I've been looking at doing a Fuzix port to the ESP32, and have been investigating using the MMU. It seems to be oddly restrictive, and the PID system which goes with it is rather peculiar --- limitations such as not being able to access the compiler helper routines in the ROM while the MMU is active...

(Sorry, never got a notification from the forum software...) It looks like SOC_RESERVE_MEMORY_REGION only configures heap allocation, and doesn't actually modify the linker script --- I still get code mapped to the bits of SRAM0 that I need even if I reserve it all. I have a nasty feeling that I may...

I would like to tell ESP-IDF to completely ignore certain memory areas --- SRAM0 and 2, mostly. This will be used by custom non-FreeRTOS code. Is there a way to tell the configuration tool to do this?

Having done some more poring through the Technical Reference I see that there's actually quite a lot of things which don't work unless you're in supervisor mode (PID 0 or 1). So no, setting the PID globally to 2 won't work because SRAM1 and ROM0/1 will become unavailable. I think the only option her...

Last year I did a port of Fuzix (a minimal Unix-like operating system) to the ESP8266; it worked really well. (<plug>http://cowlark.com/2021-02-09-esp8266-fuzix</plug>) I'd like to now do a port for the ESP32. As the ESP32 has a MMU, it'd be really nice to use it. This would have a number of benefit...

That is correct, the ESP32 cannot store instructions in external RAM. The later chips (ESP32S2, ESP32S3) are able to; perhaps you can use one of those. Curses! Unfortunately I'm targeting a ESP32-WROVER and ESP32-WROOM, so I have to use the classic ESP32. I think swap's probably my best option. I d...

I've been looking at doing a Fuzix port (a very small, light-weight Unix clone) for the ESP32. I've got a ESP32-WROVER device, which means it's got 8MB of external QSPI SRAM. What I'd really like to do is to split this into 4MB for process data and 4MB for process code; the programs would actually b...

I'd rather not have a full ESP platform emulator, if possible --- I just want to run code fragments, and having to produce full deployable binaries with serial drivers etc in them is a pain. Is there anything which just emulates the CPU core? Preferably a library I can embed into another application...

I want to port a compiler to produce code that will run on an ESP8266 and an ESP32. In order to run compiler tests, I'm looking for an open source LX6 emulator --- it doesn't need to emulate any of the hardware, just the CPU core. Does anyone know of one? Searching finds lots of hits of emulators fo...