lua FLASH script

[tehn]

normal EVAL mode is just REPL. takes a string and then evaluates it upon completion.

functions to enable flash writing:

• erase flash
• start flash chunk
• (receive a lot of strings that are not eval'd)
• stop flash chunk
• (chunk is then evaluated for errors(loadstring()), then written to flash, then executed if it checks out(pcall())

[trentgill]

from #8
for error checking i was thinking we stream serial to RAM buffer, restart the lua VM, and run loadstring() on the new program. then we run a simple lua program that tests the system is functioning (and not eg. in an infinite loop), which can timeout (resulting in error condition), or succeed, causing the program to be written to flash.

before running loadstring we could run a checksum which the command-line util would send at end of each upload. i believe stm32 has an on-board MD5 (or similar) calculator so this shouldn't be difficult to implement. i'm uncertain how reliable we can anticipate the serial communication to be. a simpler approach would be to have a failed upload simply retry once, and error out after second attempt.

[trentgill]

this is working now.

• send the command ^^s to start transmission
• then send your chunks of lua code.
• code longer than 64chars should be wrapped in a multi-line block (3 backticks ```) before and after.
• code longer than 1024chars needs to be sent as separate multi-line blocks due to RAM limitation on the device. can fix in future.
• send ^^e to finish the transmission. this will load & execute the code. if it passes without error, it will be written to flash.
  NOTE: currently the environment is not restarted at this point.

[tehn]

fantastic!

should i create a doc to gather these little usage notes?

[trentgill]

allo. it’s in the readme already!

…

On Dec 27, 2018, at 8:17 AM, brian crabtree ***@***.***> wrote: fantastic! should i create a doc to gather these little usage notes? — You are receiving this because you modified the open/close state. Reply to this email directly, view it on GitHub <#10 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAD4_TlrIDuVaQcesX7HwK4RTdx4ddjtks5u9MhTgaJpZM4W3LHq>.

[tehn]

ah, sorry! it's hard to keep track of force commits to master without correlating PR's

when you close an issue you could paste the commit number which would reference the change... but again that's not too important until we have more people working on the code