It appears a kernel panic is happening immediately while attempting to boot 4.12-rc3, it doesn't happen on 4.12-rc2. Adding earlyprintk=efi to the grub command line options, I get the following message (which explains why the bootloader stops at 'loading initial ramdisk...'):
This was meticulously copied from a photo of a GRUB screen, this change is undoubtedly the culprit: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/diff/arch/x86/mm/pat.c?id=v4.12-rc3&id2=v4.12-rc2 (direct commit at) https://github.com/torvalds/linux/commit/cbed27cdf0e3f7ea3b2259e86b9e34df02be3fe4 [ 0.000000] Kernel panic - not syncing: x86/PAT: PAT enabled, but not supported by secondary CPU [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.12.0-041200rc3-generic #201705282131 [ 0.000000] Hardware name: HP HP Spectre x360 Convertible /802D, BIOS F.45 04/21/2017 [ 0.000000] Call Trace: [ 0.000000] dump_stack+0x63/0x8d [ 0.000000] panic+0xe4/0x22d [ 0.000000] pat_init+0x13d/0x140 [ 0.000000] generic_set_all+0x1ab/0x300 [ 0.000000] mtrr_bp_init+0x1e5/0x227 [ 0.000000] setup_arch+0x53a/0xca8 [ 0.000000] ? printk+0x52/0x6e [ 0.000000] ? early_idt_handler_array+0x120/0x120 [ 0.000000] start_kernel+0xb7/0x46c [ 0.000000] ? early_idt_handler_array+0x120/0x120 [ 0.000000] x86_64_start_reservations+0x29/0x2b [ 0.000000] x86_64_start_kernel+0x154/0x177 [ 0.000000] secondary_startup_64+0x9f/0x9f [ 0.000000] ---[ end Kernel panic - not syncing: x86/PAT: PAT enabled, but not supported by secondary CPU [ 0.000000] This change causes a kernel panic on my Intel 5500U processor, I literally cannot boot my computer. This commit results in a serious regression for multicore Intel CPUs, 4.12-rc3 and drm-tip result in an immediate kernel panic attempting to boot. This is unacceptable. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1694561 Title: kernel panic attempting to boot kernel 4.12-rc3 Status in linux package in Ubuntu: New Bug description: I have an HP Spectre x360 Convertible laptop with an Intel 5500U SoC. In short, I am completely unable to boot kernel 4.12-rc3, even though I could boot from 4.12-rc2 perfectly fine. The loading screen does not appear at all, instead GRUB remains stuck on "Loading initial ramdisk ...". Please help. I don't know how to identify what is wrong because I am completely unable to boot the OS to begin with. Needless to say, this is a major problem. Here is my hardware: H/W path Device Class Description ==================================================== system HP Spectre x360 Convertible (N5R94UA) /0 bus 802D /0/0 memory 64KiB BIOS /0/10 memory 32KiB L1 cache /0/11 memory 32KiB L1 cache /0/12 memory 256KiB L2 cache /0/13 memory 4MiB L3 cache /0/14 processor Intel(R) Core(TM) i7-5500U CPU @ 2.40GH /0/16 memory 8GiB System Memory /0/16/0 memory 4GiB Row of chips Synchronous 1600 MHz /0/16/1 memory 4GiB Row of chips Synchronous 1600 MHz /0/100 bridge Broadwell-U Host Bridge -OPI /0/100/2 display Broadwell-U Integrated Graphics /0/100/3 multimedia Broadwell-U Audio Controller /0/100/14 bus Wildcat Point-LP USB xHCI Controller /0/100/14/0 usb1 bus xHCI Host Controller /0/100/14/0/1 input USB Receiver /0/100/14/0/3 multimedia HP Truevision Full HD /0/100/14/0/4 input Touchscreen /0/100/14/0/5 input ITE Device(8350) /0/100/14/0/7 communication Bluetooth wireless interface /0/100/14/1 usb2 bus xHCI Host Controller /0/100/16 communication Wildcat Point-LP MEI Controller #1 /0/100/1c bridge Wildcat Point-LP PCI Express Root Port /0/100/1c/0 generic RTS5227 PCI Express Card Reader /0/100/1c.2 bridge Wildcat Point-LP PCI Express Root Port /0/100/1c.2/0 wlo1 network Wireless 7265 /0/100/1f bridge Wildcat Point-LP LPC Controller /0/100/1f.2 storage Wildcat Point-LP SATA Controller [AHCI /0/100/1f.3 bus Wildcat Point-LP SMBus Controller /0/1 scsi0 storage /0/1/0.0.0 /dev/sda disk 512GB SAMSUNG MZNTE512 /0/1/0.0.0/1 /dev/sda1 volume 449MiB Windows NTFS volume /0/1/0.0.0/2 /dev/sda2 volume 99MiB Windows FAT volume /0/1/0.0.0/3 /dev/sda3 volume 15MiB reserved partition /0/1/0.0.0/4 /dev/sda4 volume 15EiB Windows FAT volume /0/1/0.0.0/5 /dev/sda5 volume 838MiB Windows NTFS volume /0/1/0.0.0/6 /dev/sda6 volume 146GiB Windows NTFS volume /0/1/0.0.0/7 /dev/sda7 volume 89GiB EXT4 volume /0/1/0.0.0/8 /dev/sda8 volume 8099MiB Linux swap volume /1 power PK03056XL To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1694561/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
