Date: Wed, 1 Mar 2017 23:18:09 +0530 From: Saurav Sachidanand <sauravsachidanand@gmail.com> To: Alan Somers <asomers@freebsd.org> Cc: Warner Losh <imp@bsdimp.com>, "freebsd-hackers@freebsd.org" <freebsd-hackers@freebsd.org>, Allan Jude <allanjude@freebsd.org>, Ian Lepore <ian@freebsd.org> Subject: Re: [GSoC 2017] Original proposal: Port kernel Lua to FreeBSD Message-ID: <CACKq%2BiWgtgExz51H9RvzJ3ze8qMD2X9Lw%2Bmi4Cbi5ue3vGGqjA@mail.gmail.com> In-Reply-To: <CAOtMX2hSTpJmL81NKJVWRUZ=vq66uKTUW0VCSx9-oaqkQ7mpzw@mail.gmail.com> References: <CACKq%2BiX_V2MY9sNf-buEOO1S87dbhDv%2BPGbUEqRUVkvzz3pdvw@mail.gmail.com> <244231A2-EB18-4E58-A2B2-927F55D54950@FreeBSD.org> <CANCZdfpiiJLyLbEQnk86mfwf07JGByq5oT_1-T43iEhscEEgMg@mail.gmail.com> <f221e624-1342-7548-a3f9-806a1d25b90d@freebsd.org> <1488383213.60166.10.camel@freebsd.org> <CANCZdfoYk1v9axkT0CqUbCWOaoPrEDoJRPpPk0kk5GDjDE=-fw@mail.gmail.com> <CACKq%2BiVMd0edbOpg2Hr1bDdFmwekqt78YiCWbaY-iC16gqOW5g@mail.gmail.com> <CAOtMX2hSTpJmL81NKJVWRUZ=vq66uKTUW0VCSx9-oaqkQ7mpzw@mail.gmail.com>
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Since the language(s) to be included are chosen at compile time it wouldn't be forcing anyone to use a bloated bootloader. Wouldn't Python's richer standard library (eg: re) be useful in certain situations? On Wed, Mar 1, 2017 at 9:42 PM, Alan Somers <asomers@freebsd.org> wrote: > Python is huge, and we already have people complaining that the > bootloader doesn't fit in their boot partitions ever since it gained > GELI support. The advantage of Lua is that the embedded interpreter > is very small. I'd rather not bloat the bootloader too much. > > -Alan > > On Wed, Mar 1, 2017 at 9:08 AM, Saurav Sachidanand > <sauravsachidanand@gmail.com> wrote: >> Is it related to this project >> https://wiki.freebsd.org/SummerOfCode2014/LuaLoader ? >> Apparently, that project created a generic interface in the bootloader >> to plug in any >> interpreter, and then added Lua. >> >> How about adding Python as well, as a GSoC project? A team from Intel managed to >> get Python to run inside GRUB [1] [2]. I can use their work as a >> reference for modifying >> the Python interpreter. >> >> [1] - https://lwn.net/Articles/641244/ >> [2] - https://github.com/biosbits/bits >> >> On Wed, Mar 1, 2017 at 3:51 PM, Warner Losh <imp@bsdimp.com> wrote: >>> On Wed, Mar 1, 2017 at 8:46 AM, Ian Lepore <ian@freebsd.org> wrote: >>>> On Wed, 2017-03-01 at 16:14 +0800, Julian Elischer wrote: >>>>> On 28/2/17 2:01 am, Warner Losh wrote: >>>>> > >>>>> > On Mon, Feb 27, 2017 at 8:26 AM, Allan Jude <allanjude@freebsd.org> >>>>> > wrote: >>>>> > > >>>>> > > On February 27, 2017 5:28:41 AM PST, Saurav Sachidanand <sauravsa >>>>> > > chidanand@gmail.com> wrote: >>>>> > > > >>>>> > > > Hello FreeBSD community, >>>>> > > > >>>>> > > > I'm >>>>> > > > Saurav Sachidanand, and I'm >>>>> > > > a CS sophomore studying in India >>>>> > > > . >>>>> > > > I have an interest in operating systems development and wish to >>>>> > > > contribute >>>>> > > > to the FreeBSD community. I'm proficient with C and have some >>>>> > > > experience in >>>>> > > > kernel programming. Hence, I'd like to propose an original >>>>> > > > project for >>>>> > > > GSoC >>>>> > > > 2017 that I feel would benefit this community. >>>>> > > > >>>>> > > > In past years, the Lua interpreter was ported to run inside the >>>>> > > > Linux >>>>> > > > and >>>>> > > > NetBSD kernel [1]. Lua was chosen because it's interpreter is >>>>> > > > very >>>>> > > > small (~240 >>>>> > > > KB) compared to that of Python or Ruby, it's MIT licensed, and >>>>> > > > is >>>>> > > > almost >>>>> > > > freestanding. A working demonstration of it is a packet >>>>> > > > filtering >>>>> > > > algorithm >>>>> > > > written entirely in kernel Lua [2]. >>>>> > > > >>>>> > > > Specifically, my proposal would be to port the following that >>>>> > > > are >>>>> > > > currently >>>>> > > > written for NetBSD: >>>>> > > > - the modified Lua VM source code with _KERNEL preprocessor >>>>> > > > directives >>>>> > > > to >>>>> > > > exclude user-space functionality like floating point, the io >>>>> > > > and os >>>>> > > > module >>>>> > > > in the standard library, etc. [3] >>>>> > > > - the kernel module device driver for /dev/lua, to which Lua >>>>> > > > scripts >>>>> > > > are >>>>> > > > fed to be executed [4], [5] >>>>> > > > - the luactl user-space program to control the Lua device and a >>>>> > > > couple >>>>> > > > of >>>>> > > > sysctl variables which serve similar purpose [6], [7] >>>>> > > > >>>>> > > > And then: >>>>> > > > - run the Lua test suite targeting whatever we support in the >>>>> > > > kernel to >>>>> > > > make sure it works [8] >>>>> > > > - and write Lua bindings to the kernel interfaces that would >>>>> > > > interest >>>>> > > > the >>>>> > > > FreeBSD community >>>>> > > > >>>>> > > > Since NetBSD and FreeBSD have similar kernel interfaces >>>>> > > > (mutexes, >>>>> > > > linked >>>>> > > > lists, device switch interface), the porting shouldn't involve >>>>> > > > too much >>>>> > > > code refactoring. Also, this would all be an experiment in that >>>>> > > > we >>>>> > > > don't >>>>> > > > fully know what the real world use cases might be, but it would >>>>> > > > attract >>>>> > > > more people to writing kernel code who otherwise wouldn't >>>>> > > > because of >>>>> > > > having >>>>> > > > to do everything in C. And it would be interesting to carry out >>>>> > > > it out >>>>> > > > in >>>>> > > > FreeBSD as well since it has a larger community than NetBSD. >>>>> > > > >>>>> > > > I humbly request anyone who is interested in this project to be >>>>> > > > my >>>>> > > > potential mentor(s) for GSoC. >>>>> > > > >>>>> > > > More slides on kernel Lua in NetBSD - [9], [10]. >>>>> > > > >>>>> > > > Thanks, >>>>> > > > Saurav >>>>> > > > >>>>> > > > [1] - http://www.netbsd.org/~lneto/dls14.pdf >>>>> > > > [2] - https://www.netbsd.org/~lneto/eurobsdcon14.pdf >>>>> > > > [3] - https://github.com/jsonn/src/tree/trunk/external/mit/lua/ >>>>> > > > dist/src >>>>> > > > [4] - >>>>> > > > https://github.com/IIJ-NetBSD/netbsd-src/tree/master/sys/module >>>>> > > > s/lua >>>>> > > > [5] - >>>>> > > > https://github.com/IIJ-NetBSD/netbsd-src/tree/master/sys/module >>>>> > > > s/luasystm >>>>> > > > [6] - https://github.com/IIJ-NetBSD/netbsd-src/tree/master/sbin >>>>> > > > /luactl >>>>> > > > [7] - http://netbsd.gw.com/cgi-bin/man-cgi?lua+4+NetBSD-current >>>>> > > > [8] - http://www.lua.org/tests/ >>>>> > > > [9] - >>>>> > > > https://www.netbsd.org/gallery/presentations/mbalmer/fosdem2012 >>>>> > > > /kernel_mode_lua.pdf >>>>> > > > [10] - https://www.lua.org/wshop13/Cormack.pdf >>>>> > > > _______________________________________________ >>>>> > > > freebsd-hackers@freebsd.org mailing list >>>>> > > > https://lists.freebsd.org/mailman/listinfo/freebsd-hackers >>>>> > > > To unsubscribe, send any mail to >>>>> > > > "freebsd-hackers-unsubscribe@freebsd.org" >>>>> > > This may be quite a nice thing to have. Another upcoming use for >>>>> > > LUA in the kernel is ZFS Channel Programs. These allow a number >>>>> > > of ZFS operations to be completed as a single atomic transaction. >>>>> > > >>>>> > > I would hope we could structure this in such a way as to not end >>>>> > > up with two copies of Lua in the kernel. >>>>> > There's also a 3/4 finished lua in the boot loader that you might >>>>> > be >>>>> > able to leverage as well.... >>>>> I'd like to see that finished. While Devin has done Heroic work with >>>>> the forth in the loader, I think it's time has come. >>>>> It' be nice to have something a little less '60s. >>>>> >>>>> > >>>>> > >>>>> > Warner >>>> >>>> I was under the impression that the "lua in bootloader" work was >>>> basically done and just needed testing, which nobody has done. I think >>>> it's all sitting in the projects/lua-bootloader branch in svn. >>> >>> The branch compiles. Testing has been done, but there's some missing >>> bits. It basically kinda works for the average case, but more advanced >>> uses of the bootloader still have sharp pointy edges on them, the >>> extent of the pointy edges is unknown. At this point the rebasing of >>> the branch is non-trivial due to the merge conflicts that have crept >>> in. They don't look awful, but when I tried to use git to rebase to a >>> more modern FreeBSD, there were lots of stupid things. Maybe I'll try >>> again... >>> >>> Warner >> _______________________________________________ >> freebsd-hackers@freebsd.org mailing list >> https://lists.freebsd.org/mailman/listinfo/freebsd-hackers >> To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.org"
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