Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 211 insertions, 0 deletions

diff --git a/Documentation/admin-guide/kernel-parameters.rst b/Documentation/admin-guide/kernel-parameters.rst
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+.. _kernelparameters:
+
+The kernel's command-line parameters
+====================================
+
+The following is a consolidated list of the kernel parameters as
+implemented by the __setup(), core_param() and module_param() macros
+and sorted into English Dictionary order (defined as ignoring all
+punctuation and sorting digits before letters in a case insensitive
+manner), and with descriptions where known.
+
+The kernel parses parameters from the kernel command line up to "--";
+if it doesn't recognize a parameter and it doesn't contain a '.', the
+parameter gets passed to init: parameters with '=' go into init's
+environment, others are passed as command line arguments to init.
+Everything after "--" is passed as an argument to init.
+
+Module parameters can be specified in two ways: via the kernel command
+line with a module name prefix, or via modprobe, e.g.::
+
+	(kernel command line) usbcore.blinkenlights=1
+	(modprobe command line) modprobe usbcore blinkenlights=1
+
+Parameters for modules which are built into the kernel need to be
+specified on the kernel command line.  modprobe looks through the
+kernel command line (/proc/cmdline) and collects module parameters
+when it loads a module, so the kernel command line can be used for
+loadable modules too.
+
+Hyphens (dashes) and underscores are equivalent in parameter names, so::
+
+	log_buf_len=1M print-fatal-signals=1
+
+can also be entered as::
+
+	log-buf-len=1M print_fatal_signals=1
+
+Double-quotes can be used to protect spaces in values, e.g.::
+
+	param="spaces in here"
+
+cpu lists:
+----------
+
+Some kernel parameters take a list of CPUs as a value, e.g.  isolcpus,
+nohz_full, irqaffinity, rcu_nocbs.  The format of this list is:
+
+	<cpu number>,...,<cpu number>
+
+or
+
+	<cpu number>-<cpu number>
+	(must be a positive range in ascending order)
+
+or a mixture
+
+<cpu number>,...,<cpu number>-<cpu number>
+
+Note that for the special case of a range one can split the range into equal
+sized groups and for each group use some amount from the beginning of that
+group:
+
+	<cpu number>-cpu number>:<used size>/<group size>
+
+For example one can add to the command line following parameter:
+
+	isolcpus=1,2,10-20,100-2000:2/25
+
+where the final item represents CPUs 100,101,125,126,150,151,...
+
+
+
+This document may not be entirely up to date and comprehensive. The command
+"modinfo -p ${modulename}" shows a current list of all parameters of a loadable
+module. Loadable modules, after being loaded into the running kernel, also
+reveal their parameters in /sys/module/${modulename}/parameters/. Some of these
+parameters may be changed at runtime by the command
+``echo -n ${value} > /sys/module/${modulename}/parameters/${parm}``.
+
+The parameters listed below are only valid if certain kernel build options were
+enabled and if respective hardware is present. The text in square brackets at
+the beginning of each description states the restrictions within which a
+parameter is applicable::
+
+	ACPI	ACPI support is enabled.
+	AGP	AGP (Accelerated Graphics Port) is enabled.
+	ALSA	ALSA sound support is enabled.
+	APIC	APIC support is enabled.
+	APM	Advanced Power Management support is enabled.
+	ARM	ARM architecture is enabled.
+	AX25	Appropriate AX.25 support is enabled.
+	CLK	Common clock infrastructure is enabled.
+	CMA	Contiguous Memory Area support is enabled.
+	DRM	Direct Rendering Management support is enabled.
+	DYNAMIC_DEBUG Build in debug messages and enable them at runtime
+	EDD	BIOS Enhanced Disk Drive Services (EDD) is enabled
+	EFI	EFI Partitioning (GPT) is enabled
+	EIDE	EIDE/ATAPI support is enabled.
+	EVM	Extended Verification Module
+	FB	The frame buffer device is enabled.
+	FTRACE	Function tracing enabled.
+	GCOV	GCOV profiling is enabled.
+	HW	Appropriate hardware is enabled.
+	IA-64	IA-64 architecture is enabled.
+	IMA     Integrity measurement architecture is enabled.
+	IOSCHED	More than one I/O scheduler is enabled.
+	IP_PNP	IP DHCP, BOOTP, or RARP is enabled.
+	IPV6	IPv6 support is enabled.
+	ISAPNP	ISA PnP code is enabled.
+	ISDN	Appropriate ISDN support is enabled.
+	ISOL	CPU Isolation is enabled.
+	JOY	Appropriate joystick support is enabled.
+	KGDB	Kernel debugger support is enabled.
+	KVM	Kernel Virtual Machine support is enabled.
+	LIBATA  Libata driver is enabled
+	LP	Printer support is enabled.
+	LOOP	Loopback device support is enabled.
+	M68k	M68k architecture is enabled.
+			These options have more detailed description inside of
+			Documentation/m68k/kernel-options.txt.
+	MDA	MDA console support is enabled.
+	MIPS	MIPS architecture is enabled.
+	MOUSE	Appropriate mouse support is enabled.
+	MSI	Message Signaled Interrupts (PCI).
+	MTD	MTD (Memory Technology Device) support is enabled.
+	NET	Appropriate network support is enabled.
+	NUMA	NUMA support is enabled.
+	NFS	Appropriate NFS support is enabled.
+	OSS	OSS sound support is enabled.
+	PV_OPS	A paravirtualized kernel is enabled.
+	PARIDE	The ParIDE (parallel port IDE) subsystem is enabled.
+	PARISC	The PA-RISC architecture is enabled.
+	PCI	PCI bus support is enabled.
+	PCIE	PCI Express support is enabled.
+	PCMCIA	The PCMCIA subsystem is enabled.
+	PNP	Plug & Play support is enabled.
+	PPC	PowerPC architecture is enabled.
+	PPT	Parallel port support is enabled.
+	PS2	Appropriate PS/2 support is enabled.
+	RAM	RAM disk support is enabled.
+	RDT	Intel Resource Director Technology.
+	S390	S390 architecture is enabled.
+	SCSI	Appropriate SCSI support is enabled.
+			A lot of drivers have their options described inside
+			the Documentation/scsi/ sub-directory.
+	SECURITY Different security models are enabled.
+	SELINUX SELinux support is enabled.
+	APPARMOR AppArmor support is enabled.
+	SERIAL	Serial support is enabled.
+	SH	SuperH architecture is enabled.
+	SMP	The kernel is an SMP kernel.
+	SPARC	Sparc architecture is enabled.
+	SWSUSP	Software suspend (hibernation) is enabled.
+	SUSPEND	System suspend states are enabled.
+	TPM	TPM drivers are enabled.
+	TS	Appropriate touchscreen support is enabled.
+	UMS	USB Mass Storage support is enabled.
+	USB	USB support is enabled.
+	USBHID	USB Human Interface Device support is enabled.
+	V4L	Video For Linux support is enabled.
+	VMMIO   Driver for memory mapped virtio devices is enabled.
+	VGA	The VGA console has been enabled.
+	VT	Virtual terminal support is enabled.
+	WDT	Watchdog support is enabled.
+	XT	IBM PC/XT MFM hard disk support is enabled.
+	X86-32	X86-32, aka i386 architecture is enabled.
+	X86-64	X86-64 architecture is enabled.
+			More X86-64 boot options can be found in
+			Documentation/x86/x86_64/boot-options.txt .
+	X86	Either 32-bit or 64-bit x86 (same as X86-32+X86-64)
+	X86_UV	SGI UV support is enabled.
+	XEN	Xen support is enabled
+
+In addition, the following text indicates that the option::
+
+	BUGS=	Relates to possible processor bugs on the said processor.
+	KNL	Is a kernel start-up parameter.
+	BOOT	Is a boot loader parameter.
+
+Parameters denoted with BOOT are actually interpreted by the boot
+loader, and have no meaning to the kernel directly.
+Do not modify the syntax of boot loader parameters without extreme
+need or coordination with <Documentation/x86/boot.txt>.
+
+There are also arch-specific kernel-parameters not documented here.
+See for example <Documentation/x86/x86_64/boot-options.txt>.
+
+Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
+a trailing = on the name of any parameter states that that parameter will
+be entered as an environment variable, whereas its absence indicates that
+it will appear as a kernel argument readable via /proc/cmdline by programs
+running once the system is up.
+
+The number of kernel parameters is not limited, but the length of the
+complete command line (parameters including spaces etc.) is limited to
+a fixed number of characters. This limit depends on the architecture
+and is between 256 and 4096 characters. It is defined in the file
+./include/asm/setup.h as COMMAND_LINE_SIZE.
+
+Finally, the [KMG] suffix is commonly described after a number of kernel
+parameter values. These 'K', 'M', and 'G' letters represent the _binary_
+multipliers 'Kilo', 'Mega', and 'Giga', equaling 2^10, 2^20, and 2^30
+bytes respectively. Such letter suffixes can also be entirely omitted:
+
+.. include:: kernel-parameters.txt
+   :literal:
+
+Todo
+----
+
+	Add more DRM drivers.