96 lines
3.6 KiB
Plaintext
96 lines
3.6 KiB
Plaintext
What: /sys/devices/socX
|
||
Date: January 2012
|
||
contact: Lee Jones <lee.jones@linaro.org>
|
||
Description:
|
||
The /sys/devices/ directory contains a sub-directory for each
|
||
System-on-Chip (SoC) device on a running platform. Information
|
||
regarding each SoC can be obtained by reading sysfs files. This
|
||
functionality is only available if implemented by the platform.
|
||
|
||
The directory created for each SoC will also house information
|
||
about devices which are commonly contained in /sys/devices/platform.
|
||
It has been agreed that if an SoC device exists, its supported
|
||
devices would be better suited to appear as children of that SoC.
|
||
|
||
What: /sys/devices/socX/machine
|
||
Date: January 2012
|
||
contact: Lee Jones <lee.jones@linaro.org>
|
||
Description:
|
||
Read-only attribute common to all SoCs. Contains the SoC machine
|
||
name (e.g. Ux500).
|
||
|
||
What: /sys/devices/socX/family
|
||
Date: January 2012
|
||
contact: Lee Jones <lee.jones@linaro.org>
|
||
Description:
|
||
Read-only attribute common to all SoCs. Contains SoC family name
|
||
(e.g. DB8500).
|
||
|
||
On many of ARM based silicon with SMCCC v1.2+ compliant firmware
|
||
this will contain the JEDEC JEP106 manufacturer’s identification
|
||
code. The format is "jep106:XXYY" where XX is identity code and
|
||
YY is continuation code.
|
||
|
||
This manufacturer’s identification code is defined by one
|
||
or more eight (8) bit fields, each consisting of seven (7)
|
||
data bits plus one (1) odd parity bit. It is a single field,
|
||
limiting the possible number of vendors to 126. To expand
|
||
the maximum number of identification codes, a continuation
|
||
scheme has been defined.
|
||
|
||
The specified mechanism is that an identity code of 0x7F
|
||
represents the "continuation code" and implies the presence
|
||
of an additional identity code field, and this mechanism
|
||
may be extended to multiple continuation codes followed
|
||
by the manufacturer's identity code.
|
||
|
||
For example, ARM has identity code 0x7F 0x7F 0x7F 0x7F 0x3B,
|
||
which is code 0x3B on the fifth 'page'. This is shortened
|
||
as JEP106 identity code of 0x3B and a continuation code of
|
||
0x4 to represent the four continuation codes preceding the
|
||
identity code.
|
||
|
||
What: /sys/devices/socX/serial_number
|
||
Date: January 2019
|
||
contact: Bjorn Andersson <bjorn.andersson@linaro.org>
|
||
Description:
|
||
Read-only attribute supported by most SoCs. Contains the SoC's
|
||
serial number, if available.
|
||
|
||
What: /sys/devices/socX/soc_id
|
||
Date: January 2012
|
||
contact: Lee Jones <lee.jones@linaro.org>
|
||
Description:
|
||
Read-only attribute supported by most SoCs. In the case of
|
||
ST-Ericsson's chips this contains the SoC serial number.
|
||
|
||
On many of ARM based silicon with SMCCC v1.2+ compliant firmware
|
||
this will contain the SOC ID appended to the family attribute
|
||
to ensure there is no conflict in this namespace across various
|
||
vendors. The format is "jep106:XXYY:ZZZZ" where XX is identity
|
||
code, YY is continuation code and ZZZZ is the SOC ID.
|
||
|
||
What: /sys/devices/socX/revision
|
||
Date: January 2012
|
||
contact: Lee Jones <lee.jones@linaro.org>
|
||
Description:
|
||
Read-only attribute supported by most SoCs. Contains the SoC's
|
||
manufacturing revision number.
|
||
|
||
What: /sys/devices/socX/process
|
||
Date: January 2012
|
||
contact: Lee Jones <lee.jones@linaro.org>
|
||
Description:
|
||
Read-only attribute supported ST-Ericsson's silicon. Contains the
|
||
the process by which the silicon chip was manufactured.
|
||
|
||
What: /sys/bus/soc
|
||
Date: January 2012
|
||
contact: Lee Jones <lee.jones@linaro.org>
|
||
Description:
|
||
The /sys/bus/soc/ directory contains the usual sub-folders
|
||
expected under most buses. /sys/bus/soc/devices is of particular
|
||
interest, as it contains a symlink for each SoC device found on
|
||
the system. Each symlink points back into the aforementioned
|
||
/sys/devices/socX devices.
|