Factor out string token search

kernel/config.asm

@@ -8,37 +8,6 @@ config_tokens:
 .none:
   db 0
 
-; IN	SI	offset of needle
-;	DI	offset to haystack table
-; OUT	DI	found offset in table
-;	ZF	zero flag set if match
-config_search_token:
-  push bp
-  push cx
-.loop:
-  cmp BYTE [di], 0
-  je .fail
-  push si
-  push di
-  mov bp, di
-  xor ch, ch
-  mov cl, [di]
-  inc di
-  add bp, cx
-  inc bp
-  repe cmpsb
-  pop di
-  pop si
-  je .end
-  mov di, bp
-  jmp .loop
-.fail:
-  stc
-.end:
-  pop cx
-  pop cx
-  ret
-
 config_parse_int:
   ret
 
@@ -46,6 +15,6 @@ config_parse_int:
 config_first_run:
   mov si, bx
   mov di, config_tokens
-  call config_search_token
+  call string_search_token
   int3
   ret

kernel/main.asm

@@ -58,6 +58,7 @@ init:
   hlt
   jmp .halt
 
+%include "string.asm"
 %include "config.asm"
 
 kernel_end:

kernel/string.asm

@@ -0,0 +1,31 @@
+; IN    DS:SI   offset of needle
+;       ES:DI   offset to haystack table
+; OUT   ES:DI   found offset in table
+;       ZF      zero flag set if match
+
+string_search_token:
+  push bp
+  push cx
+.loop:
+  cmp BYTE [es:di], 0
+  je .fail
+  push si
+  push di
+  mov bp, di
+  xor ch, ch
+  mov cl, [es:di]
+  inc di
+  add bp, cx
+  inc bp
+  repe cmpsb
+  pop di
+  pop si
+  je .end
+  mov di, bp
+  jmp .loop
+.fail:
+  stc
+.end:
+  pop cx
+  pop cx
+  ret