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Ugh this article was a total bait and switch. Kasper Lund has a lot of my respect for work he did on V8 and Dart so I was hoping this was going to be super int

Ugh this article was a total bait and switch. Kasper Lund has a lot of my respect for work he did on V8 and Dart so I was hoping this was going to be super interesting article about trying to struggle to.... make V8 run on a specific microcontroller! I think I feel more cheated because of his background and that it's highly featured on HNews.

tyingq 5y ago
He does offer a few indirect references as to why running V8 on a microcontroller would suck. Like the section on polymorphic inline cache for method resolution.
- zozbot234 5y ago
  Running V8 implies JIT and there is no JIT on most microcontrollers because they're based on Harvard architecture where no code can be written in data memory.
  - phpnode 5y ago
    V8 has an interpreter now FWIW https://v8.dev/blog/ignition-interpreter https://v8.dev/blog/ignition-interpreter
  - tyingq 5y ago
    The ESP32 has IRAM, which you can write to and execute from.
  - codys 5y ago
    A large number of microcontrollers are ARM based, which isn't Harvard architecture. I presume the thinking is that there's some massive number of Harvard architecture chips in mundane things that lets us say "most" are Harvard arch?
    - jeremyjh 5y ago
      ARM Cortex-M is a harvard architecture microcontroller. What ARM Cortex-M has in common with ARMv8 are the letters "ARM".
      - zozbot234 5y ago
        Some Cortex-M cores are described as Von Neumann. It varies by specific sub-architecture within Cortex M.
      - tyingq 5y ago
        "Modified" Harvard though. The M0 has unified main memory, so JIT wouldn't be immediately ruled out.
    - zozbot234 5y ago
      Many ARM microcontrollers have Harvard architecture as well, for improved interrupt latency compared to plain Von Neumann.
jeremyjh 5y ago
So this is a shameless bit of marketing collateral but I also learned from it. I hadn't heard of Toit before.
sebe 5y ago
The article does answer the question in the title. "Why doesn’t V8 fit on my microcontroller?" "It is fast, but prohibitively expensive in terms of memory." So there's no room for v8 on a $2 board, Toit vm and toit language have been designed from the ground up for the iot world. Tidbit, Dart team did have an iot project called dartino, before flutter took over the dart world. Anyway the article was posted on the toit website. I've been following their progress via twitter. https://twitter.com/toitware https://twitter.com/toitware https://twitter.com/toitlang https://twitter.com/toitlang
finnthehuman 5y ago
> Ugh this article was a total bait and switch. Yeah, as someone who works with microcontrollers professionally and would always love better tools to work with, this article didn't do much to sell me. It is a nice bit of marketing in the way it positioned itself. I don't think I'd be able to articulate why I'm not rushing to use this without getting called an old fogey.

tyingq 5y ago

He does offer a few indirect references as to why running V8 on a microcontroller would suck. Like the section on polymorphic inline cache for method resolution.

zozbot234 5y ago
Running V8 implies JIT and there is no JIT on most microcontrollers because they're based on Harvard architecture where no code can be written in data memory.
- phpnode 5y ago
  V8 has an interpreter now FWIW https://v8.dev/blog/ignition-interpreter https://v8.dev/blog/ignition-interpreter
- tyingq 5y ago
  The ESP32 has IRAM, which you can write to and execute from.
- codys 5y ago
  A large number of microcontrollers are ARM based, which isn't Harvard architecture. I presume the thinking is that there's some massive number of Harvard architecture chips in mundane things that lets us say "most" are Harvard arch?
  - jeremyjh 5y ago
    ARM Cortex-M is a harvard architecture microcontroller. What ARM Cortex-M has in common with ARMv8 are the letters "ARM".
    - zozbot234 5y ago
      Some Cortex-M cores are described as Von Neumann. It varies by specific sub-architecture within Cortex M.
    - tyingq 5y ago
      "Modified" Harvard though. The M0 has unified main memory, so JIT wouldn't be immediately ruled out.
  - zozbot234 5y ago
    Many ARM microcontrollers have Harvard architecture as well, for improved interrupt latency compared to plain Von Neumann.

jeremyjh 5y ago

So this is a shameless bit of marketing collateral but I also learned from it. I hadn't heard of Toit before.

sebe 5y ago

The article does answer the question in the title. "Why doesn’t V8 fit on my microcontroller?" "It is fast, but prohibitively expensive in terms of memory." So there's no room for v8 on a $2 board, Toit vm and toit language have been designed from the ground up for the iot world. Tidbit, Dart team did have an iot project called dartino, before flutter took over the dart world. Anyway the article was posted on the toit website. I've been following their progress via twitter. https://twitter.com/toitware https://twitter.com/toitware https://twitter.com/toitlang https://twitter.com/toitlang

finnthehuman 5y ago

> Ugh this article was a total bait and switch. Yeah, as someone who works with microcontrollers professionally and would always love better tools to work with, this article didn't do much to sell me. It is a nice bit of marketing in the way it positioned itself. I don't think I'd be able to articulate why I'm not rushing to use this without getting called an old fogey.