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)
@@ -60,7 +64,10 @@ fetch_argv:
 
     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
 
 

src/main.S

@@ -13,12 +13,21 @@ _start:
     call save_sp
     call fetch_argc
     li t0, 1
-    ble a1, t0, 1f # return 1 on no file given
+    ble a1, t0, 1f # return 1 if no file given
+    mv s0, a1 # store argc
+    li s1, 1 # i=1 (skip program name)
 
-    li a0, 1
 
+    3:
+    mv a0, s1
     call fetch_argv
-    beqz a0, 2f
+    bnez a0, 1f # error if failed
+    mv a0, a1
+    call cat_file
+    bnez a0, 1f # error if failed
+    addi s1, s1, 1
+    blt s1, s0, 3b
+    j 2f
 
     1:
     li a0, 1
@@ -26,10 +35,6 @@ _start:
     ecall # return 1
 
     2:
-    mv a0, a1
-    call cat_file
-    bnez a0, 1b # error if failed
-
     li a0, 0
     li a7, 93
     ecall   # return 0