Add multi file input

src/args.S

@@ -24,6 +24,8 @@ fetch_argc:
 # @param[out] a1: address of argv[a0].
 # @param[out] a2: sizeof(argv[a0]).
 fetch_argv:
+    addi sp, sp, -8
+    sd s0, 0(sp)
     mv s0, a0
 
     addi sp, sp, -16
@@ -38,6 +40,8 @@ fetch_argv:
     bltz a1, 2f # fail if a0 less than zero
     ld t0, sp_start
     addi t0, t0, 8
+    addi sp, sp, -8
+    sd s1, 0(sp)
     li s1, 0
 
     ld a0, 0(t0)
@@ -55,12 +59,15 @@ fetch_argv:
     mv a0, a1
     addi s1, s1, 1
     bne s1, s0, 1b # if we haven't retrieved the requested argument, go again
-    
+
     j 3f
 
     2:    
     li a0, 1 # fail
-    j 4f
+    ld s0, 0(sp)
+    addi sp, sp, 8
+    ret
+    
     3:
     mv s0, a1
     addi sp, sp, -16
@@ -79,6 +86,10 @@ fetch_argv:
     mv a1, s0
 
     4:
+    ld s1, 0(sp)
+    addi sp, sp, 8
+    ld s0, 0(sp)
+    addi sp, sp, 8
     ret