Answer by Zan Lynx for Dropping C library on Linux w/GCC

Here is what I got:

#include <sys/syscall.h>// Copied from MUSL libc// There are more at// http://git.musl-libc.org/cgit/musl/tree/arch/x86_64/syscall_arch.hstatic __inline long __syscall1(long n, long a1) {  unsigned long ret;  __asm__ __volatile__("syscall"                       : "=a"(ret)                       : "a"(n), "D"(a1)                       : "rcx", "r11", "memory");  return ret;}void do_exit(int status) { __syscall1(SYS_exit, status); }void entry() { do_exit(5); }

Saved as syscall.c and compiled with

cc -Wall -W -pedantic -static -O3 -march=native -flto -fno-fat-lto-objects  -fPIC -fPIE -fstack-protector-strong -std=gnu18 -nostdlib -e entry  syscall.c   -o syscall

And this is the entire disassembly of the 9,224 byte program:

0000000000001000 <entry>:    1000:   f3 0f 1e fa             endbr64    1004:   b8 3c 00 00 00          mov    $0x3c,%eax    1009:   bf 05 00 00 00          mov    $0x5,%edi    100e:   0f 05                   syscall    1010:   c3                      retq