Thread (37 messages) 37 messages, 7 authors, 2024-08-23

Re: [PATCH linux-next v3 05/14] crash: clean up kdump related config items

From: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Date: 2024-08-22 09:37:17
Also in: kexec, linux-arm-kernel, linux-mips, linux-riscv, linux-s390, linux-sh, lkml, loongarch

Hi Baoquan,

On Thu, 2024-08-22 at 17:17 +0800, Baoquan He wrote:
quoted
The change to enable CONFIG_CRASH_DUMP by default apparently broke the boot
on 32-bit Power Macintosh systems which fail after GRUB with:

	"Error: You can't boot a kdump kernel from OF!"

We may have to turn this off for 32-bit Power Macintosh systems.

See this thread on debian-powerpc ML: https://lists.debian.org/debian-powerpc/2024/07/msg00001.html
If so, fix need be made.

We may need change in ARCH_SUPPORTS_CRASH_DUMP of ppc, can you or anyone
post a patch? I don't know how to identify 32-bit Power Macintosh.

arch/powerpc/Kconfig:
===
config ARCH_SUPPORTS_CRASH_DUMP
        def_bool PPC64 || PPC_BOOK3S_32 || PPC_85xx || (44x && !SMP)
        
config ARCH_SELECTS_CRASH_DUMP
        def_bool y
        depends on CRASH_DUMP
        select RELOCATABLE if PPC64 || 44x || PPC_85xx
......
config PHYSICAL_START
        hex "Physical address where the kernel is loaded" if PHYSICAL_START_BOOL
        default "0x02000000" if PPC_BOOK3S && CRASH_DUMP && !NONSTATIC_KERNEL
        default "0x00000000"
I think the architecture does support crash dumps, but I think the kernel has to
be booted from kexec in this case. Booting a kernel with CRASH_DUMP enabled won't
work from Open Firmware. So, I think CRASH_DUMP should just be disabled for
PPC_BOOK3S_32 by default and users who want to use it on these systems, will have to
enable it explicitly.

Adrian

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer
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