2020-10-16 04:55:43

by Andrew Jeffery

Subject: [PATCH 2/2] ARM: dts: tacoma: Add reserved memory for ramoops

Reserve a 1.5MiB region of memory to record kmsg dumps, console and
userspace message state into 16kiB ring-buffer slots. The sizing allows
for up to 32 dumps to be captured and read out.

Set max-reason to KMSG_DUMP_EMERG to capture bad-path reboots.

Signed-off-by: Andrew Jeffery <[email protected]>
---
arch/arm/boot/dts/aspeed-bmc-opp-tacoma.dts | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/arch/arm/boot/dts/aspeed-bmc-opp-tacoma.dts b/arch/arm/boot/dts/aspeed-bmc-opp-tacoma.dts
index 46f2f538baba..4f7e9b490e1a 100644
--- a/arch/arm/boot/dts/aspeed-bmc-opp-tacoma.dts
+++ b/arch/arm/boot/dts/aspeed-bmc-opp-tacoma.dts
@@ -26,6 +26,15 @@ reserved-memory {
#size-cells = <1>;
ranges;

+ ramoops@b9e80000 {
+ compatible = "ramoops";
+ reg = <0xb9e80000 0x180000>;
+ record-size = <0x4000>;
+ console-size = <0x4000>;
+ pmsg-size = <0x4000>;
+ max-reason = <3>; /* KMSG_DUMP_EMERG */
+ };
+
flash_memory: region@ba000000 {
no-map;
reg = <0xb8000000 0x4000000>; /* 64M */
--
2.25.1

2020-10-21 12:30:21

by Joel Stanley

Subject: Re: [PATCH 2/2] ARM: dts: tacoma: Add reserved memory for ramoops

On Fri, 16 Oct 2020 at 04:36, Andrew Jeffery <[email protected]> wrote:
>
> Reserve a 1.5MiB region of memory to record kmsg dumps, console and
> userspace message state into 16kiB ring-buffer slots. The sizing allows
> for up to 32 dumps to be captured and read out.
>
> Set max-reason to KMSG_DUMP_EMERG to capture bad-path reboots.
>
> Signed-off-by: Andrew Jeffery <[email protected]>
> ---
> arch/arm/boot/dts/aspeed-bmc-opp-tacoma.dts | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/arch/arm/boot/dts/aspeed-bmc-opp-tacoma.dts b/arch/arm/boot/dts/aspeed-bmc-opp-tacoma.dts
> index 46f2f538baba..4f7e9b490e1a 100644
> --- a/arch/arm/boot/dts/aspeed-bmc-opp-tacoma.dts
> +++ b/arch/arm/boot/dts/aspeed-bmc-opp-tacoma.dts
> @@ -26,6 +26,15 @@ reserved-memory {
> #size-cells = <1>;
> ranges;
>
> + ramoops@b9e80000 {
> + compatible = "ramoops";
> + reg = <0xb9e80000 0x180000>;

I take that r-b back. When booting, we see:

[ 0.000000] region@ba000000 (0xb8000000--0xbc000000) overlaps with
ramoops@b9e80000 (0xb9e80000--0xba000000)

Which appears to be a true statement.

> + record-size = <0x4000>;
> + console-size = <0x4000>;
> + pmsg-size = <0x4000>;
> + max-reason = <3>; /* KMSG_DUMP_EMERG */
> + };
> +
> flash_memory: region@ba000000 {
> no-map;
> reg = <0xb8000000 0x4000000>; /* 64M */
> --
> 2.25.1
>

2020-10-21 12:39:55

by Andrew Jeffery

Subject: Re: [PATCH 2/2] ARM: dts: tacoma: Add reserved memory for ramoops

On Wed, 21 Oct 2020, at 15:35, Joel Stanley wrote:
> On Fri, 16 Oct 2020 at 04:36, Andrew Jeffery <[email protected]> wrote:
> >
> > Reserve a 1.5MiB region of memory to record kmsg dumps, console and
> > userspace message state into 16kiB ring-buffer slots. The sizing allows
> > for up to 32 dumps to be captured and read out.
> >
> > Set max-reason to KMSG_DUMP_EMERG to capture bad-path reboots.
> >
> > Signed-off-by: Andrew Jeffery <[email protected]>
> > ---
> > arch/arm/boot/dts/aspeed-bmc-opp-tacoma.dts | 9 +++++++++
> > 1 file changed, 9 insertions(+)
> >
> > diff --git a/arch/arm/boot/dts/aspeed-bmc-opp-tacoma.dts b/arch/arm/boot/dts/aspeed-bmc-opp-tacoma.dts
> > index 46f2f538baba..4f7e9b490e1a 100644
> > --- a/arch/arm/boot/dts/aspeed-bmc-opp-tacoma.dts
> > +++ b/arch/arm/boot/dts/aspeed-bmc-opp-tacoma.dts
> > @@ -26,6 +26,15 @@ reserved-memory {
> > #size-cells = <1>;
> > ranges;
> >
> > + ramoops@b9e80000 {
> > + compatible = "ramoops";
> > + reg = <0xb9e80000 0x180000>;
>
> I take that r-b back. When booting, we see:
>
> [ 0.000000] region@ba000000 (0xb8000000--0xbc000000) overlaps with
> ramoops@b9e80000 (0xb9e80000--0xba000000)
>
> Which appears to be a true statement.

Yep:

>
> > + record-size = <0x4000>;
> > + console-size = <0x4000>;
> > + pmsg-size = <0x4000>;
> > + max-reason = <3>; /* KMSG_DUMP_EMERG */
> > + };
> > +
> > flash_memory: region@ba000000 {
> > no-map;
> > reg = <0xb8000000 0x4000000>; /* 64M */

Looks like I derived the ramoops address from the flash_memory node label, but
that's mismatched with its reg value.