[PATCH]kdump: pass noefi and acpi_rsdp= to 2nd kernel
khalid at gonehiking.org
Thu Oct 18 10:59:54 EDT 2012
On Thu, 2012-10-18 at 11:12 +0800, Dave Young wrote:
> On 09/12/2012 10:35 AM, Dave Young wrote:
> > On 09/07/2012 04:56 PM, Dave Young wrote:
> >> I did some digging about the efi boot kdump in slackware with kernel
> >> from latest linus tree. I'm surprise that kdump works even without these
> >> "noefi" and "acpi_rsdp="
> >> With fedora 17 3.4.3 kernel passing "acpi_rsdp=" is enough for kdump
> >> kernel booting.
> >> Actually in x86 setup code if bootloader do not pass correct efi_info in
> >> boot_params efi_enabled will be set to 0 automaticlly.
> >> So as for this patch 'noefi' is not needed.
> >> I will do more testing to see why linus tree works without "acpi_rsdp="
> > There's probably some efi changes between 3.4.3 - 3.6.0-rc4 cause this
> > works. I have not got time to bisect it.
> During recent test, I found I mistakenly used wrong kernel config
> without CONFIG_EFI in 1st kernel for testing. acpi_rsdp= is still needed.
> Just resent the v2 patch, please help to review.
I suspect EFI based systems with Compatibility Support Module (CSM) are
still not going to need this, but I can see native EFI systems with no
CSM needing this. I have reviewed your patch.
BTW, I am no longer at HP, so <khalid.aziz at hp.com> is no longer valid.
<khalid at gonehiking.org> is my permanent personal email address.
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