2017-06-14 04:21:04

by Frank Rowand

[permalink] [raw]
Subject: [PATCH] of: document /sys/firmware/fdt

From: Frank Rowand <[email protected]>

Add ABI documentation for /sys/firmware/fdt

Update contact for /sys/firmware/devicetree/* to include mail list

Signed-off-by: Frank Rowand <[email protected]>
---
Documentation/ABI/testing/sysfs-firmware-ofw | 27 ++++++++++++++++++++++++++-
1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/Documentation/ABI/testing/sysfs-firmware-ofw b/Documentation/ABI/testing/sysfs-firmware-ofw
index f562b188e71d..8e700db6c295 100644
--- a/Documentation/ABI/testing/sysfs-firmware-ofw
+++ b/Documentation/ABI/testing/sysfs-firmware-ofw
@@ -1,6 +1,6 @@
What: /sys/firmware/devicetree/*
Date: November 2013
-Contact: Grant Likely <[email protected]>
+Contact: Grant Likely <[email protected]>, [email protected]
Description:
When using OpenFirmware or a Flattened Device Tree to enumerate
hardware, the device tree structure will be exposed in this
@@ -26,3 +26,28 @@ Description:
name plus address). Properties are represented as files
in the directory. The contents of each file is the exact
binary data from the device tree.
+
+What: /sys/firmware/fdt
+Date: February 2015
+KernelVersion: 3.19
+Contact: Frank Rowand <[email protected]>, [email protected]
+Description:
+ Exports the FDT blob that was passed to the kernel by
+ the bootloader. This allows userland applications such
+ as kexec to access the raw binary. This blob is also
+ useful when debugging since it contains any changes
+ made to the blob by the bootloader.
+
+ The fact that this node does not reside under
+ /sys/firmware/device-tree is deliberate: FDT is also used
+ on arm64 UEFI/ACPI systems to communicate just the UEFI
+ and ACPI entry points, but the FDT is never unflattened
+ and used to configure the system.
+
+ A CRC32 checksum is calculated over the entire FDT
+ blob, and verified at late_initcall time. The sysfs
+ entry is instantiated only if the checksum is valid,
+ i.e., if the FDT blob has not been modified in the mean
+ time. Otherwise, a warning is printed.
+Users: kexec, debugging
+
--
Frank Rowand <[email protected]>


2017-06-14 09:56:18

by Mark Rutland

[permalink] [raw]
Subject: Re: [PATCH] of: document /sys/firmware/fdt

[Adding Ard, as he added /sys/firmware/fdt]

On Tue, Jun 13, 2017 at 09:20:07PM -0700, [email protected] wrote:
> From: Frank Rowand <[email protected]>
>
> Add ABI documentation for /sys/firmware/fdt
>
> Update contact for /sys/firmware/devicetree/* to include mail list
>
> Signed-off-by: Frank Rowand <[email protected]>

FWIW:

Acked-by: Mark Rutland <[email protected]>

Mark.

> ---
> Documentation/ABI/testing/sysfs-firmware-ofw | 27 ++++++++++++++++++++++++++-
> 1 file changed, 26 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/ABI/testing/sysfs-firmware-ofw b/Documentation/ABI/testing/sysfs-firmware-ofw
> index f562b188e71d..8e700db6c295 100644
> --- a/Documentation/ABI/testing/sysfs-firmware-ofw
> +++ b/Documentation/ABI/testing/sysfs-firmware-ofw
> @@ -1,6 +1,6 @@
> What: /sys/firmware/devicetree/*
> Date: November 2013
> -Contact: Grant Likely <[email protected]>
> +Contact: Grant Likely <[email protected]>, [email protected]
> Description:
> When using OpenFirmware or a Flattened Device Tree to enumerate
> hardware, the device tree structure will be exposed in this
> @@ -26,3 +26,28 @@ Description:
> name plus address). Properties are represented as files
> in the directory. The contents of each file is the exact
> binary data from the device tree.
> +
> +What: /sys/firmware/fdt
> +Date: February 2015
> +KernelVersion: 3.19
> +Contact: Frank Rowand <[email protected]>, [email protected]
> +Description:
> + Exports the FDT blob that was passed to the kernel by
> + the bootloader. This allows userland applications such
> + as kexec to access the raw binary. This blob is also
> + useful when debugging since it contains any changes
> + made to the blob by the bootloader.
> +
> + The fact that this node does not reside under
> + /sys/firmware/device-tree is deliberate: FDT is also used
> + on arm64 UEFI/ACPI systems to communicate just the UEFI
> + and ACPI entry points, but the FDT is never unflattened
> + and used to configure the system.
> +
> + A CRC32 checksum is calculated over the entire FDT
> + blob, and verified at late_initcall time. The sysfs
> + entry is instantiated only if the checksum is valid,
> + i.e., if the FDT blob has not been modified in the mean
> + time. Otherwise, a warning is printed.
> +Users: kexec, debugging
> +
> --
> Frank Rowand <[email protected]>
>
> --
> To unsubscribe from this list: send the line "unsubscribe devicetree" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.

2017-06-14 10:16:57

by Ard Biesheuvel

[permalink] [raw]
Subject: Re: [PATCH] of: document /sys/firmware/fdt

On 14 June 2017 at 11:55, Mark Rutland <[email protected]> wrote:
> [Adding Ard, as he added /sys/firmware/fdt]
>

Thanks

> On Tue, Jun 13, 2017 at 09:20:07PM -0700, [email protected] wrote:
>> From: Frank Rowand <[email protected]>
>>
>> Add ABI documentation for /sys/firmware/fdt
>>
>> Update contact for /sys/firmware/devicetree/* to include mail list
>>
>> Signed-off-by: Frank Rowand <[email protected]>
>
> FWIW:
>
> Acked-by: Mark Rutland <[email protected]>
>

Reviewed-by: Ard Biesheuvel <[email protected]>

>> ---
>> Documentation/ABI/testing/sysfs-firmware-ofw | 27 ++++++++++++++++++++++++++-
>> 1 file changed, 26 insertions(+), 1 deletion(-)
>>
>> diff --git a/Documentation/ABI/testing/sysfs-firmware-ofw b/Documentation/ABI/testing/sysfs-firmware-ofw
>> index f562b188e71d..8e700db6c295 100644
>> --- a/Documentation/ABI/testing/sysfs-firmware-ofw
>> +++ b/Documentation/ABI/testing/sysfs-firmware-ofw
>> @@ -1,6 +1,6 @@
>> What: /sys/firmware/devicetree/*
>> Date: November 2013
>> -Contact: Grant Likely <[email protected]>
>> +Contact: Grant Likely <[email protected]>, [email protected]
>> Description:
>> When using OpenFirmware or a Flattened Device Tree to enumerate
>> hardware, the device tree structure will be exposed in this
>> @@ -26,3 +26,28 @@ Description:
>> name plus address). Properties are represented as files
>> in the directory. The contents of each file is the exact
>> binary data from the device tree.
>> +
>> +What: /sys/firmware/fdt
>> +Date: February 2015
>> +KernelVersion: 3.19
>> +Contact: Frank Rowand <[email protected]>, [email protected]
>> +Description:
>> + Exports the FDT blob that was passed to the kernel by
>> + the bootloader. This allows userland applications such
>> + as kexec to access the raw binary. This blob is also
>> + useful when debugging since it contains any changes
>> + made to the blob by the bootloader.
>> +
>> + The fact that this node does not reside under
>> + /sys/firmware/device-tree is deliberate: FDT is also used
>> + on arm64 UEFI/ACPI systems to communicate just the UEFI
>> + and ACPI entry points, but the FDT is never unflattened
>> + and used to configure the system.
>> +
>> + A CRC32 checksum is calculated over the entire FDT
>> + blob, and verified at late_initcall time. The sysfs
>> + entry is instantiated only if the checksum is valid,
>> + i.e., if the FDT blob has not been modified in the mean
>> + time. Otherwise, a warning is printed.
>> +Users: kexec, debugging
>> +
>> --
>> Frank Rowand <[email protected]>
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe devicetree" in
>> the body of a message to [email protected]
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
> IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.

2017-06-22 15:21:28

by Rob Herring (Arm)

[permalink] [raw]
Subject: Re: [PATCH] of: document /sys/firmware/fdt

On Tue, Jun 13, 2017 at 09:20:07PM -0700, [email protected] wrote:
> From: Frank Rowand <[email protected]>
>
> Add ABI documentation for /sys/firmware/fdt
>
> Update contact for /sys/firmware/devicetree/* to include mail list
>
> Signed-off-by: Frank Rowand <[email protected]>
> ---
> Documentation/ABI/testing/sysfs-firmware-ofw | 27 ++++++++++++++++++++++++++-
> 1 file changed, 26 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/ABI/testing/sysfs-firmware-ofw b/Documentation/ABI/testing/sysfs-firmware-ofw
> index f562b188e71d..8e700db6c295 100644
> --- a/Documentation/ABI/testing/sysfs-firmware-ofw
> +++ b/Documentation/ABI/testing/sysfs-firmware-ofw
> @@ -1,6 +1,6 @@
> What: /sys/firmware/devicetree/*
> Date: November 2013
> -Contact: Grant Likely <[email protected]>
> +Contact: Grant Likely <[email protected]>, [email protected]

Grant's email is not valid either. I would just drop it unless he wants
his secretlab.ca email.

Rob

2017-06-22 15:23:33

by Rob Herring (Arm)

[permalink] [raw]
Subject: Re: [PATCH] of: document /sys/firmware/fdt

Meant to add Grant.

On Thu, Jun 22, 2017 at 10:21:24AM -0500, Rob Herring wrote:
> On Tue, Jun 13, 2017 at 09:20:07PM -0700, [email protected] wrote:
> > From: Frank Rowand <[email protected]>
> >
> > Add ABI documentation for /sys/firmware/fdt
> >
> > Update contact for /sys/firmware/devicetree/* to include mail list
> >
> > Signed-off-by: Frank Rowand <[email protected]>
> > ---
> > Documentation/ABI/testing/sysfs-firmware-ofw | 27 ++++++++++++++++++++++++++-
> > 1 file changed, 26 insertions(+), 1 deletion(-)
> >
> > diff --git a/Documentation/ABI/testing/sysfs-firmware-ofw b/Documentation/ABI/testing/sysfs-firmware-ofw
> > index f562b188e71d..8e700db6c295 100644
> > --- a/Documentation/ABI/testing/sysfs-firmware-ofw
> > +++ b/Documentation/ABI/testing/sysfs-firmware-ofw
> > @@ -1,6 +1,6 @@
> > What: /sys/firmware/devicetree/*
> > Date: November 2013
> > -Contact: Grant Likely <[email protected]>
> > +Contact: Grant Likely <[email protected]>, [email protected]
>
> Grant's email is not valid either. I would just drop it unless he wants
> his secretlab.ca email.
>
> Rob

2017-06-28 21:47:00

by Frank Rowand

[permalink] [raw]
Subject: Re: [PATCH] of: document /sys/firmware/fdt

On 06/22/17 08:23, Rob Herring wrote:
> Meant to add Grant.
>
> On Thu, Jun 22, 2017 at 10:21:24AM -0500, Rob Herring wrote:
>> On Tue, Jun 13, 2017 at 09:20:07PM -0700, [email protected] wrote:
>>> From: Frank Rowand <[email protected]>
>>>
>>> Add ABI documentation for /sys/firmware/fdt
>>>
>>> Update contact for /sys/firmware/devicetree/* to include mail list
>>>
>>> Signed-off-by: Frank Rowand <[email protected]>
>>> ---
>>> Documentation/ABI/testing/sysfs-firmware-ofw | 27 ++++++++++++++++++++++++++-
>>> 1 file changed, 26 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/Documentation/ABI/testing/sysfs-firmware-ofw b/Documentation/ABI/testing/sysfs-firmware-ofw
>>> index f562b188e71d..8e700db6c295 100644
>>> --- a/Documentation/ABI/testing/sysfs-firmware-ofw
>>> +++ b/Documentation/ABI/testing/sysfs-firmware-ofw
>>> @@ -1,6 +1,6 @@
>>> What: /sys/firmware/devicetree/*
>>> Date: November 2013
>>> -Contact: Grant Likely <[email protected]>
>>> +Contact: Grant Likely <[email protected]>, [email protected]
>>
>> Grant's email is not valid either. I would just drop it unless he wants
>> his secretlab.ca email.
>>
>> Rob
>

No response from Grant, so I'll drop his email and add the mail list.

Also, for the newly added section I'll change the contact from being both
me and the mail list to just be the mail list.

-Frank

2017-06-28 21:49:56

by Grant Likely

[permalink] [raw]
Subject: Re: [PATCH] of: document /sys/firmware/fdt

I'm slowly getting back into things and plan to actively participate.
Please use my ARM address:

[email protected]

g.

On Wed, Jun 28, 2017 at 10:46 PM, Frank Rowand <[email protected]> wrote:
> On 06/22/17 08:23, Rob Herring wrote:
>> Meant to add Grant.
>>
>> On Thu, Jun 22, 2017 at 10:21:24AM -0500, Rob Herring wrote:
>>> On Tue, Jun 13, 2017 at 09:20:07PM -0700, [email protected] wrote:
>>>> From: Frank Rowand <[email protected]>
>>>>
>>>> Add ABI documentation for /sys/firmware/fdt
>>>>
>>>> Update contact for /sys/firmware/devicetree/* to include mail list
>>>>
>>>> Signed-off-by: Frank Rowand <[email protected]>
>>>> ---
>>>> Documentation/ABI/testing/sysfs-firmware-ofw | 27 ++++++++++++++++++++++++++-
>>>> 1 file changed, 26 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/Documentation/ABI/testing/sysfs-firmware-ofw b/Documentation/ABI/testing/sysfs-firmware-ofw
>>>> index f562b188e71d..8e700db6c295 100644
>>>> --- a/Documentation/ABI/testing/sysfs-firmware-ofw
>>>> +++ b/Documentation/ABI/testing/sysfs-firmware-ofw
>>>> @@ -1,6 +1,6 @@
>>>> What: /sys/firmware/devicetree/*
>>>> Date: November 2013
>>>> -Contact: Grant Likely <[email protected]>
>>>> +Contact: Grant Likely <[email protected]>, [email protected]
>>>
>>> Grant's email is not valid either. I would just drop it unless he wants
>>> his secretlab.ca email.
>>>
>>> Rob
>>
>
> No response from Grant, so I'll drop his email and add the mail list.
>
> Also, for the newly added section I'll change the contact from being both
> me and the mail list to just be the mail list.
>
> -Frank

2017-06-28 22:04:35

by Frank Rowand

[permalink] [raw]
Subject: Re: [PATCH] of: document /sys/firmware/fdt

On 06/28/17 14:49, Grant Likely wrote:
> I'm slowly getting back into things and plan to actively participate.
> Please use my ARM address:
>
> [email protected]

OK, I'll do that.

-Frank

>
> g.
>
> On Wed, Jun 28, 2017 at 10:46 PM, Frank Rowand <[email protected]> wrote:
>> On 06/22/17 08:23, Rob Herring wrote:
>>> Meant to add Grant.
>>>
>>> On Thu, Jun 22, 2017 at 10:21:24AM -0500, Rob Herring wrote:
>>>> On Tue, Jun 13, 2017 at 09:20:07PM -0700, [email protected] wrote:
>>>>> From: Frank Rowand <[email protected]>
>>>>>
>>>>> Add ABI documentation for /sys/firmware/fdt
>>>>>
>>>>> Update contact for /sys/firmware/devicetree/* to include mail list
>>>>>
>>>>> Signed-off-by: Frank Rowand <[email protected]>
>>>>> ---
>>>>> Documentation/ABI/testing/sysfs-firmware-ofw | 27 ++++++++++++++++++++++++++-
>>>>> 1 file changed, 26 insertions(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/Documentation/ABI/testing/sysfs-firmware-ofw b/Documentation/ABI/testing/sysfs-firmware-ofw
>>>>> index f562b188e71d..8e700db6c295 100644
>>>>> --- a/Documentation/ABI/testing/sysfs-firmware-ofw
>>>>> +++ b/Documentation/ABI/testing/sysfs-firmware-ofw
>>>>> @@ -1,6 +1,6 @@
>>>>> What: /sys/firmware/devicetree/*
>>>>> Date: November 2013
>>>>> -Contact: Grant Likely <[email protected]>
>>>>> +Contact: Grant Likely <[email protected]>, [email protected]
>>>>
>>>> Grant's email is not valid either. I would just drop it unless he wants
>>>> his secretlab.ca email.
>>>>
>>>> Rob
>>>
>>
>> No response from Grant, so I'll drop his email and add the mail list.
>>
>> Also, for the newly added section I'll change the contact from being both
>> me and the mail list to just be the mail list.
>>
>> -Frank
>

2017-06-29 13:29:10

by Grant Likely

[permalink] [raw]
Subject: Re: [PATCH] of: document /sys/firmware/fdt

On Wed, Jun 14, 2017 at 5:20 AM, <[email protected]> wrote:
> From: Frank Rowand <[email protected]>
>
> Add ABI documentation for /sys/firmware/fdt
>
> Update contact for /sys/firmware/devicetree/* to include mail list
>
> Signed-off-by: Frank Rowand <[email protected]>

Acked-by: Grant Likely <[email protected]>

(Apologies for acking from a different address. My ARM email isn't yet
set up to play nice on mailing lists.)

g.

> ---
> Documentation/ABI/testing/sysfs-firmware-ofw | 27 ++++++++++++++++++++++++++-
> 1 file changed, 26 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/ABI/testing/sysfs-firmware-ofw b/Documentation/ABI/testing/sysfs-firmware-ofw
> index f562b188e71d..8e700db6c295 100644
> --- a/Documentation/ABI/testing/sysfs-firmware-ofw
> +++ b/Documentation/ABI/testing/sysfs-firmware-ofw
> @@ -1,6 +1,6 @@
> What: /sys/firmware/devicetree/*
> Date: November 2013
> -Contact: Grant Likely <[email protected]>
> +Contact: Grant Likely <[email protected]>, [email protected]
> Description:
> When using OpenFirmware or a Flattened Device Tree to enumerate
> hardware, the device tree structure will be exposed in this
> @@ -26,3 +26,28 @@ Description:
> name plus address). Properties are represented as files
> in the directory. The contents of each file is the exact
> binary data from the device tree.
> +
> +What: /sys/firmware/fdt
> +Date: February 2015
> +KernelVersion: 3.19
> +Contact: Frank Rowand <[email protected]>, [email protected]
> +Description:
> + Exports the FDT blob that was passed to the kernel by
> + the bootloader. This allows userland applications such
> + as kexec to access the raw binary. This blob is also
> + useful when debugging since it contains any changes
> + made to the blob by the bootloader.
> +
> + The fact that this node does not reside under
> + /sys/firmware/device-tree is deliberate: FDT is also used
> + on arm64 UEFI/ACPI systems to communicate just the UEFI
> + and ACPI entry points, but the FDT is never unflattened
> + and used to configure the system.
> +
> + A CRC32 checksum is calculated over the entire FDT
> + blob, and verified at late_initcall time. The sysfs
> + entry is instantiated only if the checksum is valid,
> + i.e., if the FDT blob has not been modified in the mean
> + time. Otherwise, a warning is printed.
> +Users: kexec, debugging
> +
> --
> Frank Rowand <[email protected]>
>