Write mapped program memory

[leventelist]

I'm playing with an AVR64DD32 chip, and I want to store data in the flash memory runtime. I started looking at the program space utilities, but I soon realized it is a read-only library. I started mixing the memcpy() functuin with ccp_write_spm, and I came up with this one:

#include <avr/io.h>

#define dest_hi r25
#define dest_lo r24
#define src_hi r23
#define src_lo r22
#define len_hi r21
#define len_lo r20

#ifndef CCP_SPM_gc
#define CCP_SPM_gc	0x9D	/* SPM Instruction Protection  */
#endif

#ifndef NVMCTRL_CMD_FLWR_gc
#define NVMCTRL_CMD_FLWR_gc 0x02
#endif

.global flash_memcpy
.type flash_memcpy, @function

flash_memcpy:
  movw r30, src_lo
  movw r26, dest_lo
  movw r28, len_lo

; Set SPM to magic value
  ldi	r18, CCP_SPM_gc
  ldi r19, NVMCTRL_CMD_FLWR_gc
  out CCP, r18
  sts NVMCTRL_CTRLA, r19
.L_memcpy_loop:
  ld r0, Z+
  st X+, r0
  sbiw r28, 0x01
  brne .-8

I haven't tested this yet. It assumes that the written memory area is mapped to the data space.

My question is that would it be possible to include this in the avr-libc once this code stabilizes?

[sprintersb]

There are no plans to add such features to the lib, but maybe it could be added to the FAQ or so?