boot.h
  1  /* Modified to use out for SPM access
  2  ** Peter Knight, Optiboot project http://optiboot.googlecode.com
  3  **
  4  ** Todo: Tidy up
  5  **
  6  ** "_short" routines execute 1 cycle faster and use 1 less word of flash
  7  ** by using "out" instruction instead of "sts".
  8  **
  9  ** Additional elpm variants that trust the value of RAMPZ
 10  */
 11  
 12  /* Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007  Eric B. Weddington
 13     All rights reserved.
 14  
 15     Redistribution and use in source and binary forms, with or without
 16     modification, are permitted provided that the following conditions are met:
 17  
 18     * Redistributions of source code must retain the above copyright
 19       notice, this list of conditions and the following disclaimer.
 20     * Redistributions in binary form must reproduce the above copyright
 21       notice, this list of conditions and the following disclaimer in
 22       the documentation and/or other materials provided with the
 23       distribution.
 24     * Neither the name of the copyright holders nor the names of
 25       contributors may be used to endorse or promote products derived
 26       from this software without specific prior written permission.
 27  
 28    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 29    AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 30    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 31    ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 32    LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 33    CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 34    SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 35    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 36    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 37    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 38    POSSIBILITY OF SUCH DAMAGE. */
 39  
 40  /* $Id: boot.h,v 1.27.2.3 2008/09/30 13:58:48 arcanum Exp $ */
 41  
 42  #ifndef _AVR_BOOT_H_
 43  #define _AVR_BOOT_H_    1
 44  
 45  /** \file */
 46  /** \defgroup avr_boot <avr/boot.h>: Bootloader Support Utilities
 47      \code
 48      #include <avr/io.h>
 49      #include <avr/boot.h>
 50      \endcode
 51  
 52      The macros in this module provide a C language interface to the
 53      bootloader support functionality of certain AVR processors. These
 54      macros are designed to work with all sizes of flash memory.
 55  
 56      Global interrupts are not automatically disabled for these macros. It
 57      is left up to the programmer to do this. See the code example below. 
 58      Also see the processor datasheet for caveats on having global interrupts 
 59      enabled during writing of the Flash.
 60  
 61      \note Not all AVR processors provide bootloader support. See your
 62      processor datasheet to see if it provides bootloader support.
 63  
 64      \todo From email with Marek: On smaller devices (all except ATmega64/128),
 65      __SPM_REG is in the I/O space, accessible with the shorter "in" and "out"
 66      instructions - since the boot loader has a limited size, this could be an
 67      important optimization.
 68  
 69      \par API Usage Example
 70      The following code shows typical usage of the boot API.
 71  
 72      \code
 73      #include <inttypes.h>
 74      #include <avr/interrupt.h>
 75      #include <avr/pgmspace.h>
 76      
 77      void boot_program_page (uint32_t page, uint8_t *buf)
 78      {
 79          uint16_t i;
 80          uint8_t sreg;
 81  
 82          // Disable interrupts.
 83  
 84          sreg = SREG;
 85          cli();
 86      
 87          eeprom_busy_wait ();
 88  
 89          boot_page_erase (page);
 90          boot_spm_busy_wait ();      // Wait until the memory is erased.
 91  
 92          for (i=0; i<SPM_PAGESIZE; i+=2)
 93          {
 94              // Set up little-endian word.
 95  
 96              uint16_t w = *buf++;
 97              w += (*buf++) << 8;
 98          
 99              boot_page_fill (page + i, w);
100          }
101  
102          boot_page_write (page);     // Store buffer in flash page.
103          boot_spm_busy_wait();       // Wait until the memory is written.
104  
105          // Reenable RWW-section again. We need this if we want to jump back
106          // to the application after bootloading.
107  
108          boot_rww_enable ();
109  
110          // Re-enable interrupts (if they were ever enabled).
111  
112          SREG = sreg;
113      }\endcode */
114  
115  #include <avr/eeprom.h>
116  #include <avr/io.h>
117  #include <inttypes.h>
118  #include <limits.h>
119  
120  /* Check for SPM Control Register in processor. */
121  #if defined (SPMCSR)
122  #  define __SPM_REG    SPMCSR
123  #elif defined (SPMCR)
124  #  define __SPM_REG    SPMCR
125  #else
126  #  error AVR processor does not provide bootloader support!
127  #endif
128  
129  
130  /* Check for SPM Enable bit. */
131  #if defined(SPMEN)
132  #  define __SPM_ENABLE  SPMEN
133  #elif defined(SELFPRGEN)
134  #  define __SPM_ENABLE  SELFPRGEN
135  #else
136  #  error Cannot find SPM Enable bit definition!
137  #endif
138  
139  /** \ingroup avr_boot
140      \def BOOTLOADER_SECTION
141  
142      Used to declare a function or variable to be placed into a
143      new section called .bootloader. This section and its contents
144      can then be relocated to any address (such as the bootloader
145      NRWW area) at link-time. */
146  
147  #define BOOTLOADER_SECTION    __attribute__ ((section (".bootloader")))
148  
149  /* Create common bit definitions. */
150  #ifdef ASB
151  #define __COMMON_ASB    ASB
152  #else
153  #define __COMMON_ASB    RWWSB
154  #endif
155  
156  #ifdef ASRE
157  #define __COMMON_ASRE   ASRE
158  #else
159  #define __COMMON_ASRE   RWWSRE
160  #endif
161  
162  /* Define the bit positions of the Boot Lock Bits. */
163  
164  #define BLB12           5
165  #define BLB11           4
166  #define BLB02           3
167  #define BLB01           2
168  
169  /** \ingroup avr_boot
170      \def boot_spm_interrupt_enable()
171      Enable the SPM interrupt. */
172  
173  #define boot_spm_interrupt_enable()   (__SPM_REG |= (uint8_t)_BV(SPMIE))
174  
175  /** \ingroup avr_boot
176      \def boot_spm_interrupt_disable()
177      Disable the SPM interrupt. */
178  
179  #define boot_spm_interrupt_disable()  (__SPM_REG &= (uint8_t)~_BV(SPMIE))
180  
181  /** \ingroup avr_boot
182      \def boot_is_spm_interrupt()
183      Check if the SPM interrupt is enabled. */
184  
185  #define boot_is_spm_interrupt()       (__SPM_REG & (uint8_t)_BV(SPMIE))
186  
187  /** \ingroup avr_boot
188      \def boot_rww_busy()
189      Check if the RWW section is busy. */
190  
191  #define boot_rww_busy()          (__SPM_REG & (uint8_t)_BV(__COMMON_ASB))
192  
193  /** \ingroup avr_boot
194      \def boot_spm_busy()
195      Check if the SPM instruction is busy. */
196  
197  #define boot_spm_busy()               (__SPM_REG & (uint8_t)_BV(__SPM_ENABLE))
198  
199  /** \ingroup avr_boot
200      \def boot_spm_busy_wait()
201      Wait while the SPM instruction is busy. */
202  
203  #define boot_spm_busy_wait()          do{}while(boot_spm_busy())
204  
205  #define __BOOT_PAGE_ERASE         (_BV(__SPM_ENABLE) | _BV(PGERS))
206  #define __BOOT_PAGE_WRITE         (_BV(__SPM_ENABLE) | _BV(PGWRT))
207  #define __BOOT_PAGE_FILL          _BV(__SPM_ENABLE)
208  #define __BOOT_RWW_ENABLE         (_BV(__SPM_ENABLE) | _BV(__COMMON_ASRE))
209  #define __BOOT_LOCK_BITS_SET      (_BV(__SPM_ENABLE) | _BV(BLBSET))
210  
211  #define __boot_page_fill_short(address, data)   \
212  (__extension__({                                 \
213      __asm__ __volatile__                         \
214      (                                            \
215          "movw  r0, %3\n\t"                       \
216          "out %0, %1\n\t"                         \
217          "spm\n\t"                                \
218          "clr  r1\n\t"                            \
219          :                                        \
220          : "i" (_SFR_IO_ADDR(__SPM_REG)),        \
221            "r" ((uint8_t)__BOOT_PAGE_FILL),       \
222            "z" ((uint16_t)address),               \
223            "r" ((uint16_t)data)                   \
224          : "r0"                                   \
225      );                                           \
226  }))
227  
228  #define __boot_page_fill_normal(address, data)   \
229  (__extension__({                                 \
230      __asm__ __volatile__                         \
231      (                                            \
232          "movw  r0, %3\n\t"                       \
233          "sts %0, %1\n\t"                         \
234          "spm\n\t"                                \
235          "clr  r1\n\t"                            \
236          :                                        \
237          : "i" (_SFR_MEM_ADDR(__SPM_REG)),        \
238            "r" ((uint8_t)__BOOT_PAGE_FILL),       \
239            "z" ((uint16_t)address),               \
240            "r" ((uint16_t)data)                   \
241          : "r0"                                   \
242      );                                           \
243  }))
244  
245  #define __boot_page_fill_alternate(address, data)\
246  (__extension__({                                 \
247      __asm__ __volatile__                         \
248      (                                            \
249          "movw  r0, %3\n\t"                       \
250          "sts %0, %1\n\t"                         \
251          "spm\n\t"                                \
252          ".word 0xffff\n\t"                       \
253          "nop\n\t"                                \
254          "clr  r1\n\t"                            \
255          :                                        \
256          : "i" (_SFR_MEM_ADDR(__SPM_REG)),        \
257            "r" ((uint8_t)__BOOT_PAGE_FILL),       \
258            "z" ((uint16_t)address),               \
259            "r" ((uint16_t)data)                   \
260          : "r0"                                   \
261      );                                           \
262  }))
263  
264  #define __boot_page_fill_extended(address, data) \
265  (__extension__({                                 \
266      __asm__ __volatile__                         \
267      (                                            \
268          "movw  r0, %4\n\t"                       \
269          "movw r30, %A3\n\t"                      \
270          "sts %1, %C3\n\t"                        \
271          "sts %0, %2\n\t"                         \
272          "spm\n\t"                                \
273          "clr  r1\n\t"                            \
274          :                                        \
275          : "i" (_SFR_MEM_ADDR(__SPM_REG)),        \
276            "i" (_SFR_MEM_ADDR(RAMPZ)),            \
277            "r" ((uint8_t)__BOOT_PAGE_FILL),       \
278            "r" ((uint32_t)address),               \
279            "r" ((uint16_t)data)                   \
280          : "r0", "r30", "r31"                     \
281      );                                           \
282  }))
283  
284  #define __boot_page_fill_extended_short(address, data) \
285  (__extension__({                                 \
286      __asm__ __volatile__                         \
287      (                                            \
288          "movw  r0, %4\n\t"                       \
289          "movw r30, %A3\n\t"                      \
290          "out %1, %C3\n\t"                        \
291          "out %0, %2\n\t"                         \
292          "spm\n\t"                                \
293          "clr  r1\n\t"                            \
294          :                                        \
295          : "i" (_SFR_IO_ADDR(__SPM_REG)),        \
296            "i" (_SFR_IO_ADDR(RAMPZ)),            \
297            "r" ((uint8_t)__BOOT_PAGE_FILL),       \
298            "r" ((uint32_t)address),               \
299            "r" ((uint16_t)data)                   \
300          : "r0", "r30", "r31"                     \
301      );                                           \
302  }))
303  
304  #define __boot_page_erase_short(address)        \
305  (__extension__({                                 \
306      __asm__ __volatile__                         \
307      (                                            \
308          "out %0, %1\n\t"                         \
309          "spm\n\t"                                \
310          :                                        \
311          : "i" (_SFR_IO_ADDR(__SPM_REG)),        \
312            "r" ((uint8_t)__BOOT_PAGE_ERASE),      \
313            "z" ((uint16_t)address)                \
314      );                                           \
315  }))
316  
317  
318  #define __boot_page_erase_normal(address)        \
319  (__extension__({                                 \
320      __asm__ __volatile__                         \
321      (                                            \
322          "sts %0, %1\n\t"                         \
323          "spm\n\t"                                \
324          :                                        \
325          : "i" (_SFR_MEM_ADDR(__SPM_REG)),        \
326            "r" ((uint8_t)__BOOT_PAGE_ERASE),      \
327            "z" ((uint16_t)address)                \
328      );                                           \
329  }))
330  
331  #define __boot_page_erase_alternate(address)     \
332  (__extension__({                                 \
333      __asm__ __volatile__                         \
334      (                                            \
335          "sts %0, %1\n\t"                         \
336          "spm\n\t"                                \
337          ".word 0xffff\n\t"                       \
338          "nop\n\t"                                \
339          :                                        \
340          : "i" (_SFR_MEM_ADDR(__SPM_REG)),        \
341            "r" ((uint8_t)__BOOT_PAGE_ERASE),      \
342            "z" ((uint16_t)address)                \
343      );                                           \
344  }))
345  
346  #define __boot_page_erase_extended(address)      \
347  (__extension__({                                 \
348      __asm__ __volatile__                         \
349      (                                            \
350          "movw r30, %A3\n\t"                      \
351          "sts  %1, %C3\n\t"                       \
352          "sts %0, %2\n\t"                         \
353          "spm\n\t"                                \
354          :                                        \
355          : "i" (_SFR_MEM_ADDR(__SPM_REG)),        \
356            "i" (_SFR_MEM_ADDR(RAMPZ)),            \
357            "r" ((uint8_t)__BOOT_PAGE_ERASE),      \
358            "r" ((uint32_t)address)                \
359          : "r30", "r31"                           \
360      );                                           \
361  }))
362  #define __boot_page_erase_extended_short(address)      \
363  (__extension__({                                 \
364      __asm__ __volatile__                         \
365      (                                            \
366          "movw r30, %A3\n\t"                      \
367          "out  %1, %C3\n\t"                       \
368          "out %0, %2\n\t"                         \
369          "spm\n\t"                                \
370          :                                        \
371          : "i" (_SFR_IO_ADDR(__SPM_REG)),        \
372            "i" (_SFR_IO_ADDR(RAMPZ)),            \
373            "r" ((uint8_t)__BOOT_PAGE_ERASE),      \
374            "r" ((uint32_t)address)                \
375          : "r30", "r31"                           \
376      );                                           \
377  }))
378  
379  #define __boot_page_write_short(address)        \
380  (__extension__({                                 \
381      __asm__ __volatile__                         \
382      (                                            \
383          "out %0, %1\n\t"                         \
384          "spm\n\t"                                \
385          :                                        \
386          : "i" (_SFR_IO_ADDR(__SPM_REG)),        \
387            "r" ((uint8_t)__BOOT_PAGE_WRITE),      \
388            "z" ((uint16_t)address)                \
389      );                                           \
390  }))
391  
392  #define __boot_page_write_normal(address)        \
393  (__extension__({                                 \
394      __asm__ __volatile__                         \
395      (                                            \
396          "sts %0, %1\n\t"                         \
397          "spm\n\t"                                \
398          :                                        \
399          : "i" (_SFR_MEM_ADDR(__SPM_REG)),        \
400            "r" ((uint8_t)__BOOT_PAGE_WRITE),      \
401            "z" ((uint16_t)address)                \
402      );                                           \
403  }))
404  
405  #define __boot_page_write_alternate(address)     \
406  (__extension__({                                 \
407      __asm__ __volatile__                         \
408      (                                            \
409          "sts %0, %1\n\t"                         \
410          "spm\n\t"                                \
411          ".word 0xffff\n\t"                       \
412          "nop\n\t"                                \
413          :                                        \
414          : "i" (_SFR_MEM_ADDR(__SPM_REG)),        \
415            "r" ((uint8_t)__BOOT_PAGE_WRITE),      \
416            "z" ((uint16_t)address)                \
417      );                                           \
418  }))
419  
420  #define __boot_page_write_extended(address)      \
421  (__extension__({                                 \
422      __asm__ __volatile__                         \
423      (                                            \
424          "movw r30, %A3\n\t"                      \
425          "sts %1, %C3\n\t"                        \
426          "sts %0, %2\n\t"                         \
427          "spm\n\t"                                \
428          :                                        \
429          : "i" (_SFR_MEM_ADDR(__SPM_REG)),        \
430            "i" (_SFR_MEM_ADDR(RAMPZ)),            \
431            "r" ((uint8_t)__BOOT_PAGE_WRITE),      \
432            "r" ((uint32_t)address)                \
433          : "r30", "r31"                           \
434      );                                           \
435  }))
436  #define __boot_page_write_extended_short(address)      \
437  (__extension__({                                 \
438      __asm__ __volatile__                         \
439      (                                            \
440          "movw r30, %A3\n\t"                      \
441          "out %1, %C3\n\t"                        \
442          "out %0, %2\n\t"                         \
443          "spm\n\t"                                \
444          :                                        \
445          : "i" (_SFR_IO_ADDR(__SPM_REG)),        \
446            "i" (_SFR_IO_ADDR(RAMPZ)),            \
447            "r" ((uint8_t)__BOOT_PAGE_WRITE),      \
448            "r" ((uint32_t)address)                \
449          : "r30", "r31"                           \
450      );                                           \
451  }))
452  
453  #define __boot_rww_enable_short()                      \
454  (__extension__({                                 \
455      __asm__ __volatile__                         \
456      (                                            \
457          "out %0, %1\n\t"                         \
458          "spm\n\t"                                \
459          :                                        \
460          : "i" (_SFR_IO_ADDR(__SPM_REG)),        \
461            "r" ((uint8_t)__BOOT_RWW_ENABLE)       \
462      );                                           \
463  }))
464  
465  #define __boot_rww_enable()                      \
466  (__extension__({                                 \
467      __asm__ __volatile__                         \
468      (                                            \
469          "sts %0, %1\n\t"                         \
470          "spm\n\t"                                \
471          :                                        \
472          : "i" (_SFR_MEM_ADDR(__SPM_REG)),        \
473            "r" ((uint8_t)__BOOT_RWW_ENABLE)       \
474      );                                           \
475  }))
476  
477  #define __boot_rww_enable_alternate()            \
478  (__extension__({                                 \
479      __asm__ __volatile__                         \
480      (                                            \
481          "sts %0, %1\n\t"                         \
482          "spm\n\t"                                \
483          ".word 0xffff\n\t"                       \
484          "nop\n\t"                                \
485          :                                        \
486          : "i" (_SFR_MEM_ADDR(__SPM_REG)),        \
487            "r" ((uint8_t)__BOOT_RWW_ENABLE)       \
488      );                                           \
489  }))
490  
491  /* From the mega16/mega128 data sheets (maybe others):
492  
493       Bits by SPM To set the Boot Loader Lock bits, write the desired data to
494       R0, write "X0001001" to SPMCR and execute SPM within four clock cycles
495       after writing SPMCR. The only accessible Lock bits are the Boot Lock bits
496       that may prevent the Application and Boot Loader section from any
497       software update by the MCU.
498  
499       If bits 5..2 in R0 are cleared (zero), the corresponding Boot Lock bit
500       will be programmed if an SPM instruction is executed within four cycles
501       after BLBSET and SPMEN (or SELFPRGEN) are set in SPMCR. The Z-pointer is 
502       don't care during this operation, but for future compatibility it is 
503       recommended to load the Z-pointer with $0001 (same as used for reading the 
504       Lock bits). For future compatibility It is also recommended to set bits 7, 
505       6, 1, and 0 in R0 to 1 when writing the Lock bits. When programming the 
506       Lock bits the entire Flash can be read during the operation. */
507  
508  #define __boot_lock_bits_set_short(lock_bits)                    \
509  (__extension__({                                           \
510      uint8_t value = (uint8_t)(~(lock_bits));               \
511      __asm__ __volatile__                                   \
512      (                                                      \
513          "ldi r30, 1\n\t"                                   \
514          "ldi r31, 0\n\t"                                   \
515          "mov r0, %2\n\t"                                   \
516          "out %0, %1\n\t"                                   \
517          "spm\n\t"                                          \
518          :                                                  \
519          : "i" (_SFR_IO_ADDR(__SPM_REG)),                  \
520            "r" ((uint8_t)__BOOT_LOCK_BITS_SET),             \
521            "r" (value)                                      \
522          : "r0", "r30", "r31"                               \
523      );                                                     \
524  }))
525  
526  #define __boot_lock_bits_set(lock_bits)                    \
527  (__extension__({                                           \
528      uint8_t value = (uint8_t)(~(lock_bits));               \
529      __asm__ __volatile__                                   \
530      (                                                      \
531          "ldi r30, 1\n\t"                                   \
532          "ldi r31, 0\n\t"                                   \
533          "mov r0, %2\n\t"                                   \
534          "sts %0, %1\n\t"                                   \
535          "spm\n\t"                                          \
536          :                                                  \
537          : "i" (_SFR_MEM_ADDR(__SPM_REG)),                  \
538            "r" ((uint8_t)__BOOT_LOCK_BITS_SET),             \
539            "r" (value)                                      \
540          : "r0", "r30", "r31"                               \
541      );                                                     \
542  }))
543  
544  #define __boot_lock_bits_set_alternate(lock_bits)          \
545  (__extension__({                                           \
546      uint8_t value = (uint8_t)(~(lock_bits));               \
547      __asm__ __volatile__                                   \
548      (                                                      \
549          "ldi r30, 1\n\t"                                   \
550          "ldi r31, 0\n\t"                                   \
551          "mov r0, %2\n\t"                                   \
552          "sts %0, %1\n\t"                                   \
553          "spm\n\t"                                          \
554          ".word 0xffff\n\t"                                 \
555          "nop\n\t"                                          \
556          :                                                  \
557          : "i" (_SFR_MEM_ADDR(__SPM_REG)),                  \
558            "r" ((uint8_t)__BOOT_LOCK_BITS_SET),             \
559            "r" (value)                                      \
560          : "r0", "r30", "r31"                               \
561      );                                                     \
562  }))
563  
564  /*
565     Reading lock and fuse bits:
566  
567       Similarly to writing the lock bits above, set BLBSET and SPMEN (or 
568       SELFPRGEN) bits in __SPMREG, and then (within four clock cycles) issue an 
569       LPM instruction.
570  
571       Z address:       contents:
572       0x0000           low fuse bits
573       0x0001           lock bits
574       0x0002           extended fuse bits
575       0x0003           high fuse bits
576  
577       Sounds confusing, doesn't it?
578  
579       Unlike the macros in pgmspace.h, no need to care for non-enhanced
580       cores here as these old cores do not provide SPM support anyway.
581   */
582  
583  /** \ingroup avr_boot
584      \def GET_LOW_FUSE_BITS
585      address to read the low fuse bits, using boot_lock_fuse_bits_get
586   */
587  #define GET_LOW_FUSE_BITS           (0x0000)
588  /** \ingroup avr_boot
589      \def GET_LOCK_BITS
590      address to read the lock bits, using boot_lock_fuse_bits_get
591   */
592  #define GET_LOCK_BITS               (0x0001)
593  /** \ingroup avr_boot
594      \def GET_EXTENDED_FUSE_BITS
595      address to read the extended fuse bits, using boot_lock_fuse_bits_get
596   */
597  #define GET_EXTENDED_FUSE_BITS      (0x0002)
598  /** \ingroup avr_boot
599      \def GET_HIGH_FUSE_BITS
600      address to read the high fuse bits, using boot_lock_fuse_bits_get
601   */
602  #define GET_HIGH_FUSE_BITS          (0x0003)
603  
604  /** \ingroup avr_boot
605      \def boot_lock_fuse_bits_get(address)
606  
607      Read the lock or fuse bits at \c address.
608  
609      Parameter \c address can be any of GET_LOW_FUSE_BITS,
610      GET_LOCK_BITS, GET_EXTENDED_FUSE_BITS, or GET_HIGH_FUSE_BITS.
611  
612      \note The lock and fuse bits returned are the physical values,
613      i.e. a bit returned as 0 means the corresponding fuse or lock bit
614      is programmed.
615   */
616  #define boot_lock_fuse_bits_get_short(address)                   \
617  (__extension__({                                           \
618      uint8_t __result;                                      \
619      __asm__ __volatile__                                   \
620      (                                                      \
621          "ldi r30, %3\n\t"                                  \
622          "ldi r31, 0\n\t"                                   \
623          "out %1, %2\n\t"                                   \
624          "lpm %0, Z\n\t"                                    \
625          : "=r" (__result)                                  \
626          : "i" (_SFR_IO_ADDR(__SPM_REG)),                  \
627            "r" ((uint8_t)__BOOT_LOCK_BITS_SET),             \
628            "M" (address)                                    \
629          : "r0", "r30", "r31"                               \
630      );                                                     \
631      __result;                                              \
632  }))
633  
634  #define boot_lock_fuse_bits_get(address)                   \
635  (__extension__({                                           \
636      uint8_t __result;                                      \
637      __asm__ __volatile__                                   \
638      (                                                      \
639          "ldi r30, %3\n\t"                                  \
640          "ldi r31, 0\n\t"                                   \
641          "sts %1, %2\n\t"                                   \
642          "lpm %0, Z\n\t"                                    \
643          : "=r" (__result)                                  \
644          : "i" (_SFR_MEM_ADDR(__SPM_REG)),                  \
645            "r" ((uint8_t)__BOOT_LOCK_BITS_SET),             \
646            "M" (address)                                    \
647          : "r0", "r30", "r31"                               \
648      );                                                     \
649      __result;                                              \
650  }))
651  
652  /** \ingroup avr_boot
653      \def boot_signature_byte_get(address)
654  
655      Read the Signature Row byte at \c address.  For some MCU types,
656      this function can also retrieve the factory-stored oscillator
657      calibration bytes.
658  
659      Parameter \c address can be 0-0x1f as documented by the datasheet.
660      \note The values are MCU type dependent.
661  */
662  
663  #define __BOOT_SIGROW_READ (_BV(__SPM_ENABLE) | _BV(SIGRD))
664  
665  #define boot_signature_byte_get_short(addr) \
666  (__extension__({                      \
667        uint16_t __addr16 = (uint16_t)(addr);     \
668        uint8_t __result;                         \
669        __asm__ __volatile__                      \
670        (                                         \
671          "out %1, %2\n\t"                        \
672          "lpm %0, Z" "\n\t"                      \
673          : "=r" (__result)                       \
674          : "i" (_SFR_IO_ADDR(__SPM_REG)),        \
675            "r" ((uint8_t) __BOOT_SIGROW_READ),   \
676            "z" (__addr16)                        \
677        );                                        \
678        __result;                                 \
679  }))
680  
681  #define boot_signature_byte_get(addr) \
682  (__extension__({                      \
683        uint16_t __addr16 = (uint16_t)(addr);     \
684        uint8_t __result;                         \
685        __asm__ __volatile__                      \
686        (                                         \
687          "sts %1, %2\n\t"                        \
688          "lpm %0, Z" "\n\t"                      \
689          : "=r" (__result)                       \
690          : "i" (_SFR_MEM_ADDR(__SPM_REG)),       \
691            "r" ((uint8_t) __BOOT_SIGROW_READ),   \
692            "z" (__addr16)                        \
693        );                                        \
694        __result;                                 \
695  }))
696  
697  /** \ingroup avr_boot
698      \def boot_page_fill(address, data)
699  
700      Fill the bootloader temporary page buffer for flash 
701      address with data word. 
702  
703      \note The address is a byte address. The data is a word. The AVR 
704      writes data to the buffer a word at a time, but addresses the buffer
705      per byte! So, increment your address by 2 between calls, and send 2
706      data bytes in a word format! The LSB of the data is written to the lower 
707      address; the MSB of the data is written to the higher address.*/
708  
709  /** \ingroup avr_boot
710      \def boot_page_erase(address)
711  
712      Erase the flash page that contains address.
713  
714      \note address is a byte address in flash, not a word address. */
715  
716  /** \ingroup avr_boot
717      \def boot_page_write(address)
718  
719      Write the bootloader temporary page buffer 
720      to flash page that contains address.
721      
722      \note address is a byte address in flash, not a word address. */
723  
724  /** \ingroup avr_boot
725      \def boot_rww_enable()
726  
727      Enable the Read-While-Write memory section. */
728  
729  /** \ingroup avr_boot
730      \def boot_lock_bits_set(lock_bits)
731  
732      Set the bootloader lock bits.
733  
734      \param lock_bits A mask of which Boot Loader Lock Bits to set.
735  
736      \note In this context, a 'set bit' will be written to a zero value.
737      Note also that only BLBxx bits can be programmed by this command.
738  
739      For example, to disallow the SPM instruction from writing to the Boot
740      Loader memory section of flash, you would use this macro as such:
741  
742      \code
743      boot_lock_bits_set (_BV (BLB11));
744      \endcode
745  
746      \note Like any lock bits, the Boot Loader Lock Bits, once set,
747      cannot be cleared again except by a chip erase which will in turn
748      also erase the boot loader itself. */
749  
750  /* Normal versions of the macros use 16-bit addresses.
751     Extended versions of the macros use 32-bit addresses.
752     Alternate versions of the macros use 16-bit addresses and require special
753     instruction sequences after LPM.
754  
755     FLASHEND is defined in the ioXXXX.h file.
756     USHRT_MAX is defined in <limits.h>. */ 
757  
758  #if defined(__AVR_ATmega161__) || defined(__AVR_ATmega163__) \
759      || defined(__AVR_ATmega323__)
760  
761  /* Alternate: ATmega161/163/323 and 16 bit address */
762  #define boot_page_fill(address, data) __boot_page_fill_alternate(address, data)
763  #define boot_page_erase(address)      __boot_page_erase_alternate(address)
764  #define boot_page_write(address)      __boot_page_write_alternate(address)
765  #define boot_rww_enable()             __boot_rww_enable_alternate()
766  #define boot_lock_bits_set(lock_bits) __boot_lock_bits_set_alternate(lock_bits)
767  
768  #elif (FLASHEND > USHRT_MAX)
769  
770  /* Extended: >16 bit address */
771  #define boot_page_fill(address, data) __boot_page_fill_extended_short(address, data)
772  #define boot_page_erase(address)      __boot_page_erase_extended_short(address)
773  #define boot_page_write(address)      __boot_page_write_extended_short(address)
774  #define boot_rww_enable()             __boot_rww_enable_short()
775  #define boot_lock_bits_set(lock_bits) __boot_lock_bits_set_short(lock_bits)
776  
777  #else
778  
779  /* Normal: 16 bit address */
780  #define boot_page_fill(address, data) __boot_page_fill_short(address, data)
781  #define boot_page_erase(address)      __boot_page_erase_short(address)
782  #define boot_page_write(address)      __boot_page_write_short(address)
783  #define boot_rww_enable()             __boot_rww_enable_short()
784  #define boot_lock_bits_set(lock_bits) __boot_lock_bits_set_short(lock_bits)
785  
786  #endif
787  
788  /** \ingroup avr_boot
789  
790      Same as boot_page_fill() except it waits for eeprom and spm operations to
791      complete before filling the page. */
792  
793  #define boot_page_fill_safe(address, data) \
794  do { \
795      boot_spm_busy_wait();                       \
796      eeprom_busy_wait();                         \
797      boot_page_fill(address, data);              \
798  } while (0)
799  
800  /** \ingroup avr_boot
801  
802      Same as boot_page_erase() except it waits for eeprom and spm operations to
803      complete before erasing the page. */
804  
805  #define boot_page_erase_safe(address) \
806  do { \
807      boot_spm_busy_wait();                       \
808      eeprom_busy_wait();                         \
809      boot_page_erase (address);                  \
810  } while (0)
811  
812  /** \ingroup avr_boot
813  
814      Same as boot_page_write() except it waits for eeprom and spm operations to
815      complete before writing the page. */
816  
817  #define boot_page_write_safe(address) \
818  do { \
819      boot_spm_busy_wait();                       \
820      eeprom_busy_wait();                         \
821      boot_page_write (address);                  \
822  } while (0)
823  
824  /** \ingroup avr_boot
825  
826      Same as boot_rww_enable() except waits for eeprom and spm operations to
827      complete before enabling the RWW mameory. */
828  
829  #define boot_rww_enable_safe() \
830  do { \
831      boot_spm_busy_wait();                       \
832      eeprom_busy_wait();                         \
833      boot_rww_enable();                          \
834  } while (0)
835  
836  /** \ingroup avr_boot
837  
838      Same as boot_lock_bits_set() except waits for eeprom and spm operations to
839      complete before setting the lock bits. */
840  
841  #define boot_lock_bits_set_safe(lock_bits) \
842  do { \
843      boot_spm_busy_wait();                       \
844      eeprom_busy_wait();                         \
845      boot_lock_bits_set (lock_bits);             \
846  } while (0)
847  
848  #endif /* _AVR_BOOT_H_ */