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.
This commit is contained in:
Stefan Rueger 2022-07-10 23:25:31 +01:00
parent 64ee4858fd
commit ff8f519a34
1 changed files with 7 additions and 10 deletions

View File

@ -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