avrdude/patches/: added skipping of untouched bytes in write/verify

- series, low-addr.patch: record the lowest address touched (only for
  ihex, all others default to 0)
- series, skip-low-addr.patch: skip untouched addresses in avr_read
  and avr_write

avrdude/patches/low-addr.patch

@@ -0,0 +1,142 @@
+Index: avrdude/avrdude-5.10/avrpart.h
+===================================================================
+--- avrdude.orig/avrdude-5.10/avrpart.h	2011-03-08 23:40:10.000000000 -0300
++++ avrdude/avrdude-5.10/avrpart.h	2011-03-08 23:40:13.000000000 -0300
+@@ -185,6 +185,8 @@
+ 
+   unsigned char * buf;        /* pointer to memory buffer */
+   OPCODE * op[AVR_OP_MAX];    /* opcodes */
++
++  int low_addr;		      /* lowest address used, in bytes */
+ } AVRMEM;
+ 
+ #ifdef __cplusplus
+Index: avrdude/avrdude-5.10/config_gram.y
+===================================================================
+--- avrdude.orig/avrdude-5.10/config_gram.y	2011-03-08 23:40:10.000000000 -0300
++++ avrdude/avrdude-5.10/config_gram.y	2011-03-08 23:40:13.000000000 -0300
+@@ -1209,6 +1209,7 @@
+     } 
+     mem_specs 
+     { 
++      current_mem->low_addr = current_mem->size;
+       ladd(current_part->mem, current_mem); 
+       current_mem = NULL; 
+     } |
+Index: avrdude/avrdude-5.10/fileio.c
+===================================================================
+--- avrdude.orig/avrdude-5.10/fileio.c	2011-03-08 23:40:10.000000000 -0300
++++ avrdude/avrdude-5.10/fileio.c	2011-03-08 23:40:13.000000000 -0300
+@@ -52,7 +52,7 @@
+              char * outfile, FILE * outf);
+ 
+ static int ihex2b(char * infile, FILE * inf,
+-             unsigned char * outbuf, int bufsize);
++             unsigned char * outbuf, int bufsize, int *low_addr);
+ 
+ static int b2srec(unsigned char * inbuf, int bufsize, 
+            int recsize, int startaddr,
+@@ -69,7 +69,8 @@
+                   char * filename, FILE * f, unsigned char * buf, int size);
+ 
+ static int fileio_ihex(struct fioparms * fio, 
+-                  char * filename, FILE * f, unsigned char * buf, int size);
++                  char * filename, FILE * f, unsigned char * buf, int size,
++		  int *low_addr);
+ 
+ static int fileio_srec(struct fioparms * fio,
+                   char * filename, FILE * f, unsigned char * buf, int size);
+@@ -262,7 +263,7 @@
+  *
+  * */
+ static int ihex2b(char * infile, FILE * inf,
+-             unsigned char * outbuf, int bufsize)
++             unsigned char * outbuf, int bufsize, int *low_addr)
+ {
+   char buffer [ MAX_LINE_LEN ];
+   unsigned char * buf;
+@@ -271,7 +272,7 @@
+   int lineno;
+   int len;
+   struct ihexrec ihex;
+-  int rc;
++  int rc, lowest;
+ 
+   lineno      = 0;
+   buf         = outbuf;
+@@ -279,6 +280,7 @@
+   maxaddr     = 0;
+   offsetaddr  = 0;
+   nextaddr    = 0;
++  lowest      = bufsize;
+ 
+   while (fgets((char *)buffer,MAX_LINE_LEN,inf)!=NULL) {
+     lineno++;
+@@ -313,11 +315,14 @@
+         for (i=0; i<ihex.reclen; i++) {
+           buf[nextaddr+i-offsetaddr] = ihex.data[i];
+         }
++	if (nextaddr-offsetaddr < lowest)
++	  lowest = nextaddr-offsetaddr;
+         if (nextaddr+ihex.reclen > maxaddr)
+           maxaddr = nextaddr+ihex.reclen;
+         break;
+ 
+       case 1: /* end of file record */
++	*low_addr = lowest;
+         return maxaddr-offsetaddr;
+         break;
+ 
+@@ -354,6 +359,7 @@
+           "file \"%s\"\n",
+           progname, infile);
+ 
++  *low_addr = lowest;
+   return maxaddr-offsetaddr;
+ }
+ 
+@@ -777,7 +783,8 @@
+ 
+ 
+ static int fileio_ihex(struct fioparms * fio, 
+-                  char * filename, FILE * f, unsigned char * buf, int size)
++                  char * filename, FILE * f, unsigned char * buf, int size,
++		  int *low_addr)
+ {
+   int rc;
+ 
+@@ -790,7 +797,7 @@
+       break;
+ 
+     case FIO_READ:
+-      rc = ihex2b(filename, f, buf, size);
++      rc = ihex2b(filename, f, buf, size, low_addr);
+       if (rc < 0)
+         return -1;
+       break;
+@@ -1021,6 +1028,7 @@
+   struct fioparms fio;
+   AVRMEM * mem;
+   int using_stdio;
++  int low_addr = 0;
+ 
+   mem = avr_locate_mem(p, memtype);
+   if (mem == NULL) {
+@@ -1113,7 +1121,7 @@
+ 
+   switch (format) {
+     case FMT_IHEX:
+-      rc = fileio_ihex(&fio, fname, f, buf, size);
++      rc = fileio_ihex(&fio, fname, f, buf, size, &low_addr);
+       break;
+ 
+     case FMT_SREC:
+@@ -1149,6 +1157,8 @@
+        */
+       rc = avr_mem_hiaddr(mem);
+     }
++    if (op == FIO_READ && low_addr < mem->low_addr)
++	mem->low_addr = low_addr;
+   }
+   if (format != FMT_IMM && !using_stdio) {
+     fclose(f);