/* $Id$ */ /* * Copyright (c) 2011 Dimitri Sokolyuk * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include #include /* depends on BAUD & F_CPU env vars */ #include #define TIMEOUT (F_CPU >> 3) /* ca. 2 sec */ union { uint16_t word; uint8_t byte[2]; } data; void reboot(void) { boot_rww_enable(); ((void(*)(void))0)(); /* jump to app */ } void putch(char c) { loop_until_bit_is_set(UCSRA, UDRE); UDR = c; } uint8_t getch(void) { uint32_t counter = 0; do { if (++counter > TIMEOUT) reboot(); } while (bit_is_clear(UCSRA, RXC)); return UDR; } enum { INIT, PAGE, DATA, CKSUM }; int main(void) { uint16_t off = 0; uint8_t ch = 0; uint8_t n = 0; uint8_t sum = 0; uint8_t state = INIT; UCSRB = _BV(RXEN) | _BV(TXEN); UBRRH = UBRRH_VALUE; UBRRL = UBRRL_VALUE; UCSRA |= _BV(U2X); putch('+'); /* say hallo */ for (;;) { ch = getch(); switch (state) { case INIT: switch (ch) { case 'D': state = PAGE; break; case 'P': /* legacy: confim programming state */ putch('p'); break; case 'R': reboot(); break; } break; case PAGE: n = 0; sum = ch; off = (uint16_t)ch * SPM_PAGESIZE; state = DATA; break; case DATA: sum += ch; data.byte[n % 2] = ch; if (n % 2) boot_page_fill(off + n - 1, data.word); if (n++ == SPM_PAGESIZE) state = CKSUM; break; case CKSUM: if (sum == ch) { boot_page_erase(off); boot_spm_busy_wait(); boot_page_write(off); boot_spm_busy_wait(); putch('d'); /* confirm */ } else putch('D'); state = INIT; break; } } return 0; }