Hello, wired

A wired program has no libc: no main, no printf. wired.h gives you the replacement for both, and this page shows the smallest program that uses them.

Code

main.c

#define WIRED_MAIN /* this file provides _start, memcpy and memset */
#include "wired.h"

int wired_main(int argc, char** argv) {
  (void)argc;
  (void)argv;
  wired_log_str("hello\n"); /* stderr */
  return 0;
}

Output

$ ./hello
hello

How it works

• #define WIRED_MAIN before #include "wired.h" emits the _start entry point and the memcpy/memset a -nostdlib binary needs. Define it in exactly one file.
• _start calls your wired_main(argc, argv); its return value becomes the exit status.
• wired_log_str writes a NUL-terminated string to stderr.

Build and run

Build the SDK archive once, then compile your file freestanding against it:

just lib
clang -target x86_64-linux-gnu -ffreestanding -fno-stack-protector \
      -fno-builtin -nostdlib -static \
      -Isrc -o hello main.c build/libwired.a
./hello

Every other page in this guide builds the same way.