Add small bytecode language for watchfaces

[pipe01]

I've implemented a small bytecode assembly language intended for making watchfaces without recompiling InfiniTime. Right now it's only a proof of concept and I'm open to any ideas and improvements. The program is currently being loaded from a hardcoded path in the external LittleFS file system, but the idea is to let users choose any fle. It's also not very optimized for memory, as it's only a proof of concept.

You can try a sample out in InfiniEmu, currently the ASM screen is the app with the eye icon. The firmware is running the following assembly code, which only takes 78 bytes when compiled:

showStatusIcons

createLabel
dup
storeLocal 0

push #0
push %TEXT_FONT
push #4
setStyleLocalFont

createLabel
dup
dup
dup
storeLocal 1

push date
loadString
setLabelText

push #0
push #0
push #60
setObjectAlign

push #0
push %TEXT_COLOR
push #0x999999
setStyleLocalColor

startPeriodicRefresh

refresh:
    loadLocal 0
    dup
    pushCurrentTime
    push format
    loadString
    formatDateTime
    setLabelText

    realignObject

    waitRefresh
    push refresh
    jump

format: .str %H:%M
date: .str MON 6 FEB 2024

[github-actions]

Build size and comparison to main:

Section	Size	Difference
text	383180B	5972B
data	940B	0B
bss	63556B	0B

[everypizza1]

It looks like the battery and charging icons are duplicated when you exit, at least in the emulator:

[pipe01]

Oh you're right, it isn't being cleaned up.

[0x0000ff]

That's cool. I'm not too clued up on assembly, but is there an assembler available for this or did you hand-write the machine code?

[pipe01]

I'm using a crude assembler written in Go, I'll release a proper one if this PR gets merged or if you want to toy around with it. Maybe some visual programming thing would be cool too, but that's just an idea.