s390: provide sclp based boot console
Use the early sclp code to provide a boot console. This boot console
is available if the kernel parameter "earlyprintk" has been specified,
just like it works for other architectures that also provide an early
boot console.
This makes debugging of early problems much easier, since now we
finally have working console output even before memory detection is
running.
The boot console will be automatically disabled as soon as another
console will be registered.
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index be7c0d9..ef77c55 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -979,9 +979,10 @@
address. The serial port must already be setup
and configured. Options are not yet supported.
- earlyprintk= [X86,SH,BLACKFIN,ARM,M68k]
+ earlyprintk= [X86,SH,BLACKFIN,ARM,M68k,S390]
earlyprintk=vga
earlyprintk=efi
+ earlyprintk=sclp
earlyprintk=xen
earlyprintk=serial[,ttySn[,baudrate]]
earlyprintk=serial[,0x...[,baudrate]]
@@ -1016,6 +1017,8 @@
The xen output can only be used by Xen PV guests.
+ The sclp output can only be used on s390.
+
edac_report= [HW,EDAC] Control how to report EDAC event
Format: {"on" | "off" | "force"}
on: enable EDAC to report H/W event. May be overridden