Save SP which is closest to the crash location, which simplifies
debugging. For serial_dump, write SP just before the dump.
For xfdump, save SP in the dump header.
This makes xfdump_dump and xfdump_full_dump_and_reset() equivalent for
stack debugging.
Now that the stack_error function is truly minimal,
we can check for stack errors much more frequently.
Also move away stack_error from ultralcd to Marlin_main.
Rename EEPROM_CRASH_ACKNOWLEDGED to EEPROM_FW_CRASH_FLAG.
Use EEPROM_FW_CRASH_FLAG to always set the last crash reason, which
simplifies handling between the online/offline variants.
Make stack_error safe, by setting the flag and restarting immediately,
so that the error can be shown after restart.
When XFLASH is not available, allow users to request _online_ crash
dumps by using D23 (since these require active user cooperation).
Once enabled, instead of just rebooting, dump memory directly to
the serial.
As similarly done with EMERGENCY_DUMP, we have two features that can be
enabled:
EMERGENCY_SERIAL_DUMP: enables dumping on crash after being requested
MENU_SERIAL_DUMP: allow triggering the same manually through the support
menu.
Create a gap between the BSS and the stack guard.
Set this gap (STACK_GUARD_MARGIN) to 32 bytes in all variants.
The gap serves two purposes:
- Detect a stack overflow earlier (falsely triggering in overtight
situations is OK!), so that we can hopefully avoid smashing
the heap and have a clean view during the dump.
- Reserve spack space itself for the stack dumping machinery,
which is going to grow the stack even further.
Remove get_stack_guard_test_value() which was unused.
As suggested by @3d-gussner, announce to the host that a dump is
available for retrieval using an action "dump_available".
Any kind of dump is announced (even if manually triggered).
To avoid reading from xflash twice, remove some duplication and return
the crash reason directly in xfdump_check_state().
If MENU_DUMP is enabled, a new entry at the end of the "Support" menu is
added that allows to dump memory for offline use.
This allows to trigger a memory dump at any moment during regular usage
(either idling or printing) and to recover the dump later even after a
hardware reset.
If EMERGENCY_DUMP is defined, crash and dump using the new xflash dump
functionality instead of just continuing with an error message.
When an emergency crash is stored, the first restart after a crash
displays a message that debug data is available and to contact support
to submit the crash for analysis.
Ensure the language data always fits the reserved space in the XFLASH.
The script *should* use the LANG_SIZE definition from "xflash_layout",
which can be obtained by preprocessing the source code.
At the moment though this step has been omitted since running
arduino-builder to preprocess the source requires extra flags passed by
build.sh. The size has been hard-coded (and it's unlikely to change
given the content size is constant for the architecture).
