Ok, thanks for your explanation. -------- Original Message -------- Subject: Install LFS on Vortex86SX (486SX core) From: [EMAIL PROTECTED] To: LFS Support List <lfs-support@linuxfromscratch.org> Date: Dienstag, 04. Dezember 2007 16:07:26
> When you don't have a floating point coprocessor or built in floating point > support, the processor will throw an exception when a program tries to > execute floating point instructions. The FP emulation code traps those > exceptions and emulates the coprocessor. > > As for other insructions, outside the kernel its pretty rare to use embedded > assembly, so the 586&beyond-specific code would only be present because gcc > saw an optimisation if it used it. However, during the lfs build process, > you'll be specifying the build target, so gcc will know it can't use those > instructions. That's why it was suggested you look at cross-lfs: your target > environment is really a different environment than the one you're planning to > build on, and therefore you need a cross-compiler. > > > Sent from my BlackBerry device on the Rogers Wireless Network > > -----Original Message----- > From: Andreas Hofer <[EMAIL PROTECTED]> > > Date: Tue, 04 Dec 2007 10:45:45 > To:LFS Support List <lfs-support@linuxfromscratch.org> > Subject: Re: Install LFS on Vortex86SX (486SX core) > > > -------- Original Message -------- > Subject: Install LFS on Vortex86SX (486SX core) > From: Wilco Beekhuizen <[EMAIL PROTECTED]> > To: LFS Support List <lfs-support@linuxfromscratch.org> > Date: Montag, 03. Dezember 2007 22:59:51 > >> 2007/12/3, Andreas Hofer <[EMAIL PROTECTED]>: >>> Hi all, >>> >>> I want to install LFS on a Vortex86SX controller produced by the >>> taiwanese company DMP. Its instruction set is claimed to be 100% >>> compatible to i486SX, thus lacking floating point instructions and >>> anything beyond a 486. >>> >>> First thing I tried was boot the live CD on that thing but the kernel >>> crashes very soon. So I want to sort of cross build LFS for the >>> Vortex86SX on my notebook (Core2Duo 1.6GHz Ubuntu 7.10). >>> >>> Question: Is that possible and how? What do I have to do that the >>> binaries incl. tool chain will run on the target? >> It's not that difficult. >> First of all you probably need the math emulation from the kernel. >> That way linux can use the floating point instructions which some apps >> probably need. >> After that optimize everything for i386 or i486 (see gcc optimization >> manual) on your core 2 duo. The compiled binaries can run both on your >> core 2 duo and on your 486 so no need to cross compile! > > But wouldn't some of the compiled packages eventually require floating > point instructions or instructions not covered by the 486 instruction > set if I dont explicitly specify that target cpu? How does the build > procedure of vanilla LFS know which instruction set to use and if > floating point instructions are allowed? > > Cheers, > > Andreas > -- http://linuxfromscratch.org/mailman/listinfo/lfs-support FAQ: http://www.linuxfromscratch.org/lfs/faq.html Unsubscribe: See the above information page
