I've heard some say that crosscompiling is a big win Sent from Nine ________________________________ From: Gordan Bobic <gordan at redsleeve.org> Sent: Dec 23, 2016 10:38 AM To: Conversations around CentOS on ARM hardware Subject: Re: [Arm-dev] How to chroot from x86 to arm? Userspace emulation won't be meaningfully faster. There is no real alternative to getting a faster ARM machine. On the cheaper end, an decently specced 8 core (4+4) can be had for under $200. Samsung Chromebook 2 is more expensive but I find it more convenient. On the higher end, a Gigabyte MP30-AR0/AR1 is a monster and it takes standard DDR3 DIMMs, but it is quite expensive. I got one specifically for compiling packages. If you decide to go down that route, if you rebuild the kernel with the more reasonable 4KB page size, you can run a 32-bit chroot or docker container on an aarch64 host (that is the setup I use). I filled mine up with 128GB of RAM, so even bloadware like LibreOffice and web browsers can compile entirely on tmpfs, which helps significantly. On Fri, Dec 23, 2016 at 6:18 PM, Stephen John Smoogen <smooge at gmail.com> wrote: > > On 23 December 2016 at 02:35, mo.ucina <mo.ucina at gmail.com> wrote: > > Hello Guys, > > > > I have been doing centos package compiling on arm hardware for a while now , > > and it has been going OK . One drawback is that some bigger packages would > > run for 10hrs to compile . I would like to speed up that process , and > > compile on a much more powerful machine . I tried cross-compiling but ended > > up with issues when the arm package got contaminated with i386 libraries no > > matter what I tired . > > > > I also tried qemu VM running on my core2duo 4 core desktop machine . This > > worked OK as packages were perfect , but it was slower to compile than using > > arm hardware . Same package that took 10 hrs on arm hw , compiled for 3 and > > a half days on the desktop . > > > > My question is if I used a chroot approach to run the emulation will this be > > quicker than a qemu VM . If so can anyone please share their instructions on > > how to configure a chroot to run a centos 7 arm image on a x86 desktop. > > I am probably misunderstanding what you are wanting.. but my initial > thought is that you can't. > > The ARM uses a completely different computer architecture to x86_64. > This means that you can't just chroot into an arm environment because > the underlying processor (x86_64) isn't changing. It is still going to > try and interpret machine code 32 to be one thing even if on an ARM > that meant something completely different. [Also the fact that even if > machine code 32 was the same the ARM has different number of registers > and other internals than an x86] > > You are running into the same problems we have had with ARM > development over the last N years. The only solutions are > > a) Patience with the slow hardware you have. > b) Get more hardware but still have patience > c) Get large scale server hardware and have patience. > > The emulation problem you are running into is pretty much standard > because of the translation of a RISC architecture on a CISC > architecture. The most off the shelf ARM systems are equivalent to a > P400 MHZ from the early 2000's in some ways but also faster in others. > [Trying to use a P400 to compile say texlive is a multi day event > while on an arm system it might be only 10-20 hours.] You have a > slightly better emulation result if you have an 64 bit arm 'emulate' a > 32 bit arm but that is hardware dependent and still requires patience. > > > > > > > Best Regards > > > > Milorad > > > > _______________________________________________ > > Arm-dev mailing list > > Arm-dev at centos.org > > https://lists.centos.org/mailman/listinfo/arm-dev > > > > -- > Stephen J Smoogen. > _______________________________________________ > Arm-dev mailing list > Arm-dev at centos.org > https://lists.centos.org/mailman/listinfo/arm-dev -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.centos.org/pipermail/arm-dev/attachments/20161223/2f531047/attachment-0006.html>