feat(sys): add sys lib

app/entry.s

@@ -1,29 +0,0 @@
-.global _start, syscall5
-
-
-_start: 
-    /* Load argc -> rdi, argv[0] -> rsi */
-    xor %rbp, %rbp
-    pop %rdi
-    mov %rsp, %rsi
-
-    and $0xFFFFFFFFFFFFFFF0, %rsp
-    
-    call main
-
-    /* Exit with ret val of main */
-    mov %rax, %rdi
-    mov $0x3C, %rax
-    syscall
-
-syscall5:
-    mov    %rdi, %rax /* %rax (syscall number)  = func param 1 (%rdi)    */
-    mov    %rsi, %rdi /* %rdi (syscall param 1) = func param 2 (%rsi)    */
-    mov    %rdx, %rsi /* %rsi (syscall param 2) = func param 3 (%rdx)    */
-    mov    %rcx, %rdx /* %rdx (syscall param 3) = func param 4 (%rcx)    */
-    mov    %r8,  %r10 /* %r10 (syscall param 4) = func param 5 (%r8)     */
-    mov    %r9,  %r8  /* %r8  (syscall param 5) = func param 6 (%r9)     */
-    syscall           /* Enter a syscall (return value in %rax)          */
-    ret               /* Return value is already in %rax, we can return. */
-    
-.section .note.GNU-stack,"",@progbits

app/nolibc.c

@@ -1,16 +1,4 @@
-void *syscall5(void *number, void *arg1, void *arg2, void *arg3, void *arg4,
-               void *arg5);
-
-typedef unsigned long int size_t;
-typedef long int ssize_t;
-
-static ssize_t write(int fd, void const *data, size_t nbytes) {
-  return (ssize_t)syscall5((void *)1, /* SYS_write, call number 1 */
-                           (void *)(size_t)fd, (void *)data, (void *)nbytes,
-                           0, /* Ignored */
-                           0  /* Ignored */
-  );
-}
+#include <c-libs/sys/syscall.h>
 
 int main() {
   write(0, "Hello World!\n", 13);