rockbox: move firmware checksum algorithms into a common header

Before this was just implemented inline wherever it was needed. Now
it is provided as 2 inline functions in a header called checksum.h.
There should be no differences in actual behavior.

Change-Id: I5d756cc01dc6225f5cc8b6af90911a3fc7b57cd5

2 files changed, 3 insertions, 20 deletions

diff --git a/apps/plugins/crypt_firmware.c b/apps/plugins/crypt_firmware.c
index f9bdd4d031..14e9c2be96 100644
--- a/apps/plugins/crypt_firmware.c
+++ b/apps/plugins/crypt_firmware.c
@@ -36,8 +36,7 @@
 */
 
 #include "plugin.h"
-
-
+#include "checksum.h"
 
 static void aes_encrypt(void* data, uint32_t size)
 {
@@ -133,17 +132,6 @@ static void put_uint32be(unsigned char* buf, uint32_t x)
     buf[3] = x & 0xff;
 }
 
-static uint32_t calc_checksum(uint32_t sum, unsigned char* buf, int len)
-{
-   int i;
-
-   for (i = 0; i < len ; i++) {
-      sum += buf[i];
-   }
-
-   return sum;
-}
-
 enum plugin_status plugin_start(const void* parameter)
 {
     int fd;
diff --git a/apps/plugins/iriver_flash.c b/apps/plugins/iriver_flash.c
index 9454ac63c8..152ac339ff 100644
--- a/apps/plugins/iriver_flash.c
+++ b/apps/plugins/iriver_flash.c
@@ -23,6 +23,7 @@
  ****************************************************************************/
 #include "plugin.h"
 #include "lib/helper.h"
+#include "checksum.h"
 
 /*
  * Flash commands may rely on null pointer dereferences to work correctly.
@@ -395,7 +396,6 @@ static bool load_firmware(const char* filename, enum firmware firmware,
     {
         uint32_t checksum;
         uint8_t model[4];
-        uint32_t sum;
 
         /* subtract the header length */
         fd_len -= sizeof(checksum) + sizeof(model);
@@ -418,13 +418,8 @@ static bool load_firmware(const char* filename, enum firmware firmware,
             goto bail;
         }
 
-        /* calculate the checksum */
-        sum = MODEL_NUMBER;
-        for (off_t i = 0; i < fd_len; i++)
-            sum += buffer[i];
-
         /* verify the checksum */
-        if (sum != checksum)
+        if (!verify_checksum(checksum, buffer, fd_len))
         {
             msg = "Aborting: checksum mismatch";
             goto bail;