From 9a97e1c7c566c23c6c54a468e5267a0595f0abc7 Mon Sep 17 00:00:00 2001
From: Christian Pointner <equinox@spreadspace.org>
Date: Thu, 4 Jul 2013 23:39:02 +0000
Subject: added check for invalid command codes

git-svn-id: https://svn.spreadspace.org/pic/trunk@38 a09c6847-51d9-44de-8ef2-e725cf50f3c7
---
 bootloader/bootloader.asm | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/bootloader/bootloader.asm b/bootloader/bootloader.asm
index bbf88b8..3ff8aa4 100644
--- a/bootloader/bootloader.asm
+++ b/bootloader/bootloader.asm
@@ -29,7 +29,7 @@
 
   ;; -------------------------------------
   ;; DEFINES
-#define         BOOTPIN   PORTC,7
+#define BOOTPIN           PORTC,7
 USERVECT        EQU       H'100'
 ISRVECT         EQU       USERVECT + H'4'
 
@@ -76,7 +76,8 @@ current_cmdlen  EQU       H'0070'
 csum            EQU       H'0071'
 
 flags           EQU       H'007D'
-weep            EQU       .0
+#define F_INVALID_CMD     flags,0
+#define F_WEEP            flags,7
 
 cnt2            EQU       H'007E'
 cnt1            EQU       H'007F'
@@ -120,7 +121,11 @@ send_answer_next
   return
 
 check_cmd_code
-  retlw     CMD_INVALID
+  movf      combuff,w
+  sublw     CMD_MAX
+  btfss     STATUS,C
+  bsf       F_INVALID_CMD
+  return
 
 get_cmdlen
   addwf     PCL,f
@@ -197,7 +202,7 @@ uart_rx_oe                      ; recover from overflow
 uart_rx_byte                    ; process received command
   btfsc     RCSTA,FERR
   goto      uart_rx_fe
-  movf      RCREG,w             ; TODO: check parity??
+  movf      RCREG,w
   movwf     INDF
   incf      FSR,f
   movf      current_cmdlen,f
@@ -213,9 +218,9 @@ uart_rx_fe                      ; recover from framing error
 
 new_cmd                         ; got new command code
   call      check_cmd_code
-  movf      combuff,w
-  btfsc     STATUS,Z
+  btfsc     F_INVALID_CMD
   goto      invalid_cmd
+  movf      combuff,w
   call      get_cmdlen
   movwf     current_cmdlen
   goto      wait_cmd
@@ -338,7 +343,7 @@ cmd_r_eeprom
 
   ;; ** write eeprom *******
 cmd_w_eeprom
-  btfss     flags,weep
+  btfss     F_WEEP
   goto      cmd_w_eeprom_len
   ;; call      write_eeprom
   movlw     E_ADDR_INVALID
@@ -350,7 +355,7 @@ cmd_w_eeprom
 cmd_w_eeprom_len
   movf      combuff + .3,w
   movwf     current_cmdlen
-  bsf       flags,weep
+  bsf       F_WEEP
   goto      wait_cmd
 
   ;; ** not implemented commands *******
-- 
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