2009/12/4 Vladimir 'φ-coder/phcoder' Serbinenko <phco...@gmail.com>: > Robert Millan wrote: >> On Thu, Dec 03, 2009 at 06:27:07PM -0600, richardvo...@gmail.com wrote: >> >>> 2009/12/3 Vladimir 'φ-coder/phcoder' Serbinenko <phco...@gmail.com>: >>> >>>> Chris Jones wrote: >>>> >>>>> I am trying to have grub boot off a partition on a USB stick. >>>>> >>>>> >>>>> >>>> You can't chainload to disk invisible by BIOS. But you can load >>>> supported OSes from it. >>>> >>> What would be necessary to enable chainload to such devices? Install >>> an IRQ 19 handler? >>> >> >> Yeah, something like that. In essence, GRUB acting as a BIOS. Sounds awful, >> but hey we already have "efiemu". >> >> > It's by far not the same thing. EfiEmu emulates only RuntimeServices. > EFI has two types of functions: BootServices and RuntimeServices. > BootServices are only available when boot loader is running and are > terminated on kernel launch. RuntimeServices are always available but > have very small number of functions. And actually GRUB acts only as a > loader to efiemu??.o and real functions are contained in efiemu??.o > which is quite small > For BIOS disks emulations we would need much more functions but we could > adopt a similar approach. E.g: > bioshook usbbios.o <parameters> > chainloader (usb0,1)+1 > usbbiso.o may of course be compiled from GRUB files but has to be > standalone. There are few tricky parts associated with this process but > basically it would be an overblown drivemap. > > But I don't see any real reason to make even small fraction of required > effort since GRUB2 is able to load many free OS directly and so can load > them of an BIOS-invisible disks without any problems. Some free OS are > still out of GRUB family like Minix is but I would gladly accept a port > of it (which is orders of magnitude easier to do) > As of proprietary OS I think we need to support them only to the etent > of what they are able to do themselves. Documentation on such OS are > often scarce and anything we do may completely break with new version.
SCSI adapter vendors manage to implement IRQ 19 in a way that provides universal OS support, I don't see how this would be different. > And all of this only to make good to someone who would like to see every > free software die? Not all supporters of free software share that philosophy, quite a few of us like to be able to tell people "that proprietary software you use, well, it works better with free software". And sometimes free software is enriched by playing well with closed-source. For example, more people would dual-boot if there was a grub-tools package for Windows and Mac OS that added "Reboot to linux" to the start menu (by changing the default boot selection in the grub config). If grub-win existed which could install grub from inside Windows, we'd have even more users of both grub and free OSes to dual-boot with. And a Windows driver that jumped directly to grub code at an appropriate point during shutdown (i.e. after flushing disk write caches, which is probably when anti-virus drivers unload) thereby avoiding the BIOS POST delays and making dual-booting even faster and less painless would equate to even more users. I happen to have a licence for VMWare workstation 6.x which emulates a USB host controller (IIRC devices include emulated mouse as well as real devices attached to the host, including mass storage), but doesn't support booting from it. This annoyed me at one point when I was trying to prepare a bootable USB stick and couldn't test it. So I'm willing to give this a shot. Which Linux distribution do most of you use for grub development (I value the fact that commands to install the correct version of bzr, which I've not used before, were recently posted to the list). That was for Debian Lenny, but would I get started faster with another version? NB: I'm most experienced with gentoo, which is definitely NOT a quick start. Ben Voigt _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org http://lists.gnu.org/mailman/listinfo/grub-devel
