UART at the specified I/O port or MMIO address,
switching to the matching ttyS device later. The
options are the same as for ttyS, above.
+ hvc<n> Use the hypervisor console device <n>. This is for
+ both Xen and PowerPC hypervisors.
If the device connected to the port is not a TTY but a braille
device, prepend "brl," before the device type, for instance
is selected automatically. Check
Documentation/kdump/kdump.txt for further details.
+ crashkernel_low=size[KMG]
+ [KNL, x86] parts under 4G.
+
crashkernel=range1:size1[,range2:size2,...][@offset]
[KNL] Same as above, but depends on the memory
in the running system. The syntax of range is
earlyprintk= [X86,SH,BLACKFIN]
earlyprintk=vga
+ earlyprintk=xen
earlyprintk=serial[,ttySn[,baudrate]]
earlyprintk=ttySn[,baudrate]
earlyprintk=dbgp[debugController#]
The VGA output is eventually overwritten by the real
console.
+ The xen output can only be used by Xen PV guests.
+
ekgdboc= [X86,KGDB] Allow early kernel console debugging
ekgdboc=kbd
If specified, z/VM IUCV HVC accepts connections
from listed z/VM user IDs only.
+ hwthread_map= [METAG] Comma-separated list of Linux cpu id to
+ hardware thread id mappings.
+ Format: <cpu>:<hwthread>
+
keep_bootcon [KNL]
Do not unregister boot console at start. This is only
useful for debugging when something happens in the window
This sorting is done to get a device
order compatible with older (<= 2.4) kernels.
nobfsort Don't sort PCI devices into breadth-first order.
+ pcie_bus_tune_off Disable PCIe MPS (Max Payload Size)
+ tuning and use the BIOS-configured MPS defaults.
+ pcie_bus_safe Set every device's MPS to the largest value
+ supported by all devices below the root complex.
+ pcie_bus_perf Set device MPS to the largest allowable MPS
+ based on its parent bus. Also set MRRS (Max
+ Read Request Size) to the largest supported
+ value (no larger than the MPS that the device
+ or bus can support) for best performance.
+ pcie_bus_peer2peer Set every device's MPS to 128B, which
+ every device is guaranteed to support. This
+ configuration allows peer-to-peer DMA between
+ any pair of devices, possibly at the cost of
+ reduced performance. This also guarantees
+ that hot-added devices will work.
cbiosize=nn[KMG] The fixed amount of bus space which is
reserved for the CardBus bridge's IO window.
The default value is 256 bytes.
the default.
off: Turn ECRC off
on: Turn ECRC on.
+ hpiosize=nn[KMG] The fixed amount of bus space which is
+ reserved for hotplug bridge's IO window.
+ Default size is 256 bytes.
+ hpmemsize=nn[KMG] The fixed amount of bus space which is
+ reserved for hotplug bridge's memory window.
+ Default size is 2 megabytes.
realloc= Enable/disable reallocating PCI bridge resources
if allocations done by BIOS are too small to
accommodate resources required by all child