On Fri, Nov 08, 2013 at 06:17:44PM -0600, Dan McGhee wrote: > I have everything in place to boot LFS in EFI-mode. The problem is that > something is failing and the messages go by so fast that I can't see > what it is. Just like I have it set up, the laptop boots to Ubuntu if > the LFS boot failed. My problem is that I'm stymied in my troubleshooting. > > I've reasoned that the problem is probably in my grub.cfg. > [ snip EFI / grub.cfg details, I'm going to query your reasoning ]
One initial question: you are getting kernel messages when LFS fails to boot ? If so, in a conventional bios boot the showstopper is usually something like "trying to kill init" and that usually happens because rootfs= is wrong, or the device drivers and filesystem are missing. You have root=/dev/sda6, so I will be very surprised if you have fallen into that hole. Hmm, does it change to booting ubuntu _immediately_ if the LFS boot fails ? If so, I can understand why you can't see the messages, but I've no idea how to address that. My reason for questioning if this is a grub.cfg issue is that I've been reading the kernel mailing list (lkml) since before I ever found BLFS or LFS. Some days I skim most of the posts, but in the last month or two I've seen a lot of posts between kernel developers about (U)EFI. My impression is that the situation is still very fragile [to be fair, most of the threads were primarily about signing the kernel for secure boot], and I recall reading that many commits which fixed things for some people broke things for others. In particular, I had the impression that many apple machines seemed to disagree with fixes that worked on "regular" Windows EFI x86 and (perhaps) on arm. So, I think it might be a problem either with the kernel config, or with the kernel version. Since you can't boot, that isn't a very helpful observation. Can you do anything to pause it after it fails to boot LFS ? On all the machines I've ever built for (x86 with bios, and various ppc) the automatic reboot happened about 3 minutes after the boot failed, which gave me time to note some of the visible messages. Hmm, if this is a laptop then I suppose the screen might not have enough rows to see anything useful. Perhaps the same if you got an oops and the kernel state was dumped. I *guess* a way to approach this might be to take the .config from ubuntu (/boot/config-3.x.y-z-something), work out what needs to be built-in instead of modules [ lsmod on ubuntu - if it loaded, you probably need it, at least until you can boot ], and then take a similar kernel version and try that. What I mean is, IFF you are running e.g. 3.2.0-34-generic on ubuntu, then first try 3.2.0, but also try 3.2.latest. If either boots, it's a start. If both boot, go with 3.2.latest. If neither boots, I've probably wasted your time. If only 3.2.0 boots, perhaps try "broad brush" bisection between 3.2.0 and 3.2.latest [ I don't know what the latest 3.2 SUBLEVEL is, my oldest running kernel is now 3.10.something, and anyway you might not be running 3.2 in ubuntu ]. ** after you can boot, first try 3.10.latest with that .config as the input to make oldconfig please, in case that works - if so, the job is done ** e.g. if latest is .100, for "broad brush" bisection try .50, then either .25 or .75 according to whether or not that boots. Depending on available time, you might get to the latest version of _that_ kernel which boots. That would indicate that one of the commits in the next SUBLEVEL broke it. Hmm, ubuntu are doing long-term maintenance of some kernels, of which I think one is 3.8 and I'm not sure about the other - I think they are adding their versions at the fourth level [ EXTRAVERSION ]. Whatever, the first step is to try to get a kernel which boots. If you can achieve that, the next step is to move through the newer still-maintained versions. I think the following are still maintained officially - 3.2, 3.4, 3.10. If it is an "errant hardware" problem I will have to suggest that you might need to try ALL the various SUBLEVELs of whichever of those series are newer than what ubuntu runs. Hopefully .0 will work, but it is possible that a later SUBLEVEL fixes an error, only for a still-later one to break it again. Actually, once you have a .config that lets you boot LFS, I guess the most efficient thing to do would be to try 3.10.latest with that config, in case it works. [ I've added the '**' sentence above ]. I'm sorry this sounds painful (it probably will be), but EFI is not yet something that most linux users are using. For the BIOS, it took years to sort out some of the weirdnesses. And I'm sorry, my suggestion to try 3.10.latest once you have a working older .config will short-circuit a lot of what I've written (if it works). I'm sure you can find an appropriate path through the twisty maze of kernel versions, all almost alike ;-) ĸen -- das eine Mal als Tragödie, dieses Mal als Farce -- http://linuxfromscratch.org/mailman/listinfo/lfs-support FAQ: http://www.linuxfromscratch.org/lfs/faq.html Unsubscribe: See the above information page
