diff options
Diffstat (limited to 'Documentation/admin-guide')
| -rw-r--r-- | Documentation/admin-guide/acpi/ssdt-overlays.rst | 49 | ||||
| -rw-r--r-- | Documentation/admin-guide/bootconfig.rst | 39 | ||||
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 5 |
3 files changed, 68 insertions, 25 deletions
diff --git a/Documentation/admin-guide/acpi/ssdt-overlays.rst b/Documentation/admin-guide/acpi/ssdt-overlays.rst index 5d7e25988085..b5fbf54dca19 100644 --- a/Documentation/admin-guide/acpi/ssdt-overlays.rst +++ b/Documentation/admin-guide/acpi/ssdt-overlays.rst @@ -30,22 +30,21 @@ following ASL code can be used:: { Device (STAC) { - Name (_ADR, Zero) Name (_HID, "BMA222E") + Name (RBUF, ResourceTemplate () + { + I2cSerialBus (0x0018, ControllerInitiated, 0x00061A80, + AddressingMode7Bit, "\\_SB.I2C6", 0x00, + ResourceConsumer, ,) + GpioInt (Edge, ActiveHigh, Exclusive, PullDown, 0x0000, + "\\_SB.GPO2", 0x00, ResourceConsumer, , ) + { // Pin list + 0 + } + }) Method (_CRS, 0, Serialized) { - Name (RBUF, ResourceTemplate () - { - I2cSerialBus (0x0018, ControllerInitiated, 0x00061A80, - AddressingMode7Bit, "\\_SB.I2C6", 0x00, - ResourceConsumer, ,) - GpioInt (Edge, ActiveHigh, Exclusive, PullDown, 0x0000, - "\\_SB.GPO2", 0x00, ResourceConsumer, , ) - { // Pin list - 0 - } - }) Return (RBUF) } } @@ -75,7 +74,7 @@ This option allows loading of user defined SSDTs from initrd and it is useful when the system does not support EFI or when there is not enough EFI storage. It works in a similar way with initrd based ACPI tables override/upgrade: SSDT -aml code must be placed in the first, uncompressed, initrd under the +AML code must be placed in the first, uncompressed, initrd under the "kernel/firmware/acpi" path. Multiple files can be used and this will translate in loading multiple tables. Only SSDT and OEM tables are allowed. See initrd_table_override.txt for more details. @@ -103,12 +102,14 @@ This is the preferred method, when EFI is supported on the platform, because it allows a persistent, OS independent way of storing the user defined SSDTs. There is also work underway to implement EFI support for loading user defined SSDTs and using this method will make it easier to convert to the EFI loading -mechanism when that will arrive. +mechanism when that will arrive. To enable it, the +CONFIG_EFI_CUSTOM_SSDT_OVERLAYS shoyld be chosen to y. -In order to load SSDTs from an EFI variable the efivar_ssdt kernel command line -parameter can be used. The argument for the option is the variable name to -use. If there are multiple variables with the same name but with different -vendor GUIDs, all of them will be loaded. +In order to load SSDTs from an EFI variable the ``"efivar_ssdt=..."`` kernel +command line parameter can be used (the name has a limitation of 16 characters). +The argument for the option is the variable name to use. If there are multiple +variables with the same name but with different vendor GUIDs, all of them will +be loaded. In order to store the AML code in an EFI variable the efivarfs filesystem can be used. It is enabled and mounted by default in /sys/firmware/efi/efivars in all @@ -127,7 +128,7 @@ variable with the content from a given file:: #!/bin/sh -e - while ! [ -z "$1" ]; do + while [ -n "$1" ]; do case "$1" in "-f") filename="$2"; shift;; "-g") guid="$2"; shift;; @@ -167,14 +168,14 @@ variable with the content from a given file:: Loading ACPI SSDTs from configfs ================================ -This option allows loading of user defined SSDTs from userspace via the configfs +This option allows loading of user defined SSDTs from user space via the configfs interface. The CONFIG_ACPI_CONFIGFS option must be select and configfs must be mounted. In the following examples, we assume that configfs has been mounted in -/config. +/sys/kernel/config. -New tables can be loading by creating new directories in /config/acpi/table/ and -writing the SSDT aml code in the aml attribute:: +New tables can be loading by creating new directories in /sys/kernel/config/acpi/table +and writing the SSDT AML code in the aml attribute:: - cd /config/acpi/table + cd /sys/kernel/config/acpi/table mkdir my_ssdt cat ~/ssdt.aml > my_ssdt/aml diff --git a/Documentation/admin-guide/bootconfig.rst b/Documentation/admin-guide/bootconfig.rst index 6a79f2e59396..a1860fc0ca88 100644 --- a/Documentation/admin-guide/bootconfig.rst +++ b/Documentation/admin-guide/bootconfig.rst @@ -178,7 +178,7 @@ update the boot loader and the kernel image itself as long as the boot loader passes the correct initrd file size. If by any chance, the boot loader passes a longer size, the kernel fails to find the bootconfig data. -To do this operation, Linux kernel provides "bootconfig" command under +To do this operation, Linux kernel provides ``bootconfig`` command under tools/bootconfig, which allows admin to apply or delete the config file to/from initrd image. You can build it by the following command:: @@ -196,6 +196,43 @@ To remove the config from the image, you can use -d option as below:: Then add "bootconfig" on the normal kernel command line to tell the kernel to look for the bootconfig at the end of the initrd file. + +Kernel parameters via Boot Config +================================= + +In addition to the kernel command line, the boot config can be used for +passing the kernel parameters. All the key-value pairs under ``kernel`` +key will be passed to kernel cmdline directly. Moreover, the key-value +pairs under ``init`` will be passed to init process via the cmdline. +The parameters are concatinated with user-given kernel cmdline string +as the following order, so that the command line parameter can override +bootconfig parameters (this depends on how the subsystem handles parameters +but in general, earlier parameter will be overwritten by later one.):: + + [bootconfig params][cmdline params] -- [bootconfig init params][cmdline init params] + +Here is an example of the bootconfig file for kernel/init parameters.:: + + kernel { + root = 01234567-89ab-cdef-0123-456789abcd + } + init { + splash + } + +This will be copied into the kernel cmdline string as the following:: + + root="01234567-89ab-cdef-0123-456789abcd" -- splash + +If user gives some other command line like,:: + + ro bootconfig -- quiet + +The final kernel cmdline will be the following:: + + root="01234567-89ab-cdef-0123-456789abcd" ro bootconfig -- splash quiet + + Config File Limitation ====================== diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 828d11441ebf..91ba391f9b32 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1758,6 +1758,11 @@ support for the idxd driver. By default it is set to true (1). + idxd.tc_override= [HW] + Format: <bool> + Allow override of default traffic class configuration + for the device. By default it is set to false (0). + ieee754= [MIPS] Select IEEE Std 754 conformance mode Format: { strict | legacy | 2008 | relaxed } Default: strict |