The device I've got is ESP32-WROOM-32. None of the boards I've seen that use it bother with external memory, so memory is limited, especially the way it's partitioned.
On Fri, Aug 9, 2019 at 3:50 PM Charles Forsyth <charles.fors...@gmail.com> wrote: > The ESP32 has got several MMUs. The characteristics are different > depending on the part that a given MMU accesses (flash, ROM, SRAM, external > memory). > Some things are accessed using Memory Protection Units instead, which > control access by Process ID, but don't do mapping. Others including some > of the SRAMs are accessed through > an MMU that can do virtual to physical mapping. The MMUs for internal > SRAM0 and 2 choose protection for a given physical page as none, one or all > of PIDs 2 to 7, with the virtual address that > maps to it. PIDs 0 and 1 can access everything. PID 0 can execute > privileged instructions. > A large chunk of SRAM (SRAM 1) has only Memory Protection and no > translation. The external memory MMU is the most general (most > conventional). > > On Fri, Aug 9, 2019 at 3:19 PM Bakul Shah <ba...@bitblocks.com> wrote: > >> esp32 doesn’t have an mmu, right? >> >> On Jul 26, 2019, at 03:30, Charles Forsyth <charles.fors...@gmail.com> >> wrote: >> >> I was thinking of doing that since I've got an ESP-32 for some reason >> >> On Fri, Jul 26, 2019 at 7:38 AM Cyber Fonic <cyberfo...@gmail.com> wrote: >> >>> I was reading the post Why Didn't Plan 9 Succeed >>> <https://news.ycombinator.com/item?id=20527650> on Hacker News. >>> >>> Made me think that Plan 9 for IoT system of systems could be viable. >>> >>> To that end, ESP-32 modules look capable enough to run Plan 9, but is >>> there a Plan 9 C compiler for Xtensa ISA CPUs? >>> >>>
