I don't think it's yet complete enough to compile itself; though I haven't looked at the assembler code, I'm pretty sure it requires bitwise operations the compiler can't compile yet. Also, the compiler itself requires things like null, symbolp, eq, and atom, which it also doesn't implement yet. Without those I'm not sure that it's fair to describe its input language as Lisp, though it does support car and cdr.
But it's still super cool. A really great thing about Lisp for purposes like this is that you don't get hung up on syntax and parsing, which is the most salient part of writing a compiler but not the most important.
This is all very neat and all but could anyone please explain to me how this thing handles forward label resolution e.g. in the "if" construct? I think I know how it does that but I am very likely to be be wrong.
I got a RP2350 "Feather"[1] from Adafruit[2]. Amazing little thing, with lots of stuff built-in. The lipoly charge port is super useful and Just Works, and the STEMMA QT connector means no soldering or breadboards for simple projects. My main half-baked idea for this is to control a CPU usage monitor[3], but I also want to make some better lights for my Lego SHIELD Helicarrier, and maybe add some movement too.
And now you're telling me I can use Lisp on this? It would be interesting to see how streamlined the development process is for each one of uLisp, CircuitPython, MicroPython, and Arduino/C.
[3] Yeah I'm rambling but my end goal is to drive an LED matrix that ends up looking like btop's CPU meter. Why not just show btop on a separate small screen? That is a very good question to which I have no answer.
As I understand it, this compiles down to assembly instructions. What then assembles it to machine code? The reason I'm asking is I wanted to find out if the compiler/assembler supports compressed instructions (which are supported by the RP RISC-V core).
Edit: Yes it does support the compressed extension, although the page calls them "compact" instructions.
In the article there is a link to an earlier post with a RISC-V assembler (I think written by the same author), which generates the actual machine code
For me, it's the fact that it is a truly open standard, with no licensing entanglements. It has the potential to be a durable ecosystem, worth investing in.
I don't think it's yet complete enough to compile itself; though I haven't looked at the assembler code, I'm pretty sure it requires bitwise operations the compiler can't compile yet. Also, the compiler itself requires things like null, symbolp, eq, and atom, which it also doesn't implement yet. Without those I'm not sure that it's fair to describe its input language as Lisp, though it does support car and cdr.
But it's still super cool. A really great thing about Lisp for purposes like this is that you don't get hung up on syntax and parsing, which is the most salient part of writing a compiler but not the most important.
This is all very neat and all but could anyone please explain to me how this thing handles forward label resolution e.g. in the "if" construct? I think I know how it does that but I am very likely to be be wrong.
SBCL is a Common Lisp compiler written in Common Lisp that also can target RISC-V.
Can it run on the MCU mentioned in the post? Somehow I doubt that.
Can SBCL even target MCU boards like the pico?
Second sentence from TFA:
> You can run the compiler on the RISC-V core of a Raspberry Pi Pico 2 (or another RP2350-based board)
What article are you referring to? (Specifically, the parent comment asked about SBCL, Steel Bank Common Lisp, running on the pico 2, not about uLISP)
No more comments before coffee for me.
ulisp is an incredible achievement and has brought me a lot of joy.
There is something very fun about writing lisp for an Arduino nano, and trying to golf your intentions into ~300 characters :)
That's neat but I don't know why you'd minimize characters rather than ROM size for a microcontroller.
I got a RP2350 "Feather"[1] from Adafruit[2]. Amazing little thing, with lots of stuff built-in. The lipoly charge port is super useful and Just Works, and the STEMMA QT connector means no soldering or breadboards for simple projects. My main half-baked idea for this is to control a CPU usage monitor[3], but I also want to make some better lights for my Lego SHIELD Helicarrier, and maybe add some movement too.
And now you're telling me I can use Lisp on this? It would be interesting to see how streamlined the development process is for each one of uLisp, CircuitPython, MicroPython, and Arduino/C.
[1] https://www.adafruit.com/product/6000
[2] https://www.adafruit.com/new <-- one of my favourite places to window-shop :)
[3] Yeah I'm rambling but my end goal is to drive an LED matrix that ends up looking like btop's CPU meter. Why not just show btop on a separate small screen? That is a very good question to which I have no answer.
Rust also runs on picos and Esp32s, if that’s your jam.
As I understand it, this compiles down to assembly instructions. What then assembles it to machine code? The reason I'm asking is I wanted to find out if the compiler/assembler supports compressed instructions (which are supported by the RP RISC-V core).
Edit: Yes it does support the compressed extension, although the page calls them "compact" instructions.
In the article there is a link to an earlier post with a RISC-V assembler (I think written by the same author), which generates the actual machine code
Thanks - corrected "compact" to "compressed".
There is something about RISC-V that really inspires lots of hackers and it’s not really technical thing AFAICT.
For me, it's the fact that it is a truly open standard, with no licensing entanglements. It has the potential to be a durable ecosystem, worth investing in.
It is cool as heck that truly open hardware might actually win in our lifetimes. (ARM was an interesting start, but too much licensing).
> There is something about RISC-V that really inspires lots of hackers
"Not Arm" :)
It's a bunch of things; many of the reasons are actually technical. It's very simple to compile to RISC-V instructions.
Simplicity, it's a modern MOS 6502. Base RISC-V has even less instructions than 6502.
The same could be said of the ARM Cortex-M0+.
The Cortex-M0's Thumb-1 is a really unpleasant instruction set compared to ARM, Thumb-2, RISC-V, or ARM64.
Also it has less registers (32 vs. 256 in the zero page) and less addressing modes.
But the 6502's "registers" are much smaller and you can do much less with them. You can't really sensibly compare the two approaches so superficially.
Edit: It's a pity we missed http://www.ulisp.com/show?4W2I. It was posted (https://news.ycombinator.com/item?id=41190553) but didn't get attention. We'd have put it in the SCP for sure (https://news.ycombinator.com/item?id=26998308) if we had seen it.
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Related. Others?
uLisp: Lisp for Microcontrollers - https://news.ycombinator.com/item?id=41681705 - Sept 2024 (1 comment)
An ARM Assembler Written in Lisp - https://news.ycombinator.com/item?id=36646277 - July 2023 (31 comments)
uLisp wireless message display with a Pi Pico W - https://news.ycombinator.com/item?id=32722475 - Sept 2022 (6 comments)
Visible Lisp Computer: embedded real-time display of Lisp workspace using uLisp - https://news.ycombinator.com/item?id=30612770 - March 2022 (7 comments)
uLisp on the Raspberry Pi Pico - https://news.ycombinator.com/item?id=29970231 - Jan 2022 (14 comments)
uLisp - https://news.ycombinator.com/item?id=27036317 - May 2021 (87 comments)
Lisp Badge: A single-board computer that you can program in uLisp - https://news.ycombinator.com/item?id=23729970 - July 2020 (25 comments)
A new RISC-V version of uLisp - https://news.ycombinator.com/item?id=22640980 - March 2020 (35 comments)
uLisp – ARM Assembler in Lisp - https://news.ycombinator.com/item?id=22117241 - Jan 2020 (49 comments)
Ray tracing with uLisp - https://news.ycombinator.com/item?id=20565559 - July 2019 (10 comments)
uLisp: Lisp for microcontrollers - https://news.ycombinator.com/item?id=18882335 - Jan 2019 (16 comments)
GPS mapping application in uLisp - https://news.ycombinator.com/item?id=18466566 - Nov 2018 (4 comments)
Tiny Lisp Computer 2 - https://news.ycombinator.com/item?id=16347048 - Feb 2018 (2 comments)
uLisp – Lisp for the Arduino - https://news.ycombinator.com/item?id=11777662 - May 2016 (33 comments)
I see Lisp compilers and upvote. :)
Great work.
Gretchen! Stop trying to make Lisp happen. It’s not going to happen.