[galangalalgol]

Doesn't the lack of a flat memory model make a genral os difficult? The amiga1000 had far less processing power and about the same memory, with no mmu, but that memory model was flat. Did you have to do weird things to work around it?

[isitcontent]

The memory model is flat enough. The problem with the memory is, you only have about 200kB traditional RAM. But then, you have 8MB of PSRAM. But it requires strict 4-byte alignment, and is noticeably slower.

What makes traditional OSs difficult on this platform, is the lack of memory protection. But I am a simple man, I am not writing an OS, all I wanted was a usable shell and an apps installer, so I made that work.

[apitman]

Things change when the underlying assumptions change. Memory protection is mostly useful for multitasking, but traditional multitasking isn't always needed when your entire app starts faster than Windows can minimize a program.

[pjmlp]

Just like MS-DOS and CP/M did great with such hardware constraints.

I still think many don't understand how much is possible with a plain ESP32.

[apitman]

We should have an argument about how WASM would be the perfect app format for this.

[pjmlp]

Like USCD Pascal P-Code, M-Code, Taos, IBM TIMI, JVM, CLR, Parallax Propeller, and many others.

[numpad0]

What makes general OS difficult on a SoC is usually the lack of hardware virtual<->real RAM address translation accelerator, the MMU.

I guess it's not that important if developers had no raw pointer access so that object can be anywhere dynamically assigned(Java!!! also JavaScript and all interpreted langs). But basically all desktop OS apps are written in C and they always want single consistent virtual addresses to jump around in and none of apps work without the hardware dynamic translation.

[1718627440]

C semantics account for segmented storage, that is why two pointers holding the same bitwise address are not considered to point to the same object, when they are derived differently.

[apitman]

Can you expound on this problem a bit? I'm still pretty new to MCUs.