I tried the following commands which are supposed to work, but didn't. Does anybody know what is wrong? Thanks. https://blogs.oracle.com/ksplice/entry/hello_from_a_libc_free $ cat test.c #include <stdio.h> int main() { printf("Hello World\n"); } $ gcc -nostdlib -o test_nostdlib test.c /usr/bin/ld: warning: cannot find entry symbol _start; defaulting to 0000000000400144 /tmp/ccZBi5G9.o: In function `main': test.c:(.text+0xa): undefined reference to `puts' collect2: error: ld returned 1 exit status -- Regards, Peng