14,3 +15,5 @@ int __wrap_fstat(int fd, struct stat* st)
 
   return _stub(EBADF);
 }
+
+weak_under_alias(fstat);
diff --git a/bare-metal-bsp/libwrap/sys/lseek.c b/bare-metal-bsp/libwrap/sys/lseek.c
index 46f58fa..74488c7 100644
--- a/bare-metal-bsp/libwrap/sys/lseek.c
+++ b/bare-metal-bsp/libwrap/sys/lseek.c
@@ -4,6 +4,7 @@
 #include <unistd.h>
 #include <sys/types.h>
 #include "stub.h"
+#include "weak_under_alias.h"
 
 off_t __wrap_lseek(int fd, off_t ptr, int dir)
 {
@@ -12,3 +13,6 @@ off_t __wrap_lseek(int fd, off_t ptr, int dir)
 
   return _stub(EBADF);
 }
+
+weak_under_alias(lseek);
+
diff --git a/bare-metal-bsp/libwrap/sys/puts.c b/bare-metal-bsp/libwrap/sys/puts.c
new file mode 100644
index 0000000..50d6437
--- /dev/null
+++ b/bare-metal-bsp/libwrap/sys/puts.c
@@ -0,0 +1,28 @@
+/* See LICENSE of license details. */
+
+#include <stdint.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/types.h>
+
+#include "platform.h"
+#include "stub.h"
+#include "weak_under_alias.h"
+
+int __wrap_puts(const char *s)
+{
+  while (*s != '\0') {
+    while (UART0_REG(UART_REG_TXFIFO) & 0x80000000) ;
+    UART0_REG(UART_REG_TXFIFO) = *s;
+
+    if (*s == '\n') {
+      while (UART0_REG(UART_REG_TXFIFO) & 0x80000000) ;
+      UART0_REG(UART_REG_TXFIFO) = '\r';
+    }
+
+    ++s;
+  }
+
+  return 0;
+}
+weak_under_alias(puts);
diff --git a/bare-metal-bsp/libwrap/sys/sbrk.c b/bare-metal-bsp/libwrap/sys/sbrk.c
index 6e6b36a..a43c191 100644
--- a/bare-metal-bsp/libwrap/sys/sbrk.c
+++ b/bare-metal-bsp/libwrap/sys/sbrk.c
@@ -1,6 +1,7 @@
 /* See LICENSE of license details. */
 
 #include <stddef.h>
+#include "weak_under_alias.h"
 
 void *__wrap_sbrk(ptrdiff_t incr)
 {
@@ -14,3 +15,5 @@ void *__wrap_sbrk(ptrdiff_t incr)
   curbrk += incr;
   return curbrk - incr;
 }
+
+weak_under_alias(sbrk);