From ff8f519a34ed4e167be442ca4abeac6f11cccdca Mon Sep 17 00:00:00 2001 From: Stefan Rueger Date: Sun, 10 Jul 2022 23:25:31 +0100 Subject: [PATCH] Fix PICKit2 ATmega2560 flash paged flash read The paged read in pickit2.c has two errors: - It drops load extended address commands unless a paged read happens at a 64k byte boundary; this is invalid when reading files with holes - It wrongly assumed that flash memory is byte addressed The fix is to carry out a load extended address command, if needed, at the beginning of each paged flash read with the correct word address. Although the pickit2_paged_load() has independent parameters page_size, addr and n_bytes, AVRDUDE only ever calls paged read/write functions with page_size and n_bytes both set to mem->page_size and addr aligned with a page boundary. Therefore, it is sufficient to set the load extended address at the beginning of each page read. --- src/pickit2.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) diff --git a/src/pickit2.c b/src/pickit2.c index 9e4be94c..ac3781f5 100644 --- a/src/pickit2.c +++ b/src/pickit2.c @@ -491,18 +491,15 @@ static int pickit2_paged_load(PROGRAMMER * pgm, AVRPART * p, AVRMEM * mem, pgm->pgm_led(pgm, ON); + if (lext) { + memset(cmd, 0, sizeof(cmd)); + avr_set_bits(lext, cmd); + avr_set_addr(lext, cmd, addr/2); + pgm->cmd(pgm, cmd, res); + } + for (addr_base = addr; addr_base < max_addr; ) { - if ((addr_base == 0 || (addr_base % /*ext_address_boundary*/ 65536) == 0) - && lext != NULL) - { - memset(cmd, 0, sizeof(cmd)); - - avr_set_bits(lext, cmd); - avr_set_addr(lext, cmd, addr_base); - pgm->cmd(pgm, cmd, res); - } - // bytes to send in the next packet -- not necessary as pickit2_spi() handles breaking up // the data into packets -- but we need to keep transfers frequent so that we can update the // status indicator bar