Avoid failing fuse check if different bits are masked

Author: facchinm

Diff for: avrdude-6.3-patches/80-Avoid-failing-fuse-check-if-different-bits-are-reserved.patch

@@ -0,0 +1,88 @@
+--- avr.c
++++ avr.c
+@@ -1058,6 +1058,36 @@ int avr_signature(PROGRAMMER * pgm, AVRPART * p)
+   return 0;
+ }
+ 
++uint8_t get_fuse_bitmask(AVRMEM * m) {
++  uint8_t bitmask_r = 0;
++  uint8_t bitmask_w = 0;
++  int i, j;
++
++  if (m->size > 1) {
++    // not a fuse, compare bytes directly
++    return 0xFF;
++  }
++
++  for (i=0; i<AVR_OP_MAX; i++) {
++    if (m->op[i] && i == AVR_OP_READ) {
++      for (j=7; j>=0; j--) {
++        bitmask_r |= (m->op[i]->bit[j].type != AVR_CMDBIT_IGNORE) << j;
++      }
++    }
++    if (m->op[i] && i == AVR_OP_WRITE) {
++      for (j=7; j>=0; j--) {
++        bitmask_w |= (m->op[i]->bit[j].type != AVR_CMDBIT_VALUE  &&
++          m->op[i]->bit[j].type != AVR_CMDBIT_IGNORE) << j;
++      }
++    }
++  }
++  return bitmask_r & bitmask_w;
++}
++
++int compare_memory_masked(AVRMEM * m, unsigned char buf1, unsigned char buf2) {
++  uint8_t bitmask = get_fuse_bitmask(m);
++  return ((buf1 & bitmask) != (buf2 & bitmask));
++}
+ 
+ /*
+  * Verify the memory buffer of p with that of v.  The byte range of v,
+@@ -1103,7 +1133,7 @@ int avr_verify(AVRPART * p, AVRPART * v, char * memtype, int size)
+ 
+   for (i=0; i<size; i++) {
+     if ((b->tags[i] & TAG_ALLOCATED) != 0 &&
+-        buf1[i] != buf2[i]) {
++        compare_memory_masked(a , buf1[i], buf2[i])) {
+       avrdude_message(MSG_INFO, "%s: verification error, first mismatch at byte 0x%04x\n"
+                       "%s0x%02x != 0x%02x\n",
+                       progname, i,
+--- libavrdude.h
++++ libavrdude.h
+@@ -337,6 +337,9 @@ typedef void (*walk_avrparts_cb)(const char *name, const char *desc,
+                                  void *cookie);
+ void walk_avrparts(LISTID avrparts, walk_avrparts_cb cb, void *cookie);
+ void sort_avrparts(LISTID avrparts);
++
++uint8_t get_fuse_bitmask(AVRMEM * m);
++
+ #ifdef __cplusplus
+ }
+ #endif
+--- main.c
++++ main.c
+@@ -1239,6 +1239,7 @@ int main(int argc, char * argv [])
+     unsigned char safemodeafter_lfuse = 0xff;
+     unsigned char safemodeafter_hfuse = 0xff;
+     unsigned char safemodeafter_efuse = 0xff;
++    unsigned char safemodeafter_efuse_mask = 0xff;
+     unsigned char safemodeafter_fuse  = 0xff;
+     unsigned char failures = 0;
+     char yes[1] = {'y'};
+@@ -1345,8 +1346,15 @@ int main(int argc, char * argv [])
+       }
+     }
+ 
++    /* Get efuse bitmask if it exists */
++    AVRMEM * m;
++    m = avr_locate_mem(p, "efuse");
++    if (m != NULL) {
++      safemodeafter_efuse_mask = get_fuse_bitmask(m);
++    }
++
+     /* Now check what fuses are against what they should be */
+-    if (safemodeafter_efuse != safemode_efuse) {
++    if ((safemodeafter_efuse & safemodeafter_efuse_mask) != (safemode_efuse & safemodeafter_efuse_mask)) {
+       fuses_updated = 1;
+       avrdude_message(MSG_INFO, "%s: safemode: efuse changed! Was %x, and is now %x\n",
+               progname, safemode_efuse, safemodeafter_efuse);
+