RISCV: ISA "Linux" or "Windows for Workgroups" - PART 1 Linux Similarities

[RISCV Opinion]

RISCV has been called "Linux for Hardware".

We have benefited from the association.

And there are valid reasons for the comparison.

Both Linux and RISCV benefited from prior art;

       Linux supporting  the POSIX ISO/IEC 9945standard;

       RISCV applying lessons learn from generations of Reduced
Instruction Architectures.

Both providing the kernel on which the larger infrastructure would be built.

      Linux providing a user interface an OS functionality only;

           nothing entered the inner circle if it was not infrastructure .

      RISCV providing a minimal base that can be expanded;

          and most notably restraining the "standard" ISA but allocating
"Custom" space for non-core.

Both carefully crafted minimalist constructs

      Linux famously avoided the Wisdom of the day, microkernels, and
instead focused on efficiency.

           Lowest latency for the critical timing portions, notably OS
invocation.

      RISCV meticulously designed instruction formats and privilege support.

           To the point of "mangling" immediate fields and providing a
single context switch register "mscratch"

Both were free to all and directly supported the hobbyist.

     Linux has continued to improve minimalist systems while
simultaneously expanding to more machine architectures and features.

           The examples of this are legion: SLUB/SLAB/SLOB, and unified
page management - an example of the more general parameterized
configuration options.

    RISCV readily implementable across multiple fabrication methods;

          from PCBs of SLI-TTL/MSI-CMOS, to standard FPGA, to shared
wafer VLSI CPU, to SoC dedicated wafers, to WSI.


And there are many more similarities that I invite the community to include.


However, various nearing ratification "extensions" are poised to thwart
the benefits RISCV has promised.

Parts to come:

- RISCV on Workgroups

- Embrace, Extend, Extinguish

- Staging: Only when Ready.

- Leveraging RISCV strengths.

- Are we too late?

- 10 steps to Recovery In Strategic Computer Victory.