For paged read/write early AVRDUDE implementations of the STK500 v1 protocol
communicated a word address (below a_div=2) or byte address (a_div=1) based
on the following code irrespective of which memories were used:
if(m->op[AVR_OP_LOADPAGE_LO] || m->op[AVR_OP_READ_LO])
a_div = 2;
else
a_div = 1;
This turned out to be a bug: it really should have been a_div=2 for flash and
a_div=1 for eeprom. At the time presumably no one noted because Atmel was at
the cusp of replacing their FW 1.x with FW 2 (and the STK500 v2 protocol).
It seems that the world (optiboot, Arduino as ISP, ...) has compensated for
the bug by assuming AVRDUDE sends *all* eeprom addresses as word addresses.
Actually these programmers overcompensated for the bug because for six out of
the 146 known SPI programmable parts with eeprom and page size > 1, AVRDUDE
would still send the eeprom addresses as byte addresses (ATmega8 ATmega8A
ATmega64 ATmega64A ATmega128 ATmega128A) owing to above code.
It makes no sense to correct the bug now seeing that virtually no one uses
the old 2005 STK 500 v1 firmware. This commit now follows optiboot, Arduino
as ISP and other projects, and simply sends all addresses for paged read or
write as word addresses. There are no longer (little known) exceptions for
ATmega8 et al that surprised some optiboot etc users.
The function avr_set_addr_mem(AVRMEM *mem, int opnum, unsigned char *cmd,
unsigned long addr) is meant to replace avr_set_addr(OPCODE *op, unsigned
char *cmd, unsigned long addr) in future.
avr_set_addr_mem() has more information about the context of the task in that
it knows the memory size, memory page size, whether or not the memory is a
flash memory (which gets words addressees supplied) and, crucially, knows
which SPI operation it is meant to compute the address bits for.
avr_set_addr_mem() first computes the interval of bit numbers that must be
supplied for the SPI command to stand a chance to work. The function only
sets those address bits that are needed. Once all avr_set_addr() function
calls have been replaced by avr_set_addr_mem(), the SPI commands that need an
address can afford to declare in avrdude.conf all 16 address bits in the
middle two bytes of the SPI command. This over-declaration will be corrected
during runtime by avr_set_addr_mem(). One consequence of this is that parts
can inherit smaller or larger memories from parents without the need to use
different SPI codes in avrdude.conf. Another consequence is that
avr_set_addr_mem() can, and does, tell the caller whether vital address bits
were not declared in the SPI opcode. During parsing of avrdude.conf this
might be utilised to generate a corresponding warning. This will uncover
problematic SPI codes in avrdude.conf that in the past went undetected.
As the address bit numbers in the SPI opcodes are highly systematic, they
don't really need to be specified. Each bit can therefore be described as one
of the characters 0 (always 0), 1 (always 1), x (don't care, but will be set
as 0), a (a copy of the correct bit of the byte or word address of read,
write, load, pagewrite or load extended address command of memories with more
than one byte), i (input bit for a load/write) or o (output bit from a read).
The bits therefore do not need to be individually separated.
If a string in the list of strings that describe an SPI opcode does *not*
contain a space *and* is longer than 7 characters, it is interpreted as a
compact bit-pattern representation. The characters 0, 1, x, a, i and o will
be recognised as the corresponding bit, whilst any of the characters ., -, _
or / can act as arbitrary visual separators, which are ignored. Examples:
loadpage_lo = "0100.0000--000x.xxxx--xxaa.aaaa--iiii.iiii";
loadpage_lo = "0100.0000", "000x.xxxx", "xxaa.aaaa", "iiii.iiii";
loadpage_lo = "0100.0000", "000x.xxxx.xxaa.aaaa", "iiii.iiii";
loadpage_lo = "0100.0000-000x.xxxx--xxaa.aaaa-iiii.iiii";
loadpage_lo = "0100.0000/000x.xxxx/xxaa.aaaa/iiii.iiii";
The compact format is an extension of the current format, which remains
valid. Both, the compact and the traditional specification can be mixed in
different strings, albeit not in the same string:
load_ext_addr = "0100.1101", "0000.0000.0000", "0 0 0 a16", "0000.0000";
This commit changes the philosophy whenever avrdude.conf encounters the
same memory of a part for the second time or whenever a memory is
described that, through inheritance, already existed: AVRDUDE no longer
zaps the memory, it rather extends it.
Therefore, avrdude.conf.in's entry for ATmega128RFA1, which inherits from
the ATmega2561, needs a line `load_ext_addr = NULL;` in its flash memory
description to zap the inherited load_ext_addr SPI command.
Other than this, avrdude.conf.in needs no other change in order to effect
the same internal representation proving earlier updates to the .conf.in
file correct that manually ensured inheritance of memory contents.
When an SPI command has a lone 'a' the initialisation now is as would be
expected by all commands that take an address. Atmel's opcodes for SPI
programming are consistent in this respect. This commit makes specifying
the bit number in avrdude.conf optional. Instead of
read_lo = "0 0 1 0 0 0 0 0 0 0 a13 a12 a11 a10 a9 a8 a7 a6 a5 a4 a3 a2 a1 a0 o o o o o o o o";
one can now use
read_lo = "0 0 1 0 0 0 0 0 0 0 a a a a a a a a a a a a a a o o o o o o o o";
Some 90% of the space of AVRPART and some 50% of PROGRAMMER is occupied by a
4 kB array config_file[] that contains the configuration file name. In
preparation of developer options that output a raw dump of the part
descriptions, this commit changes the config_file components from a large
array, which is duplicated in each part and programmer description, to a
cached string for each config file allowing for smaller raw dumps.
This commit also changes the config file name to its realpath(), eg, shortens
unwarranted `/bin/../etc/` file name components. It also changes the global
variable names `infile` and `fileno` to cfg_infile and cfg_fileno for an ever
so slight improvement of code clarity.
Stefan Rueger
MCUdude