Created small static library to wrap system call ABI

src/x86/do_syscall.S

@@ -0,0 +1,19 @@
+.global _do_syscall
+.type _do_syscall, @function
+_do_syscall:
+    push %ebp
+    mov %esp, %ebp
+    push %esi
+    push %edi
+    push %ebx
+    mov 0x08(%ebp), %eax
+    mov 0x0C(%ebp), %ebx
+    mov 0x10(%ebp), %ecx
+    mov 0x14(%ebp), %edx
+    int $0x80
+    pop %ebx
+    pop %edi
+    pop %esi
+    pop %ebp
+    ret
+.size _do_syscall, . - _do_syscall

src/x86/preempt.S

@@ -20,7 +20,7 @@ isr_syscall:
     mov %ax, %es
     mov %ax, %fs
     mov %ax, %gs
-    call do_syscall
+    call kernel_do_syscall
     mov %ebp, %esp
     mov $0x23, %cx
     mov %cx, %ds