2013/6/21 Vladimir 'φ-coder/phcoder' Serbinenko <phco...@gmail.com>: > On 21.06.2013 11:23, Michael Chang wrote: >> Hi, >> >> The i386/pc/chainloader.c hangs when attempting to chainload other >> disk's boot sector (or mbr) with a syntax like this. Say if current >> environment setting root=hd0,msdos2. >> >> $ chainloader (hd1,msdos1)+1 >> >> However doing it this way always works. >> >> $ set root=hd1,msdos1 >> $ chainloader +1 >> >> I suppose the first syntax is valid as it should override $root [1] >> thus two cases should have identical result. But looking into the >> chainloader source it seems that the $root is always used to obtain >> the boot drive number and partition table. So there's a discrepancy if >> root is not set to the chainloader device which is explicitly >> specified in file. > No, the behaviour you see is intended consider someone copying > bootsector from (hd1,1) to (hd0,2)/boot.bin. It can still be booted with: > root=hd1,1 > chainloader (hd0,2)/boot.bin > The disk passed in %dl and where the sector is loaded from isn't > necessarily the same.
Thanks to your explaination. I now realize what has happened. Although it's sensible to me, but in syntax wise it would confuse people if they map their experience from other commands to this one. Not a big deal really, but will be great if could have some highlight about this case in the documentation. Thanks, Michael >> >> The attached file fixes the problem for me, I'd like to contribute if >> you think this is a problem or how to improve the patch. >> >> [1] http://www.gnu.org/software/grub/manual/grub.html#root >> [2] http://www.gnu.org/software/grub/manual/grub.html#chainloader >> >> Thanks, >> Michael >> >> >> >> _______________________________________________ >> Grub-devel mailing list >> Grub-devel@gnu.org >> https://lists.gnu.org/mailman/listinfo/grub-devel >> > > > > _______________________________________________ > Grub-devel mailing list > Grub-devel@gnu.org > https://lists.gnu.org/mailman/listinfo/grub-devel > _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel
