All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH] update earlyprintk documentation (and kill x86 copy)
@ 2013-04-10 21:03 Dave Hansen
  2013-04-11 12:19 ` [tip:x86/debug] x86, early-printk: Update " tip-bot for Dave Hansen
  0 siblings, 1 reply; 2+ messages in thread
From: Dave Hansen @ 2013-04-10 21:03 UTC (permalink / raw)
  To: linux-kernel
  Cc: Rob Landley, linux-doc, x86, Catalin Marinas, Thomas Gleixner,
	Dave Hansen


Documentation/kernel-parameters.txt and
Documentation/x86/x86_64/boot-options.txt contain virtually identical
text describing earlyprintk.

This consolidates the two copies and updates the documentation a
bit.  No one ever documented the:

	earlyprintk=serial,0x1008,115200

syntax, nor mentioned that ARM is now a supported earlyprintk arch.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
---

 linux.git-davehans/Documentation/kernel-parameters.txt       |   16 +++++++++--
 linux.git-davehans/Documentation/x86/x86_64/boot-options.txt |   14 ---------
 2 files changed, 14 insertions(+), 16 deletions(-)

diff -puN Documentation/kernel-parameters.txt~early-printk-morettys Documentation/kernel-parameters.txt
--- linux.git/Documentation/kernel-parameters.txt~early-printk-morettys	2013-04-10 13:30:37.422949520 -0700
+++ linux.git-davehans/Documentation/kernel-parameters.txt	2013-04-10 13:30:37.428949526 -0700
@@ -757,19 +757,31 @@ bytes respectively. Such letter suffixes
 			(mmio) or 32-bit (mmio32).
 			The options are the same as for ttyS, above.
 
-	earlyprintk=	[X86,SH,BLACKFIN]
+	earlyprintk=	[X86,SH,BLACKFIN,ARM]
 			earlyprintk=vga
 			earlyprintk=xen
 			earlyprintk=serial[,ttySn[,baudrate]]
+			earlyprintk=serial[,0x...[,baudrate]]
 			earlyprintk=ttySn[,baudrate]
 			earlyprintk=dbgp[debugController#]
 
+			earlyprintk is useful when the kernel crashes before
+			the normal console is initialized. It is not enabled by
+			default because it has some cosmetic problems.
+
 			Append ",keep" to not disable it when the real console
 			takes over.
 
 			Only vga or serial or usb debug port at a time.
 
-			Currently only ttyS0 and ttyS1 are supported.
+			Currently only ttyS0 and ttyS1 may be specified by
+			name.  Other I/O ports may be explicitly specified
+			on some architectures (x86 and arm at least) by
+			replacing ttySn with an I/O port address, like this:
+				earlyprintk=serial,0x1008,115200
+			You can find the port for a given device in
+			/proc/tty/driver/serial:
+				2: uart:ST16650V2 port:00001008 irq:18 ...
 
 			Interaction with the standard serial driver is not
 			very good.
diff -puN Documentation/x86/x86_64/boot-options.txt~early-printk-morettys Documentation/x86/x86_64/boot-options.txt
--- linux.git/Documentation/x86/x86_64/boot-options.txt~early-printk-morettys	2013-04-10 13:30:37.424949522 -0700
+++ linux.git-davehans/Documentation/x86/x86_64/boot-options.txt	2013-04-10 13:30:37.428949526 -0700
@@ -91,20 +91,6 @@ APICs
 		 apicmaintimer. Useful when your PIT timer is totally
 		 broken.
 
-Early Console
-
-   syntax: earlyprintk=vga
-           earlyprintk=serial[,ttySn[,baudrate]]
-
-   The early console is useful when the kernel crashes before the
-   normal console is initialized. It is not enabled by
-   default because it has some cosmetic problems.
-   Append ,keep to not disable it when the real console takes over.
-   Only vga or serial at a time, not both.
-   Currently only ttyS0 and ttyS1 are supported.
-   Interaction with the standard serial driver is not very good.
-   The VGA output is eventually overwritten by the real console.
-
 Timing
 
   notsc
_

^ permalink raw reply	[flat|nested] 2+ messages in thread

* [tip:x86/debug] x86, early-printk: Update earlyprintk documentation (and kill x86 copy)
  2013-04-10 21:03 [PATCH] update earlyprintk documentation (and kill x86 copy) Dave Hansen
@ 2013-04-11 12:19 ` tip-bot for Dave Hansen
  0 siblings, 0 replies; 2+ messages in thread
From: tip-bot for Dave Hansen @ 2013-04-11 12:19 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: linux-kernel, hpa, mingo, catalin.marinas, dave, tglx,
	dave.hansen, rob

Commit-ID:  147ea09119e45caf2e8bf57c9e54cc930ccfeda9
Gitweb:     http://git.kernel.org/tip/147ea09119e45caf2e8bf57c9e54cc930ccfeda9
Author:     Dave Hansen <dave@sr71.net>
AuthorDate: Wed, 10 Apr 2013 14:03:38 -0700
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 11 Apr 2013 10:30:40 +0200

x86, early-printk: Update earlyprintk documentation (and kill x86 copy)

Documentation/kernel-parameters.txt and
Documentation/x86/x86_64/boot-options.txt contain virtually
identical text describing earlyprintk.

This consolidates the two copies and updates the documentation a
bit.  No one ever documented the:

	earlyprintk=serial,0x1008,115200

syntax, nor mentioned that ARM is now a supported earlyprintk
arch.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Rob Landley <rob@landley.net>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave@sr71.net>
Link: http://lkml.kernel.org/r/20130410210338.E2930E98@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 Documentation/kernel-parameters.txt       | 16 ++++++++++++++--
 Documentation/x86/x86_64/boot-options.txt | 14 --------------
 2 files changed, 14 insertions(+), 16 deletions(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 4609e81..b5cfd04 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -757,19 +757,31 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 			(mmio) or 32-bit (mmio32).
 			The options are the same as for ttyS, above.
 
-	earlyprintk=	[X86,SH,BLACKFIN]
+	earlyprintk=	[X86,SH,BLACKFIN,ARM]
 			earlyprintk=vga
 			earlyprintk=xen
 			earlyprintk=serial[,ttySn[,baudrate]]
+			earlyprintk=serial[,0x...[,baudrate]]
 			earlyprintk=ttySn[,baudrate]
 			earlyprintk=dbgp[debugController#]
 
+			earlyprintk is useful when the kernel crashes before
+			the normal console is initialized. It is not enabled by
+			default because it has some cosmetic problems.
+
 			Append ",keep" to not disable it when the real console
 			takes over.
 
 			Only vga or serial or usb debug port at a time.
 
-			Currently only ttyS0 and ttyS1 are supported.
+			Currently only ttyS0 and ttyS1 may be specified by
+			name.  Other I/O ports may be explicitly specified
+			on some architectures (x86 and arm at least) by
+			replacing ttySn with an I/O port address, like this:
+				earlyprintk=serial,0x1008,115200
+			You can find the port for a given device in
+			/proc/tty/driver/serial:
+				2: uart:ST16650V2 port:00001008 irq:18 ...
 
 			Interaction with the standard serial driver is not
 			very good.
diff --git a/Documentation/x86/x86_64/boot-options.txt b/Documentation/x86/x86_64/boot-options.txt
index e015a83..e9e8ddb 100644
--- a/Documentation/x86/x86_64/boot-options.txt
+++ b/Documentation/x86/x86_64/boot-options.txt
@@ -91,20 +91,6 @@ APICs
 		 apicmaintimer. Useful when your PIT timer is totally
 		 broken.
 
-Early Console
-
-   syntax: earlyprintk=vga
-           earlyprintk=serial[,ttySn[,baudrate]]
-
-   The early console is useful when the kernel crashes before the
-   normal console is initialized. It is not enabled by
-   default because it has some cosmetic problems.
-   Append ,keep to not disable it when the real console takes over.
-   Only vga or serial at a time, not both.
-   Currently only ttyS0 and ttyS1 are supported.
-   Interaction with the standard serial driver is not very good.
-   The VGA output is eventually overwritten by the real console.
-
 Timing
 
   notsc

^ permalink raw reply related	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2013-04-11 12:19 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-04-10 21:03 [PATCH] update earlyprintk documentation (and kill x86 copy) Dave Hansen
2013-04-11 12:19 ` [tip:x86/debug] x86, early-printk: Update " tip-bot for Dave Hansen

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.