diff mbox

arm64: Add CMDLINE_EXTEND

Message ID 61060b44-64a9-d628-4faf-3a7ae06048aa@infradead.org (mailing list archive)
State New, archived
Headers show

Commit Message

Geoff Levand Dec. 2, 2016, 10:17 p.m. UTC
The device tree code already supports CMDLINE_EXTEND,
so add the config option to make it available on arm64.

Signed-off-by: Geoff Levand <geoff@infradead.org>
---
 arch/arm64/Kconfig | 6 ++++++
 1 file changed, 6 insertions(+)

Comments

Catalin Marinas Dec. 5, 2016, 12:08 p.m. UTC | #1
Hi Geoff,

On Fri, Dec 02, 2016 at 02:17:02PM -0800, Geoff Levand wrote:
> The device tree code already supports CMDLINE_EXTEND,
> so add the config option to make it available on arm64.

What's your use-case for this patch? Note that both CMDLINE_FORCE and
CMDLINE_EXTEND (if we introduce it) are ignored by the EFI stub.
However, we don't seem to have stated this anywhere.
Geoff Levand Dec. 5, 2016, 5:41 p.m. UTC | #2
Hi Catalin,

On 12/05/2016 04:08 AM, Catalin Marinas wrote:
> On Fri, Dec 02, 2016 at 02:17:02PM -0800, Geoff Levand wrote:
>> The device tree code already supports CMDLINE_EXTEND,
>> so add the config option to make it available on arm64.
> 
> What's your use-case for this patch? Note that both CMDLINE_FORCE and
> CMDLINE_EXTEND (if we introduce it) are ignored by the EFI stub.
> However, we don't seem to have stated this anywhere.

I use this in CoreOS, where we need to set "acpi=force" for
arm64.  CoreOS uses a proper UEFI + grub.

See: 

  https://github.com/coreos/scripts/pull/610
  https://github.com/coreos/coreos-overlay/pull/2298

I can add a comment for EFI stub, either in the Kconfig
options, and/or in Documentation/efi-stub.txt.  Just let
me know.

-Geoff
Will Deacon Dec. 6, 2016, 12:20 p.m. UTC | #3
On Mon, Dec 05, 2016 at 09:41:06AM -0800, Geoff Levand wrote:
> On 12/05/2016 04:08 AM, Catalin Marinas wrote:
> > On Fri, Dec 02, 2016 at 02:17:02PM -0800, Geoff Levand wrote:
> >> The device tree code already supports CMDLINE_EXTEND,
> >> so add the config option to make it available on arm64.
> > 
> > What's your use-case for this patch? Note that both CMDLINE_FORCE and
> > CMDLINE_EXTEND (if we introduce it) are ignored by the EFI stub.
> > However, we don't seem to have stated this anywhere.
> 
> I use this in CoreOS, where we need to set "acpi=force" for
> arm64.  CoreOS uses a proper UEFI + grub.

So why can't you just set that in grub if you want to boot with ACPI?

Will
Geoff Levand Dec. 6, 2016, 6:28 p.m. UTC | #4
Hi Will,

On 12/06/2016 04:20 AM, Will Deacon wrote:
> On Mon, Dec 05, 2016 at 09:41:06AM -0800, Geoff Levand wrote:
>> On 12/05/2016 04:08 AM, Catalin Marinas wrote:
>>> On Fri, Dec 02, 2016 at 02:17:02PM -0800, Geoff Levand wrote:
>>>> The device tree code already supports CMDLINE_EXTEND,
>>>> so add the config option to make it available on arm64.
>>>
>>> What's your use-case for this patch? Note that both CMDLINE_FORCE and
>>> CMDLINE_EXTEND (if we introduce it) are ignored by the EFI stub.
>>> However, we don't seem to have stated this anywhere.
>>
>> I use this in CoreOS, where we need to set "acpi=force" for
>> arm64.  CoreOS uses a proper UEFI + grub.
> 
> So why can't you just set that in grub if you want to boot with ACPI?

That is how I originally did it, but it was suggested I
do it in the kernel config.  See:

  https://github.com/coreos/scripts/pull/610

Is there any reason why we don't want arm64 to have
CMDLINE_EXTEND?

-Geoff
Will Deacon Dec. 6, 2016, 7:03 p.m. UTC | #5
On Tue, Dec 06, 2016 at 10:28:19AM -0800, Geoff Levand wrote:
> On 12/06/2016 04:20 AM, Will Deacon wrote:
> > On Mon, Dec 05, 2016 at 09:41:06AM -0800, Geoff Levand wrote:
> >> On 12/05/2016 04:08 AM, Catalin Marinas wrote:
> >>> On Fri, Dec 02, 2016 at 02:17:02PM -0800, Geoff Levand wrote:
> >>>> The device tree code already supports CMDLINE_EXTEND,
> >>>> so add the config option to make it available on arm64.
> >>>
> >>> What's your use-case for this patch? Note that both CMDLINE_FORCE and
> >>> CMDLINE_EXTEND (if we introduce it) are ignored by the EFI stub.
> >>> However, we don't seem to have stated this anywhere.
> >>
> >> I use this in CoreOS, where we need to set "acpi=force" for
> >> arm64.  CoreOS uses a proper UEFI + grub.
> > 
> > So why can't you just set that in grub if you want to boot with ACPI?
> 
> That is how I originally did it, but it was suggested I
> do it in the kernel config.  See:
> 
>   https://github.com/coreos/scripts/pull/610
> 
> Is there any reason why we don't want arm64 to have
> CMDLINE_EXTEND?

I'm yet to see a good use-case for it.

Will
diff mbox

Patch

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 969ef88..51f7545 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -949,6 +949,12 @@  config CMDLINE
 	  entering them here. As a minimum, you should specify the the
 	  root device (e.g. root=/dev/nfs).
 
+config CMDLINE_EXTEND
+	bool "Extend bootloader kernel arguments"
+	help
+	  The command-line arguments provided by the boot loader will be
+	  appended to the default kernel command string.
+
 config CMDLINE_FORCE
 	bool "Always use the default kernel command string"
 	help