* Provide cached byte-wise read/write API
int avr_read_byte_cached(const PROGRAMMER *pgm, const AVRPART *p, const
AVRMEM *mem, unsigned long addr, unsigned char *value);
int avr_write_byte_cached(const PROGRAMMER *pgm, const AVRPART *p, const
AVRMEM *mem, unsigned long addr, unsigned char data);
int avr_flush_cache(const PROGRAMMER *pgm, const AVRPART *p);
int avr_chip_erase_cached(const PROGRAMMER *pgm, const AVRPART *p);
int avr_reset_cache(const PROGRAMMER *pgm, const AVRPART *p);
avr_read_byte_cached() and avr_write_byte_cached() use a cache if paged
routines are available and if the device memory is EEPROM or flash,
otherwise they fall back to pgm->read_byte() and pgm->write_byte(),
respectively. Byte-wise cached read always gets its data from the cache,
possibly after reading a page from the device memory. Byte-wise cached
write with an address in memory range only ever modifies the cache. Any
modifications are written to the device after calling avr_flush_cache() or
when attempting to read or write from a location outside the address range
of the device memory.
avr_flush_cache() synchronises pending writes to EEPROM and flash with the
device. With some programmer and part combinations, flash (and sometimes
EEPROM, too) looks like a NOR memory, ie, one can only write 0 bits, not 1
bits. When this is detected, either page erase is deployed (eg, with parts
that have PDI/UPDI interfaces), or if that is not available, both EEPROM
and flash caches are fully read in, a pgm->chip_erase() command is issued
and both EEPROM and flash are written back to the device. Hence, it can
take minutes to ensure that a single previously cleared bit is set and,
therefore, this routine should be called sparingly.
avr_chip_erase_cached() erases the chip and discards pending writes() to
flash or EEPROM. It presets the flash cache to all 0xff alleviating the
need to read from the device flash. However, if the programmer serves
bootloaders (pgm->prog_modes & PM_SPM) then the flash cache is reset
instead, necessitating flash memory be fetched from the device on first
read; the reason for this is that bootloaders emulate chip erase and they
won't overwrite themselves (some bootloaders, eg, optiboot ignore chip
erase commands altogether) making it truly unknowable what the flash
contents on device is after a chip erase.
For EEPROM avr_chip_erase_cached() concludes that it has been deleted if a
previously cached EEPROM page that contained cleared bits now no longer
has these clear bits on the device. Only with this evidence is the EEPROM
cache preset to all 0xff otherwise the cache discards all pending writes
to EEPROM and is left unchanged otherwise.
Finally, avr_reset_cache() resets the cache without synchronising pending
writes() to the device.
In order to get meaningful const properties for the PROGRAMMER, AVRPART and
AVRMEM arguments, some code needed to be moved around, otherwise a network of
"tainted" assignments risked rendering nothing const:
- Change void (*enable)(PROGRAMMER *pgm) to void (*enable)(PROGRAMMER *pgm,
const AVRPART *p); this allows changes in the PROGRAMMER structure after
the part is known. For example, use TPI, UPDI, PDI functions in that
programmer appropriate to the part. This used to be done later in the
process, eg, in the initialize() function, which "taints" all other
programmer functions wrt const and sometimes requires other finessing with
flags etc. Much clearer with the modified enable() interface.
- Move TPI initpgm-type code from initialize() to enable() --- note that
initpgm() does not have the info at the time when it is called whether or
not TPI is required
- buspirate.c: move pgm->flag to PDATA(pgm)->flag (so legitimate
modification of the flag does not change PROGRAMMER structure)
- Move AVRPART_INIT_SMC and AVRPART_WRITE bits from the flags field in
AVRPART to jtagmkII.c's private data flags32 fiels as FLAGS32_INIT_SMC and
FLAGS32_WRITE bits
- Move the xbeeResetPin component to private data in stk500.c as this is
needed by xbee when it saddles on the stk500 code (previously, the flags
component of the part was re-dedicated to this)
- Change the way the "chained" private data are used in jtag3.c whilst
keeping the PROGRAMMER structure read-only otherwise
- In stk500v2.c move the STK600 pgm update from stk500v2_initialize() to
stk500v2_enable() so the former keeps the PROGRAMMER structure read-only
(for const assertion).
- In usbasp change the code from changing PROGRAMMER functions late to
dispatching to TPI or regular SPI protocol functions at runtime; reason
being the decision whether to use TPI protocol is done at run-time
depending on the capability of the attached programmer
Also fixes Issue #1071, the treatment of default eecr value.
This commit replaces fixed-string buffers in PROGRAMMER, AVRPART and AVRMEM
that are dealt with by the parser and grammar. Now, string assignments are
always to const char *, ie, these are read-only strings with arbitrary
length.
config_gram.y now only needs to consider one type of string assignment.
This commit also
- Replaces the simple linear-search cache_string() function with faster
hashed cache_string(). Either way, the returned value is likely to be
shared, so should never be free()'d.
- Duplicates hvupdi_support list in pgm_dup() and frees it in pgm_free()
- Adds const qualifier to some function args in avrpart.c and pgm.c
- Hardens some functions against being called with NULL pointers
- Ensures _new() and _dup() functions for parts, programmers and memory
return a suitable memory. Out of memory triggers exit in one of three
functions, cfg_malloc(), cfg_realloc() and cfg_strdup(); there is
rarely anything useful that AVRDUDE or, for that matter, any
application compiled against libavrdude can do once you run out of
memory as AVRDUDE/libavrdude rely heavily on allocation of memory.
- Replace strdup(s) with cfg_strdup(funname, s) that exits on out of mem
- Replace malloc(n) with cfg_malloc(funname, n) that exits on out of mem
- Change multiline string scanning in lexer.l to avoid core dump
- Remove global variables string_buf and string_bug_ptr
- Ensure reading strings unescapes strings C-Style
- Ensure writing strings escapes strings C-Style again
Commit looks longer than needed as unescape() and auxiliary functions needed
to be moved from term.c (not in libavrdude) to config.c (in libavrdude).
Also changed usbdev, usbsn, usbvendor and usbproduct components from
PROGRAMMER structure to be cached string pointers rather than fixed-size
arrays. These will be initialised by pgm_new() with a pointer to nul;
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
Jan Egil Ruud
Marius Greuel