From b49a49f31c0aefcacd609f1554e0c3368f1c1fbf Mon Sep 17 00:00:00 2001
From: schneider <schneider@blinkenlichts.net>
Date: Tue, 19 Jul 2011 01:21:05 +0200
Subject: [PATCH] filesystem: add option to decode loadables

---
 firmware/basic/xxtea.c        |  3 ++-
 firmware/basic/xxtea.h        |  3 ++-
 firmware/filesystem/execute.c | 17 ++++++++++++++---
 firmware/filesystem/execute.h |  2 +-
 4 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/firmware/basic/xxtea.c b/firmware/basic/xxtea.c
index 91e0316..9ae81f8 100644
--- a/firmware/basic/xxtea.c
+++ b/firmware/basic/xxtea.c
@@ -37,7 +37,8 @@ void htonlp(uint32_t *v, uint8_t n)
     }
 }
 
-void xxtea_cbcmac(uint32_t mac[4], uint32_t *data, uint32_t len, uint32_t key[4])
+void xxtea_cbcmac(uint32_t mac[4], uint32_t *data,
+                    uint32_t len, uint32_t const key[4])
 {
     if( len & 0x03 )
         return;
diff --git a/firmware/basic/xxtea.h b/firmware/basic/xxtea.h
index 4a08ce6..da93394 100644
--- a/firmware/basic/xxtea.h
+++ b/firmware/basic/xxtea.h
@@ -1,7 +1,8 @@
 #ifndef _XXTEA_H_
 #define _XXTEA_H_
 
-void xxtea_cbcmac(uint32_t mac[4], uint32_t *data, uint32_t len, uint32_t key[4]);
+void xxtea_cbcmac(uint32_t mac[4], uint32_t *data,
+        uint32_t len, uint32_t const key[4]);
 void xxtea_encode_words(uint32_t *v, int n, uint32_t const k[4]);
 void xxtea_decode_words(uint32_t *v, int n, uint32_t const k[4]);
 
diff --git a/firmware/filesystem/execute.c b/firmware/filesystem/execute.c
index 071b910..ee387b0 100644
--- a/firmware/filesystem/execute.c
+++ b/firmware/filesystem/execute.c
@@ -10,14 +10,16 @@
 #include "filesystem/ff.h"
 #include "filesystem/select.h"
 
+#include "basic/xxtea.h"
 
 const uint32_t signature_key[4] = {0,0,0,0};
+const uint32_t decode_key[4] = {0,0,0,0};
 
 extern void * sram_top;
 
 /**************************************************************************/
 
-void execute_file (const char * fname, uint8_t checksignature){
+void execute_file (const char * fname, uint8_t checksignature, uint8_t decode){
     FRESULT res;
     FIL file;
     UINT readbytes;
@@ -45,18 +47,27 @@ void execute_file (const char * fname, uint8_t checksignature){
     if(res){
         return;
     };
+
+    if( decode || checksignature )
+        if( readbytes & 0x03 )
+            return;
     
     if( checksignature ){
         uint32_t mac[4];
         uint32_t *data = (uint32_t*)dst;
         uint32_t len = readbytes/4;
-
         xxtea_cbcmac(mac, (uint32_t*)dst, len-4, signature_key);
         if( data[len-4] != mac[0] || data[len-3] != mac[1]
             || data[len-2] != mac[2] || data[len-1] != mac[3] ){
             return;
         }
     }
+
+    if( decode ){
+        uint32_t *data = (uint32_t*)dst;
+        uint32_t len = readbytes/4;
+        xxtea_decode_words(data, len, decode_key);
+    }
     //lcdPrintInt(readbytes);
     //lcdPrintln(" bytes");
     //lcdRefresh();
@@ -75,6 +86,6 @@ void executeSelect(char *ext){
     filename[2]=0;
 
     if( selectFile(filename+2,ext) == 0)
-        execute_file(filename,0);
+        execute_file(filename,0,0);
 };
 
diff --git a/firmware/filesystem/execute.h b/firmware/filesystem/execute.h
index 2b4b0f1..8c52cae 100644
--- a/firmware/filesystem/execute.h
+++ b/firmware/filesystem/execute.h
@@ -1,7 +1,7 @@
 #ifndef _EXECUTE_H_
 #define _EXECUTE_H_
 
-void execute_file (const char * fname, uint8_t checksignature);
+void execute_file (const char * fname, uint8_t checksignature, uint8_t decode);
 void executeSelect(char *ext);
 
 #endif