Great, thanks! Gabe
On Wed, Feb 27, 2019 at 4:41 AM Sandipan Das <[email protected]> wrote: > Hi Gabe, > > Thanks for looking into this. > > On 23/02/19 3:02 AM, Gabe Black wrote: > > Hi Sandipan, I saw your power changes which are appreciated. The power > ISA > > has been neglected for a while and could use some attention. Could you > > please introduce yourself and give some context for your series of > changes? > > > > Sure. I was looking for a way to provide a mailing list style cover letter > when pushing changes but unfortunately, could not find a way to provide one > via gerrit. > > I currently work as a Linux kernel developer for IBM's Linux Technology > Center > (LTC) with a focus on some of the Power architecture-related bits. > > IBM is interested in building an open-source simulation ecosystem for the > community > (which includes both academia and industry) for enabling research on the > Power > architecture. This will also be useful for the OpenPOWER ecosystem. > > These development efforts are part of an university collaboration between > IBM > and the Department of Computer Science and Engineering at National > Institute of > Technology, Karnataka (NITK). We have been working on this since 2017 and > our > primary goal is to make gem5 capable of booting the Linux kernel with a > multi- > processor configuration. As of now, we have been able to complete the > following > phases: > > 1. Support for 64-bit ISA v3.0B (the latest one, corresponds to the new > POWER9 > CPUs) integer instructions. This includes adding new ones and making > sure > existing ones are fixed if broken and a move to little-endian byte > order. > The focus is on integer instructions only, as the kernel does not use > much > of the floating-point and vector instructions. > > 2. Support for PowerPC 64-bit ELF ABI v2 based programs in Syscall > Emulation > mode. > > 3. Support for a minimal platform capable of running bare-metal programs in > Full System mode. > > 4. Support for Radix Tree-based address translation (vaddr -> paddr) as > this > is what the latest POWER9 processors (the hardware that supports ISA > v3.0) > use. > > 5. Support for fault handling and basic interrupts. This includes page > fault > handling, timer interrupts, system call, etc. > > 6. Support for booting a minimal Linux kernel on a single CPU with a bare > minimal peripheral configuration and an initramfs image embedded in the > vmlinux binary that has a basic init program. > > My association with IBM began as a masters student at NITK where I worked > on > finishing phases 1 and 2 (patches of which I authored) with mentoring from: > Dr. Basavaraj Talawar, Assistant Professor at Dept. of CSE, NITK > Gautham Shenoy, Linux kernel engineer at IBM LTC > Madhavan Srinivasan, Linux kernel engineer at IBM LTC > Anju T Sudhakar, Linux kernel engineer at IBM LTC > > After graduating, I joined IBM full-time where I am continuing my > association > with this project as a mentor for students who have worked or are working > on > finishing the subsequent phases. Right now, we are looking at upstreaming > the > phase 1 and 2 patches which are absolute prerequisites the next set of > patches. > > > I suspect not many (or any) of the maintainers here have a strong working > > knowledge of power so please forgive silly questions as your CLs are > > reviewed. We also tend to be pretty busy and may not get through them all > > for a while, but I'm at least hoping to tackle a few of them every now > and > > then. > > > > No problem. We are open to any sort of questions or feedback. Quite a few > things have changed since ISA v2.06 (what gem5 supports as of now) and we > will be happy to address any of your concerns. > > All of our code is based on publicly available documentation. I am > including > the relevant links for anyone wanting to take a look. Hope this helps. > > [1] Power ISA v3.0B > https://openpowerfoundation.org/?resource_lib=power-isa-version-3-0 > > [2] PowerPC 64-bit ELF ABI v2 > > https://openpowerfoundation.org/?resource_lib=64-bit-elf-v2-abi-specification-power-architecture > > > Feel free to put a Signed-off-by on your CLs, but you don't need to do > that > > in this project if you don't want to. I suspect git/gerrit may even yell > at > > you if the Change-Id the last line of your CL, although I'm not certain > of > > that. > > > > I think all my patches already have a Signed-off-by and Change-Id :) > > > Gabe > > > > - Sandipan > > _______________________________________________ gem5-dev mailing list [email protected] http://m5sim.org/mailman/listinfo/gem5-dev
