[DOC] Add M997 Restart Page

[reloxx13]

Add page for M997 Restart gcode command

New:

MarlinFirmware/Marlin#13281
MarlinFirmware/Marlin#15209
MarlinFirmware/Marlin#7768 (comment)
https://reprap.org/wiki/G-code#M997:_Perform_in-application_firmware_update

[reloxx13]

Unsure about flag since: 2.0.0 ?

[p3p]

M997 only restarts because the LPC176x (and now some STMF1) only require restarted to flash the firmware.bin file already copied to the sd card, the command is actually Perform in-application firmware update as stated in the rep-rap gcode list.

For some future implementations this command could do much more than just restarting.

[shitcreek]

LMK when this is ready to be merged

[shitcreek]

@reloxx13 is this ready to be merged now?

[reloxx13]

heya,
from my side, yes. i dunno if @p3p wanted (or want me) to add sth.

[p3p]

I was trying to explain that M997 isn't a Restart command ^^ that's just what it does on platforms where restarting triggers a firmware flash. So the naming is a bit off.

Using it as a restart command could be mentioned though, I just don't wan't Marlins documentation to conflict with the 'official' reprap gcode list.

[reloxx13]

I was trying to explain that M997 isn't a Restart command ^^ that's just what it does on platforms where restarting triggers a firmware flash. So the naming is a bit off.

it executes eg.
NVIC_SystemReset(); or nvic_sys_reset();

Updating firmware is "a bonus" since some boards will always update after a restart if there is a firmware file on sd and only if it is supported by the bootloader.
There may boards which does not flash on boot but still could support M997 restart.

That was the reason i called it "Restart".

[p3p]

Updating firmware is "a bonus" since some boards will always update after a restart if there is a firmware file on sd and only if it is supported by the bootloader.

No that's the wrong way round, as the reprap standard states M997 flashes the firmware, it's the restart that is just a function of performing that action.

I realise that the implementation I added does just restart, but again that is only because it is necessary to perform the firmware flash on those platforms.

In my opinion the Marlin documentation should state that M997 performs a firmware update, mentioning that on some platforms (LPC176x), or specific boards in the STM32 case, this is done by performing a restart and letting the bootloader take care of it.

[reloxx13]

@p3p pls review :)

[p3p]

looks good, although LPC176x is a platform not a board and STM32 covers 3 separate platforms, .. I'm not sure how many STM32 boards actually support this.

[shitcreek]

I think it's good enough. LMK if there needs to be any correction.