From: Luke Kenneth Casson Leighton Date: Sat, 18 Apr 2020 13:54:10 +0000 (+0100) Subject: minor shuffle X-Git-Tag: convert-csv-opcode-to-binary~2843 X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=4f0884c185ad73cfad32065de4220f0a133c8954;p=libreriscv.git minor shuffle --- diff --git a/openpower/isans_letter.mdwn b/openpower/isans_letter.mdwn index 2ee0499f8..7b242c68d 100644 --- a/openpower/isans_letter.mdwn +++ b/openpower/isans_letter.mdwn @@ -2,6 +2,21 @@ # Letter regarding ISAMUX / NS +## Why has Libre-SOC chosen PowerPC ? + +For a hybrid CPU-VPU-GPU, intended for mass-volume adoption in tablets, +netbooks, chromebooks and industrial embedded (SBC) systems, our choice +was between Nyuzi, MIAOW, RISC-V, PowerPC, MIPS and OpenRISC. + +Of all the options, the PowerPC architecture is more complete and far more +mature. It also has a deeper adoption by Linux distributions. + +Following IBM's release of the Power Architecture instruction set to the +Linux Foundation in August 2019 the barrier to using it is no more than +that of using RISC-V. We are encouraged that the OpenPOWER Foundation is +supportive of what we are doing and helping, e.g by putting us in touch +with people who can help us. + ## Summary * We propose the standardisation of the way that the PowerPC Instruction @@ -20,21 +35,6 @@ distributions will very deliberately run unmodified on our ISA, including full compatibility with illegal instruction requirements. -## Why has Libre-SOC chosen PowerPC ? - -For a hybrid CPU-VPU-GPU, intended for mass-volume adoption in tablets, -netbooks, chromebooks and industrial embedded (SBC) systems, our choice -was between Nyuzi, MIAOW, RISC-V, PowerPC, MIPS and OpenRISC. - -Of all the options, the PowerPC architecture is more complete and far more -mature. It also has a deeper adoption by Linux distributions. - -Following IBM's release of the Power Architecture instruction set to the -Linux Foundation in August 2019 the barrier to using it is no more than -that of using RISC-V. We are encouraged that the OpenPOWER Foundation is -supportive of what we are doing and helping, e.g by putting us in touch -with people who can help us. - ## One CPU multiple ISAs This is a quick overview of the way that we would like to add changes @@ -84,7 +84,7 @@ will be (have to be) usable without the need for an expensive system call overhead (because some of the instructions needed will be in extremely tight inner loops). -# Summary of Libre-SOC Commercial Project +# About Libre-SOC Commercial Project The Libre-SOC Commercial Product is a hybrid GPU-GPU-VPU intended for mass-volume production. There is no separate GPU, because the CPU @@ -131,5 +131,6 @@ Therefore, to meet our business objectives: With all impractical options eliminated the only remaining responsible option is to extend the POWER ISA in an atomically-managed (IANA-style) formal fashion, whilst (critically and absolutely essentially) always -providing a PCR compatibility mode that is fully POWER compliant. +providing a PCR compatibility mode that is fully POWER compliant, including +all illegal instruction traps.