On Mon, May 22, 2017 at 11:29:29AM -0400, Aditya Basu wrote:
On Fri, May 05, 2017 at 04:58:27PM -0400, Aditya Basu wrote: > I am trying to compile and boot Linux Kernel v3.19 (64-bit version) using - > > make defconfig > make kvmconfig > make -j8 > > The compilation works out without any errors but it doesn't boot > inside qemu or my host machine. > I use the following command line parameters to linux: "debug > earlyprintk loglevel=7" > > # The boot hangs at the point - > #################################### > Booting from ROM... > early console in setup code > early console in decompress_kernel > > Decompressing Linux... Parking ELF... done. > Booting the kernel . > #################################### > > # Things I have tried so far: > - Interestingly if I uncheck the 64-bit build in config (from make > menuconfig), the resulting 32-bit kernel boots correctly. > > - Have tried running qemu with different cpus (host) + with & without kvm. > > sudo qemu-system-x86_64 -m 4G -append 'debug earlyprintk loglevel=7' > -kernel arch/x86/boot/bzImage -cpu host -enable-kvm > > I know the kernel will panic because of no root filesystem, but it > happens later in the boot process. I am basing this from booting the > 32 bit version of the kernel which prints out a lot of stuff and then > panics due to no vfs_root. > > - The 64-bit versions of kernel v4.2 and above don't have this issue - > meaning they boot correctly.
Great! Stick with newer kernels, 3.19 is really old, as is 4.2, lots and lots of things have been fixed since then, you aren't going to be able to get any help from anyone in the community if you use old kernels like that, sorry.
My primary goal is to build and boot LLVM Linux (http:// llvm.linuxfoundation.org/index.php/Main_Page). This project has patches available only till kernel v3.19. That's why I am trying to use the older version 3.19.
4.11 should build/boot using llvm, or if not, I think 4.12-rc1 can, as the remaining changes went in then. No need to stick with an obsolete kernel version just to try out an alternative compiler :) good luck! greg k-h