Merge branch 'main' into issue_1832

NEWS

@@ -43,6 +43,7 @@ Changes since version 7.3:
     - ATtiny11 does not have EEPROM #1812
     - AVRDUDE fails to return -1 on some write errors #1821
     - Multi-memory files #1817
+    - Terminal erase command #1833
 
   * Pull requests:
 
@@ -100,6 +101,8 @@ Changes since version 7.3:
     - Downgrade out-of-range file input errors on -F #1818
     - Multi-memory file handling #1828
     - Add developer options -p*/vcr to explore SW compatibility #1830
+    - Improve chip erase emulation for dryboot/dryrun #1836
+    - Use page erase for UPDI programming #1837
 
   * Internals:
 

src/avrcache.c

@@ -66,8 +66,8 @@
  * flash (and sometimes EEPROM, too) looks like a NOR memory, ie, a write can
  * only clear bits, never set them. For NOR memories a page erase or, if not
  * available, a chip erase needs to be issued before writing arbitrary data.
- * Bootrow and usersig are generally unaffected by a chip erase, so will need
- * a page erase. When a memory looks like a NOR memory, either page erase is
+ * Usersig is generally unaffected by a chip erase, so will always need a
+ * page erase. When a memory looks like a NOR memory, either page erase is
  * deployed (eg, with parts that have PDI/UPDI interfaces), or if that is not
  * available, both EEPROM and flash caches are fully read in, a
  * pgm->chip_erase() command is issued and both EEPROM and flash are written
@@ -90,7 +90,7 @@
  * has these clear bits on the device. Only with this evidence is the EEPROM
  * cache preset to all 0xff otherwise the cache discards all pending writes
  * to EEPROM and is left unchanged otherwise. avr_chip_erase_cached() does not
- * affect the bootrow or usersig cache.
+ * affect the usersig cache.
  *
  * The avr_page_erase_cached() function erases a page and synchronises it
  * with the cache.
@@ -689,10 +689,11 @@ int avr_write_byte_cached(const PROGRAMMER *pgm, const AVRPART *p, const AVRMEM
 
 // Erase the chip and set the cache accordingly
 int avr_chip_erase_cached(const PROGRAMMER *pgm, const AVRPART *p) {
-  Cache_desc mems[3] = {
+  Cache_desc mems[] = {
     { avr_locate_flash(p), pgm->cp_flash, 1, 0, -1, 0 },
     { avr_locate_eeprom(p), pgm->cp_eeprom, 0, 1, -1, 0 },
-    // bootrow/usersig is unaffected by CE
+    { avr_locate_bootrow(p), pgm->cp_bootrow, 0, 0, -1, 0 },
+    // usersig is unaffected by CE
   };
   int rc;
 
@@ -718,19 +719,19 @@ int avr_chip_erase_cached(const PROGRAMMER *pgm, const AVRPART *p) {
         memset(cp->cont, 0xff, cp->size);
         memset(cp->iscached, 1, cp->size/cp->page_size);
       }
-    } else if(mems[i].iseeprom) { // Test whether cached EEPROM pages were zapped
-      bool erasedee = 0;
+    } else {                    // Test whether cached EEPROM/bootrow pages were zapped
+      bool erased = 0;
       for(int pgno = 0, n = 0; n < cp->size; pgno++, n += cp->page_size) {
         if(cp->iscached[pgno]) {
-          if(!is_memset(cp->copy + n, 0xff, cp->page_size)) { // Page has EEPROM data?
+          if(!is_memset(cp->copy + n, 0xff, cp->page_size)) { // Page has data?
             if(avr_read_page_default(pgm, p, mem, n, cp->copy + n) < 0)
               return LIBAVRDUDE_GENERAL_FAILURE;
-            erasedee = is_memset(cp->copy + n, 0xff, cp->page_size);
+            erased = is_memset(cp->copy + n, 0xff, cp->page_size);
             break;
           }
         }
       }
-      if(erasedee) {            // EEPROM was erased, set cache correspondingly
+      if(erased) {              // Memory was erased, set cache correspondingly
         memset(cp->copy, 0xff, cp->size);
         memset(cp->cont, 0xff, cp->size);
         memset(cp->iscached, 1, cp->size/cp->page_size);

src/avrdude.1

@@ -472,17 +472,15 @@ arduino.
 .It Fl D
 Disable auto erase for flash.  When the
 .Fl U
-option with flash memory is specified,
+option for writing to any flash memory is specified,
 .Nm
 will perform a chip erase before starting any of the programming
-operations, since it generally is a mistake to program the flash
-without performing an erase first.  This option disables that.
-Auto erase is not used for ATxmega devices as these devices can
-use page erase before writing each page so no explicit chip erase
-is required.
-Note however that any page not affected by the current operation
-will retain its previous contents.
-Setting
+operations, since it generally is a mistake to program the flash without
+performing an erase first.  This option disables that. Auto erase is not
+used for ATxmega parts nor for the UPDI (AVR8X family) parts as these can
+use page erase before writing each page so no explicit chip erase is
+required. Note, however, that any flash page not affected by the current
+operation will retain its previous contents. Setting
 .Fl D
 implies
 .Fl A.
@@ -491,9 +489,9 @@ Causes a chip erase to be executed.  This will reset the contents of the
 flash ROM and EEPROM to the value
 .Ql 0xff ,
 and clear all lock bits.
-Except for ATxmega devices which can use page erase,
-it is basically a prerequisite command before the flash ROM can be
-reprogrammed again.  The only exception would be if the new
+Except for ATxmega and UPDI (AVR8X family) devices, all of which can use
+page erase, it is basically a prerequisite command before the flash ROM
+can be reprogrammed again.  The only exception would be if the new
 contents would exclusively cause bits to be programmed from the value
 .Ql 1
 to
@@ -797,6 +795,7 @@ The available memory types are device-dependent, the actual configuration
 can be viewed with the
 .Cm part
 command in terminal mode.
+.Pp
 Typically, a device's memory configuration at least contains
 the memories
 .Ar flash ,
@@ -812,10 +811,26 @@ memory contains the three device signature bytes, which should
 be, but not always are, unique for the part. The
 .Ar lock
 memory of one or four bytes typically details whether or not external
-reading/writing of the flash memory, or parts of it, is allowed. Parts
-will also typically have fuse bytes, which are read/write memories for
-configuration of the device and calibration memories that typically
-contain read-only factory calibration values.
+reading/writing of the flash memory, or parts of it, is allowed. After
+restricting access via the lock memory, often the only way to unlock
+memory is via a chip erase. Parts will also typically have fuse bytes,
+which are read/write memories for configuration of the device and
+calibration memories that typically contain read-only factory calibration
+values.
+.Pp
+The flash memory, being physically implemented as NOR-memory, is special
+in the sense that it is normally only possible to program bits to change
+from 1 to 0. Before reprogramming takes place normally flash memory has
+to be erased. Older parts would only offer a chip erase to do so, which
+also erases EEPROM unless a fuse configuration preserves its contents. If
+AVRDUDE detects a -U option that writes to a flash memory it will
+automatically trigger a chip erase for these older parts.  ATxmegas or
+UPDI parts (AVR8X family) offer a page erase, and AVRDUDE takes advantage
+of that by erasing pages before programming them unless -e (chip erase) or
+-D (do not erase before writing) was requested. It should be noted that in
+absence of the -e chip erase option any ATxmega or UPDI flash pages not
+affected by the programming will retain their previous content.
+
 .Pp
 Classic devices may have the following memories in addition to eeprom, flash, signature and lock:
 .Bl -tag -width "  calibration" -compact
@@ -937,10 +952,11 @@ Temperature sensor calibration values
 .It bootrow
 Extra page of memory that is only accessible by the MCU in bootloader
 code; UDPI can read and write this memory only when the device is
-unlocked; bootrow is not erased during chip erase
+unlocked
 .It userrow
 Extra page of EEPROM memory that can be used for firmware settings; this
-memory is not erased during a chip erase
+memory is not erased during a chip erase; UPDI cannot read this memory
+when the device is locked
 .It sib
 Special system information block memory with information about AVR family, chip revision etc.
 .It io
@@ -1263,8 +1279,9 @@ command line argument.
 .Ar verify
 flushes the cache before verifying memories.
 .It Ar erase
-Perform a chip erase and discard all pending writes to EEPROM and flash.
-Note that EEPROM will be preserved if the EESAVE fuse bit is set.
+Perform a chip erase and discard all pending writes to flash, EEPROM and bootrow.
+Note that EEPROM will be preserved if the EESAVE fuse bit is active, ie, had
+a corresponding value at the last reset prior to the operation.
 .It Ar erase memory
 Erase the entire specified memory.
 .It Ar erase memory addr len
@@ -1274,8 +1291,8 @@ Synchronise with the device all pending writes to flash, EEPROM, bootrow and
 usersig. With some programmer and part combinations, flash (and sometimes
 EEPROM, too) looks like a NOR memory, i.e., a write can only clear bits,
 never set them. For NOR memories a page erase or, if not available, a chip
-erase needs to be issued before writing arbitrary data. Bootrow and usersig are
-generally unaffected by a chip erase. When a memory looks like a NOR
+erase needs to be issued before writing arbitrary data. Usersig is
+unaffected by a chip erase. When a memory looks like a NOR
 memory, either page erase is deployed (e.g., with parts that have PDI/UPDI
 interfaces), or if that is not available, both EEPROM and flash caches are
 fully read in, a chip erase command is issued and both EEPROM and flash

src/doc/avrdude.texi

@@ -584,31 +584,28 @@ engaged by default when specifying -c arduino.
 
 @item -D
 @cindex Option @code{-D}
-Disable auto erase for flash.  When the -U option with flash memory is 
-specified, avrdude will perform a chip erase before starting any of the 
-programming operations, since it generally is a mistake to program the flash
-without performing an erase first.  This option disables that.
-Auto erase is not used for ATxmega devices as these devices can
-use page erase before writing each page so no explicit chip erase
-is required.
-Note however that any page not affected by the current operation
-will retain its previous contents.
-Setting -D implies -A.
+Disable auto erase for flash.  When the -U  option for writing to any
+flash memory is specified, AVRDUDE will perform a chip erase before
+starting any of the  programming  operations, since it generally is a
+mistake to program the flash without performing an erase first.  This
+option disables that. Auto erase is not used for ATxmega parts nor for the
+UPDI (AVR8X family) parts as these can use page erase before writing each
+page so no explicit chip erase is required. Note, however, that any flash
+page not affected by the current operation will retain its previous
+contents. Setting -D implies -A.
 
 @item -e
 @cindex Option @code{-e}
 Causes a chip erase to be executed.  This will reset the contents of the
-flash and EEPROM to the value `0xff', and clear all lock bits.
-Except for ATxmega devices which can use page erase,
-it is basically a
-prerequisite command before the flash can be reprogrammed again.
-The only exception would be if the new contents would exclusively cause
-bits to be programmed from the value `1' to `0'.  Note that in order
-to reprogram EERPOM cells, no explicit prior chip erase is required
-since the MCU provides an auto-erase cycle in that case before
+flash and EEPROM to the value `0xff', and clear all lock bits. Except for
+ATxmega and UPDI (AVR8X family) devices, all of which can use page erase,
+it is basically a prerequisite command before the flash ROM can be
+reprogrammed again.  The only exception would be if the new contents would
+exclusively cause bits to be programmed from the value `1' to `0'. Note
+that in order to reprogram EERPOM cells, no explicit prior chip erase is
+required since the MCU provides an auto-erase cycle in that case before
 programming the cell.
 
-
 @item -E @var{exitspec}[,@dots{}]
 @cindex Option @code{-E} @var{exitspec}[,@dots{}]
 By default, AVRDUDE leaves the parallel port in the same state at exit
@@ -860,9 +857,24 @@ is sometimes known as @code{lockbits}. The signature memory contains the
 three device signature bytes, which should be, but not always are, unique
 for the part. The @code{lock} memory of one or four bytes typically
 details whether or not external reading/writing of the flash memory, or
-parts of it, is allowed. Parts will also typically have fuse bytes, which
-are read/write memories for configuration of the device and calibration
-memories that typically contain read-only factory calibration values.
+parts of it, is allowed. After restricting access via the lock memory,
+often the only way to unlock memory is via a chip erase.  Parts will also
+typically have fuse bytes, which are read/write memories for configuration
+of the device and calibration memories that typically contain read-only
+factory calibration values.
+
+The flash memory, being physically implemented as NOR-memory, is special
+in the sense that it is normally only possible to program bits to change
+from 1 to 0. Before reprogramming takes place normally flash memory has to
+be erased. Older parts would only offer a chip erase to do so, which also
+erases EEPROM unless a fuse configuration preserves its contents. If
+AVRDUDE detects a -U option that writes to a flash memory it will
+automatically trigger a chip erase for these older parts.  ATxmegas or
+UPDI parts (AVR8X family) offer a page erase, and AVRDUDE takes advantage
+of that by erasing pages before programming them unless -e (chip erase) or
+-D (do not erase before writing) was requested. It should be noted that in
+absence of the -e chip erase option any ATxmega or UPDI flash pages not
+affected by the programming will retain their previous content.
 
 Classic devices may have the following memories in addition to
 @code{eeprom}, @code{flash}, @code{signature} and @code{lock}:
@@ -981,7 +993,7 @@ Temperature sensor calibration values
 @item bootrow
 Extra page of memory that is only accessible by the MCU in bootloader
 code; UDPI can read and write this memory only when the device is
-unlocked; bootrow is not erased during chip erase
+unlocked
 @item userrow
 Extra page of EEPROM memory that can be used for firmware settings; this
 memory is not erased during a chip erase
@@ -2509,8 +2521,9 @@ comma separated list of memories just as in the @code{-U} command line
 argument. @code{verify} flushes the cache before verifying memories.
 
 @item erase
-Perform a chip erase and discard all pending writes to EEPROM and flash.
-Note that EEPROM will be preserved if the EESAVE fuse bit is set.
+Perform a chip erase and discard all pending writes to flash, EEPROM and bootrow.
+Note that EEPROM will be preserved if the EESAVE fuse bit is active, ie, had
+a corresponding value at the last reset prior to the operation.
 
 @item erase @var{memory}
 Erase the entire specified memory.
@@ -2523,8 +2536,8 @@ Synchronise with the device all pending writes to flash, EEPROM, bootrow and
 usersig. With some programmer and part combinations, flash (and sometimes
 EEPROM, too) looks like a NOR memory, i.e., a write can only clear bits,
 never set them. For NOR memories a page erase or, if not available, a chip
-erase needs to be issued before writing arbitrary data. Bootrow and usersig are
-generally unaffected by a chip erase. When a memory looks like a NOR
+erase needs to be issued before writing arbitrary data. Usersig is
+unaffected by a chip erase. When a memory looks like a NOR
 memory, either page erase is deployed (e.g., with parts that have PDI/UPDI
 interfaces), or if that is not available, both EEPROM and flash caches are
 fully read in, a chip erase command is issued and both EEPROM and flash