lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20230614063018.2419043-4-miquel.raynal@bootlin.com>
Date:   Wed, 14 Jun 2023 08:30:17 +0200
From:   Miquel Raynal <miquel.raynal@...tlin.com>
To:     Srinivas Kandagatla <srinivas.kandagatla@...aro.org>
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Rafael J . Wysocki" <rafael@...nel.org>,
        <linux-kernel@...r.kernel.org>,
        Thomas Petazzoni <thomas.petazzoni@...tlin.com>,
        Luka Perkov <luka.perkov@...tura.hr>,
        Robert Marko <robert.marko@...tura.hr>,
        Miquel Raynal <miquel.raynal@...tlin.com>
Subject: [PATCH v4 3/4] ABI: sysfs-nvmem-cells: Expose cells through sysfs

The binary content of nvmem devices is available to the user so in the
easiest cases, finding the content of a cell is rather easy as it is
just a matter of looking at a known and fixed offset. However, nvmem
layouts have been recently introduced to cope with more advanced
situations, where the offset and size of the cells is not known in
advance or is dynamic. When using layouts, more advanced parsers are
used by the kernel in order to give direct access to the content of each
cell regardless of their position/size in the underlying device, but
these information were not accessible to the user.

By exposing the nvmem cells to the user through a dedicated cell/ folder
containing one file per cell, we provide a straightforward access to
useful user information without the need for re-writing a userland
parser. Content of nvmem cells is usually: product names, manufacturing
date, MAC addresses, etc,

Signed-off-by: Miquel Raynal <miquel.raynal@...tlin.com>
---
 Documentation/ABI/testing/sysfs-nvmem-cells | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-nvmem-cells

diff --git a/Documentation/ABI/testing/sysfs-nvmem-cells b/Documentation/ABI/testing/sysfs-nvmem-cells
new file mode 100644
index 000000000000..641a7d7dad76
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-nvmem-cells
@@ -0,0 +1,19 @@
+What:		/sys/bus/nvmem/devices/.../cells/<cell-name>
+Date:		May 2023
+KernelVersion:	6.5
+Contact:	Miquel Raynal <miquel.raynal@...tlin.com>
+Description:
+		The cells/ folder contains one file per cell exposed by
+		the nvmem device. The name of the file is the cell name.
+		The length of the file is the size of the cell (when
+		known). The content of the file is the binary content of
+		the cell (may sometimes be ASCII, likely without
+		trailing character).
+		Note: This file is only present if CONFIG_NVMEM_SYSFS
+		is enabled
+
+		ex::
+
+		  hexdump -C /sys/bus/nvmem/devices/1-00563/cells/product-name
+		  00000000  54 4e 34 38 4d 2d 50 2d  44 4e         |TN48M-P-DN|
+		  0000000a
-- 
2.34.1

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ