small and efficient c startup code (crt0) and standard library, lightweight replacement for libc suitible for arch linux users around the world

crt.h

#ifndef CRT_H_
#define CRT_H_
/*int main(const int argc, const char* const argv[]);*/
_Noreturn void main(void);
void* syscall3(void* arg1, void* arg2, void* arg3, int number);
#endif

crt.S

.text
.global _start, syscall3

_start:
    xorl %ebp, %ebp
    /* popq %rdi
     * movq %rsp, %rsi */
    /* call main */
    jmp main

    /* movl %eax, %edi
     * movl $60, %eax
     * syscall */

syscall3:
    movl %ecx, %eax
    syscall
    ret

x86_64 sysv abi document says that rsp is guaranteed to be 16-byte aligned at program startup, so there is no need to manually align it