[PATCH] ARM: tegra: add kexec support to defconfig

[PATCH] ARM: tegra: add kexec support to defconfig

[Stephen Warren]

From: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>

Signed-off-by: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
---
 arch/arm/configs/tegra_defconfig |    1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/tegra_defconfig b/arch/arm/configs/tegra_defconfig
index 742dc41..e621603 100644
--- a/arch/arm/configs/tegra_defconfig
+++ b/arch/arm/configs/tegra_defconfig
@@ -34,6 +34,7 @@ CONFIG_AEABI=y
 CONFIG_HIGHMEM=y
 CONFIG_ZBOOT_ROM_TEXT=0x0
 CONFIG_ZBOOT_ROM_BSS=0x0
+CONFIG_KEXEC=y
 CONFIG_CPU_FREQ=y
 CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND=y
 CONFIG_CPU_IDLE=y
-- 
1.7.10.4

Re: [PATCH] ARM: tegra: add kexec support to defconfig

[Stephen Warren]

On 01/02/2013 02:12 PM, Stephen Warren wrote:
>...

Applied to (squashed into) Tegra's for-3.9/defconfig branch.

Re: [PATCH] ARM: tegra: add kexec support to defconfig

[Thierry Reding]

[-- Attachment #1: Type: text/plain, Size: 809 bytes --]

On Wed, Jan 02, 2013 at 02:12:21PM -0700, Stephen Warren wrote:
> From: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> 
> Signed-off-by: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> ---
>  arch/arm/configs/tegra_defconfig |    1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/arm/configs/tegra_defconfig b/arch/arm/configs/tegra_defconfig
> index 742dc41..e621603 100644
> --- a/arch/arm/configs/tegra_defconfig
> +++ b/arch/arm/configs/tegra_defconfig
> @@ -34,6 +34,7 @@ CONFIG_AEABI=y
>  CONFIG_HIGHMEM=y
>  CONFIG_ZBOOT_ROM_TEXT=0x0
>  CONFIG_ZBOOT_ROM_BSS=0x0
> +CONFIG_KEXEC=y
>  CONFIG_CPU_FREQ=y
>  CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND=y
>  CONFIG_CPU_IDLE=y

Interesting. What do you plan to use this for? kdump?

Thierry

[-- Attachment #2: Type: application/pgp-signature, Size: 836 bytes --]

Re: [PATCH] ARM: tegra: add kexec support to defconfig

[Stephen Warren]

On 01/03/2013 02:05 PM, Thierry Reding wrote:
> On Wed, Jan 02, 2013 at 02:12:21PM -0700, Stephen Warren wrote:
>> From: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
>> 
>> Signed-off-by: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> --- 
>> arch/arm/configs/tegra_defconfig |    1 + 1 file changed, 1
>> insertion(+)
>> 
>> diff --git a/arch/arm/configs/tegra_defconfig
>> b/arch/arm/configs/tegra_defconfig index 742dc41..e621603 100644 
>> --- a/arch/arm/configs/tegra_defconfig +++
>> b/arch/arm/configs/tegra_defconfig @@ -34,6 +34,7 @@
>> CONFIG_AEABI=y CONFIG_HIGHMEM=y CONFIG_ZBOOT_ROM_TEXT=0x0 
>> CONFIG_ZBOOT_ROM_BSS=0x0 +CONFIG_KEXEC=y CONFIG_CPU_FREQ=y 
>> CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND=y CONFIG_CPU_IDLE=y
> 
> Interesting. What do you plan to use this for? kdump?

I plan to burn a kernel (and a small stub, and a DTB) into flash
instead of U-Boot, and hence not have to rely on any bootloader.

Even ignoring that, a quick scp of a new kernel to a target followed
by a kexec is faster than rebooting all the way through U-Boot's
slower Ethernet support to boot a new kernel.

Re: [PATCH] ARM: tegra: add kexec support to defconfig

[Thierry Reding]

[-- Attachment #1: Type: text/plain, Size: 1531 bytes --]

On Thu, Jan 03, 2013 at 02:18:27PM -0700, Stephen Warren wrote:
> On 01/03/2013 02:05 PM, Thierry Reding wrote:
> > On Wed, Jan 02, 2013 at 02:12:21PM -0700, Stephen Warren wrote:
> >> From: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> >> 
> >> Signed-off-by: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> --- 
> >> arch/arm/configs/tegra_defconfig |    1 + 1 file changed, 1
> >> insertion(+)
> >> 
> >> diff --git a/arch/arm/configs/tegra_defconfig
> >> b/arch/arm/configs/tegra_defconfig index 742dc41..e621603 100644 
> >> --- a/arch/arm/configs/tegra_defconfig +++
> >> b/arch/arm/configs/tegra_defconfig @@ -34,6 +34,7 @@
> >> CONFIG_AEABI=y CONFIG_HIGHMEM=y CONFIG_ZBOOT_ROM_TEXT=0x0 
> >> CONFIG_ZBOOT_ROM_BSS=0x0 +CONFIG_KEXEC=y CONFIG_CPU_FREQ=y 
> >> CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND=y CONFIG_CPU_IDLE=y
> > 
> > Interesting. What do you plan to use this for? kdump?
> 
> I plan to burn a kernel (and a small stub, and a DTB) into flash
> instead of U-Boot, and hence not have to rely on any bootloader.

Why does that require kexec support?

> Even ignoring that, a quick scp of a new kernel to a target followed
> by a kexec is faster than rebooting all the way through U-Boot's
> slower Ethernet support to boot a new kernel.

That sounds like an interesting approach. I wonder if this actually
works with the current state of drivers in mainline. Sounds like this
could speed up development quite a bit by avoiding full reboots.

Thierry

[-- Attachment #2: Type: application/pgp-signature, Size: 836 bytes --]

Re: [PATCH] ARM: tegra: add kexec support to defconfig

[Stephen Warren]

On 01/03/2013 02:29 PM, Thierry Reding wrote:
> On Thu, Jan 03, 2013 at 02:18:27PM -0700, Stephen Warren wrote:
>> On 01/03/2013 02:05 PM, Thierry Reding wrote:
>>> On Wed, Jan 02, 2013 at 02:12:21PM -0700, Stephen Warren
>>> wrote:
>>>> From: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
>>>> 
>>>> Signed-off-by: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> --- 
>>>> arch/arm/configs/tegra_defconfig |    1 + 1 file changed, 1 
>>>> insertion(+)
>>>> 
>>>> diff --git a/arch/arm/configs/tegra_defconfig 
>>>> b/arch/arm/configs/tegra_defconfig index 742dc41..e621603
>>>> 100644 --- a/arch/arm/configs/tegra_defconfig +++ 
>>>> b/arch/arm/configs/tegra_defconfig @@ -34,6 +34,7 @@ 
>>>> CONFIG_AEABI=y CONFIG_HIGHMEM=y CONFIG_ZBOOT_ROM_TEXT=0x0 
>>>> CONFIG_ZBOOT_ROM_BSS=0x0 +CONFIG_KEXEC=y CONFIG_CPU_FREQ=y 
>>>> CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND=y CONFIG_CPU_IDLE=y
>>> 
>>> Interesting. What do you plan to use this for? kdump?
>> 
>> I plan to burn a kernel (and a small stub, and a DTB) into flash 
>> instead of U-Boot, and hence not have to rely on any bootloader.
> 
> Why does that require kexec support?

Because I'd be using that kernel plus an initrd to download the "real"
kernel over e.g. TFTP and kexec it.

Re: [PATCH] ARM: tegra: add kexec support to defconfig

[Thierry Reding]

[-- Attachment #1: Type: text/plain, Size: 1481 bytes --]

On Thu, Jan 03, 2013 at 02:45:02PM -0700, Stephen Warren wrote:
> On 01/03/2013 02:29 PM, Thierry Reding wrote:
> > On Thu, Jan 03, 2013 at 02:18:27PM -0700, Stephen Warren wrote:
> >> On 01/03/2013 02:05 PM, Thierry Reding wrote:
> >>> On Wed, Jan 02, 2013 at 02:12:21PM -0700, Stephen Warren
> >>> wrote:
> >>>> From: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> >>>> 
> >>>> Signed-off-by: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> --- 
> >>>> arch/arm/configs/tegra_defconfig |    1 + 1 file changed, 1 
> >>>> insertion(+)
> >>>> 
> >>>> diff --git a/arch/arm/configs/tegra_defconfig 
> >>>> b/arch/arm/configs/tegra_defconfig index 742dc41..e621603
> >>>> 100644 --- a/arch/arm/configs/tegra_defconfig +++ 
> >>>> b/arch/arm/configs/tegra_defconfig @@ -34,6 +34,7 @@ 
> >>>> CONFIG_AEABI=y CONFIG_HIGHMEM=y CONFIG_ZBOOT_ROM_TEXT=0x0 
> >>>> CONFIG_ZBOOT_ROM_BSS=0x0 +CONFIG_KEXEC=y CONFIG_CPU_FREQ=y 
> >>>> CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND=y CONFIG_CPU_IDLE=y
> >>> 
> >>> Interesting. What do you plan to use this for? kdump?
> >> 
> >> I plan to burn a kernel (and a small stub, and a DTB) into flash 
> >> instead of U-Boot, and hence not have to rely on any bootloader.
> > 
> > Why does that require kexec support?
> 
> Because I'd be using that kernel plus an initrd to download the "real"
> kernel over e.g. TFTP and kexec it.

Right, that makes sense. Thanks for explaining.

Thierry

[-- Attachment #2: Type: application/pgp-signature, Size: 836 bytes --]