diff --git a/Makefile b/Makefile
index b7204ed..c69639e 100644
--- a/Makefile
+++ b/Makefile
@@ -8,7 +8,7 @@ CC=${CROSSCOMPILE}gcc
 LD=${CROSSCOMPILE}ld
 OBJCOPY=${CROSSCOMPILE}objcopy
 OBJDUMP=${CROSSCOMPILE}objdump
-CFLAGS=-I. -O2 -ggdb -march=rv64imafdc -mabi=lp64d -Wall -mcmodel=medany -mexplicit-relocs
+CFLAGS=-I. -O2 -ggdb -march=rv64imafdc -mabi=lp64d -Wall -mcmodel=medany -mexplicit-relocs -Wno-main
 CCASFLAGS=-I. -mcmodel=medany -mexplicit-relocs
 LDFLAGS=-nostdlib -nostartfiles
 
@@ -52,7 +52,7 @@ asm: zsbl.asm fsbl.asm
 
 lib/version.c: .git/HEAD .git/index
 	echo "const char *gitid = \"$(shell git describe --always --dirty)\";" > lib/version.c
-	echo "const char *gitdate = \"$(shell git log -n 1 --date=short --format=format:"%ad.%h" HEAD)\";" >> lib/version.c
+	echo "const char *gitdate = \"$(shell git log -n 1 --date=short --format=format:"%ad.%h" --no-show-signature HEAD)\";" >> lib/version.c
 	echo "const char *gitversion = \"$(shell git rev-parse HEAD)\";" >> lib/version.c
 #	echo "const char *gitstatus = \"$(shell git status -s )\";" >> lib/version.c
 
@@ -73,7 +73,7 @@ fsbl/dtb.o: fsbl/ux00_fsbl.dtb
 zsbl/start.o: zsbl/ux00_zsbl.dtb
 
 %.bin: %.elf
-	$(OBJCOPY) -O binary $^ $@
+	$(OBJCOPY) -S -R .comment -R .note.gnu.build-id -O binary $^ $@
 
 %.asm: %.elf
 	$(OBJDUMP) -S $^ > $@
diff --git a/lib/strlen.c b/lib/strlen.c
index 565955f..3d6addf 100644
--- a/lib/strlen.c
+++ b/lib/strlen.c
@@ -17,6 +17,14 @@
 #include <string.h>
 #include <stdint.h>
 
+static __inline unsigned long detect_null(unsigned long w)
+{
+  unsigned long mask = 0x7f7f7f7f;
+  if (sizeof (long) == 8)
+    mask = ((mask << 16) << 16) | mask;
+  return ~(((w & mask) + mask) | w | mask);
+}
+
 size_t strlen(const char *str)
 {
   const char *start = str;
@@ -35,7 +43,7 @@ size_t strlen(const char *str)
     } while ((uintptr_t)str & (sizeof (long) - 1));
 
   unsigned long *ls = (unsigned long *)str;
-  while (!__libc_detect_null (*ls++))
+  while (!detect_null (*ls++))
     ;
   asm volatile ("" : "+r"(ls)); /* prevent "optimization" */