On Wed, Jun 14, 2017 at 5:20 AM, <frowand.list@xxxxxxxxx> wrote: > From: Frank Rowand <frank.rowand@xxxxxxxx> > > Add ABI documentation for /sys/firmware/fdt > > Update contact for /sys/firmware/devicetree/* to include mail list > > Signed-off-by: Frank Rowand <frank.rowand@xxxxxxxx> Acked-by: Grant Likely <grant.likely@xxxxxxx> (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 <grant.likely@xxxxxxxxxx> > +Contact: Grant Likely <grant.likely@xxxxxxxxxx>, devicetree@xxxxxxxxxxxxxxx > 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 <frank.rowand@xxxxxxxx>, devicetree@xxxxxxxxxxxxxxx > +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 <frank.rowand@xxxxxxxx> > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
