That kernel is a continuation of 9k. That's a very nice kernel (I worked with it for many years, from its creation in 2005 through NIX and, later, the Harvey years;Harvey includes 9k), but I felt that 9front was a better kernel. Historical note: I ran the DOE contract that paid for 9k, so I have a lot of fondness for it.
Alas, I could never get it to build :-) But, further, while the 9k port does a great job of accommodating all the bugs and limits of the early RISC-V SoCs, using compile- and runtime adjustments, it does so at a cost: Linux-style conditional compilation and runtime probing and function pointer setting. This results in a need to have a range of kernels. Alsok the 9front folks made it clear that the build configuration parts of 9k were not something they wanted. I am trying to see if we start with an assumption of a common foundation of "RVA23" standard parts, whether we can use a single binary; whether that kernel can dynamically chose to run in S or M mode at boot time (hence my changes to Plan 9 assumptions around address spaces); whether we can move almost all SBI responsibilities to the kernel, and prune down SBI to almost nothing but register operations (Geoff's paper points out the bugs in SBI as of its writing; as of two years later, they've gotten worse); to name a few things. I'd really like to see if running in M mode changes the amount of noise the apps experience (I'm an HPC person so come by this naturally). So, I'm benefiting from the earlier work of Geoff and Richard, but taking things in a different direction. Failure is an option. On Sun, May 24, 2026 at 1:01 PM <[email protected]> wrote: > > This might have been said before on 9fans, but for context what is the > difference between your work and what is described in > https://9p.io/sources/contrib/geoff/riscv/9k-riscv.pdf ? A continuation? A > "reboot"? > 9fans / 9fans / see discussions + participants + delivery options Permalink ------------------------------------------ 9fans: 9fans Permalink: https://9fans.topicbox.com/groups/9fans/T80b1175a2d9b4e96-M4dc4fa1ec0cab141eeaf1bfe Delivery options: https://9fans.topicbox.com/groups/9fans/subscription
