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    SubjectRe: [tip:x86/boot] x86/boot: Early parse RSDP and save it in boot_params
    On Fri, Feb 08, 2019 at 08:10:24PM +0100, Borislav Petkov wrote:
    >On Fri, Feb 08, 2019 at 11:02:48AM -0800, Guenter Roeck wrote:
    >> Hi,
    >>
    >> On Fri, Feb 01, 2019 at 03:01:11AM -0800, tip-bot for Chao Fan wrote:
    >> > Commit-ID: 3a63f70bf4c3a17f5d9c9bf3bc3288a23bdfefce
    >> > Gitweb: https://git.kernel.org/tip/3a63f70bf4c3a17f5d9c9bf3bc3288a23bdfefce
    >> > Author: Chao Fan <fanc.fnst@cn.fujitsu.com>
    >> > AuthorDate: Wed, 23 Jan 2019 19:08:48 +0800
    >> > Committer: Borislav Petkov <bp@suse.de>
    >> > CommitDate: Fri, 1 Feb 2019 11:52:55 +0100
    >> >
    >> > x86/boot: Early parse RSDP and save it in boot_params
    >> >
    >> > The RSDP is needed by KASLR so parse it early and save it in
    >> > boot_params.acpi_rsdp_addr, before KASLR setup runs.
    >> >
    >> > RSDP is needed by other kernel facilities so have the parsing code
    >> > built-in instead of a long "depends on" line in Kconfig.
    >> >
    >> > [ bp:
    >> > - Trim commit message and comments
    >> > - Add CONFIG_ACPI dependency in the Makefile
    >> > - Move ->acpi_rsdp_addr assignment with the rest of boot_params massaging in extract_kernel().
    >> > ]
    >> >
    >>
    >> This patch causes x86_64 boots with efi32 bios to crash early and hard
    >> (before any console output is seen).
    >>
    >> Sample qemu command line:
    >>
    >> qemu-system-x86_64 -kernel arch/x86/boot/bzImage -M q35 -cpu SandyBridge \
    >> -no-reboot -snapshot -smp 4 \
    >> -bios OVMF-pure-efi-32.fd \
    >> -m 1G \
    >> -usb -device usb-storage,drive=d0 \
    >> -drive file=rootfs.squashfs,if=none,id=d0,format=raw \
    >> --append 'earlycon=uart8250,io,0x3f8,9600n8 root=/dev/sda rootwait panic=-1 console=ttyS0' \
    >> -nographic
    >>
    >> This is with qemu 3.1, though details other than "-bios OVMF-pure-efi-32.fd"
    >> don't really matter.
    >>
    >> Files used above are available from https://github.com/groeck/linux-build-test/.
    >>
    >> The patch can not be reverted alone, but
    >>
    >> Revert "x86/boot/KASLR: Limit KASLR to extract the kernel in immovable memory only"
    >> Revert "x86/boot: Parse SRAT table and count immovable memory regions"
    >> Revert "x86/boot: Early parse RSDP and save it in boot_params"
    >>
    >> fixes the problem.
    >
    >Does it per chance at least continue booting if you return 0 and early
    >from efi_get_rsdp_addr() ?
    >
    >Chao, pls take a look.

    Sorry for delay, last several days were holiday, so I was away from
    keyboard. I will take a look.

    Thanks,
    Chao Fan
    >
    >Thx.
    >
    >--
    >Regards/Gruss,
    > Boris.
    >
    >Good mailing practices for 400: avoid top-posting and trim the reply.
    >
    >


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