[PATCH] kexec/kdump: Minor Documentation updates for arm64 and Image

Discussion:

Bharat Bhushan

2017-05-18 05:33:20 UTC

This patch have minor updates in Documentation for arm64i as
relocatable kernel.
Also this patch updates documentation for using uncompressed
image "Image" which is used for ARM64.

Signed-off-by: Bharat Bhushan <***@nxp.com>
---
Documentation/kdump/kdump.txt | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/Documentation/kdump/kdump.txt b/Documentation/kdump/kdump.txt
index 615434d..522ce13 100644
--- a/Documentation/kdump/kdump.txt
+++ b/Documentation/kdump/kdump.txt
@@ -112,8 +112,8 @@ There are two possible methods of using Kdump.
2) Or use the system kernel binary itself as dump-capture kernel and there is
no need to build a separate dump-capture kernel. This is possible
only with the architectures which support a relocatable kernel. As
- of today, i386, x86_64, ppc64, ia64 and arm architectures support relocatable
- kernel.
+ of today, i386, x86_64, ppc64, ia64, arm and arm64 architectures support
+ relocatable kernel.

Building a relocatable kernel is advantageous from the point of view that
one does not have to build a second kernel for capturing the dump. But
@@ -361,6 +361,12 @@ to load dump-capture kernel.
--dtb=<dtb-for-dump-capture-kernel> \
--append="root=<root-dev> <arch-specific-options>"

+If you are using a uncompressed Image, then use following command
+to load dump-capture kernel.
+
+ kexec -p <dump-capture-kernel-Image> \
+ --initrd=<initrd-for-dump-capture-kernel> \
+ --append="root=<root-dev> <arch-specific-options>"

Please note, that --args-linux does not need to be specified for ia64.
It is planned to make this a no-op on that architecture, but for now

--
1.9.3

Baoquan He

2017-05-18 05:45:22 UTC

Permalink

Post by Bharat Bhushan
This patch have minor updates in Documentation for arm64i as
relocatable kernel.
Also this patch updates documentation for using uncompressed
image "Image" which is used for ARM64.
---
Documentation/kdump/kdump.txt | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/Documentation/kdump/kdump.txt b/Documentation/kdump/kdump.txt
index 615434d..522ce13 100644
--- a/Documentation/kdump/kdump.txt
+++ b/Documentation/kdump/kdump.txt
@@ -112,8 +112,8 @@ There are two possible methods of using Kdump.
2) Or use the system kernel binary itself as dump-capture kernel and there is
no need to build a separate dump-capture kernel. This is possible
only with the architectures which support a relocatable kernel. As
- of today, i386, x86_64, ppc64, ia64 and arm architectures support relocatable
- kernel.
+ of today, i386, x86_64, ppc64, ia64, arm and arm64 architectures support
+ relocatable kernel.
Building a relocatable kernel is advantageous from the point of view that
one does not have to build a second kernel for capturing the dump. But
@@ -361,6 +361,12 @@ to load dump-capture kernel.
--dtb=<dtb-for-dump-capture-kernel> \
--append="root=<root-dev> <arch-specific-options>"
+If you are using a uncompressed Image, then use following command

~ an

Post by Bharat Bhushan
+to load dump-capture kernel.
+
+ kexec -p <dump-capture-kernel-Image> \
+ --initrd=<initrd-for-dump-capture-kernel> \
+ --append="root=<root-dev> <arch-specific-options>"
Please note, that --args-linux does not need to be specified for ia64.
It is planned to make this a no-op on that architecture, but for now
--
1.9.3

Dave Young

2017-05-18 05:59:14 UTC

Permalink

Add Takahiro and Pratyush, they should be able to review the arm64 part.

s/a/an

Post by Bharat Bhushan
+to load dump-capture kernel.
+
+ kexec -p <dump-capture-kernel-Image> \
+ --initrd=<initrd-for-dump-capture-kernel> \
+ --append="root=<root-dev> <arch-specific-options>"

For uncompressed Image, dtb is not necessary?

Post by Bharat Bhushan
Please note, that --args-linux does not need to be specified for ia64.
It is planned to make this a no-op on that architecture, but for now
--
1.9.3

Thanks
Dave

Bharat Bhushan

2017-05-18 06:14:07 UTC

Permalink

-----Original Message-----
Sent: Thursday, May 18, 2017 11:29 AM
Subject: Re: [PATCH] kexec/kdump: Minor Documentation updates for
arm64 and Image
Add Takahiro and Pratyush, they should be able to review the arm64 part.

Post by Bharat Bhushan
no need to build a separate dump-capture kernel. This is possible
only with the architectures which support a relocatable kernel. As
- of today, i386, x86_64, ppc64, ia64 and arm architectures support

relocatable

Post by Bharat Bhushan
- kernel.
+ of today, i386, x86_64, ppc64, ia64, arm and arm64 architectures support
+ relocatable kernel.
Building a relocatable kernel is advantageous from the point of view
that one does not have to build a second kernel for capturing the
--dtb=<dtb-for-dump-capture-kernel> \
--append="root=<root-dev> <arch-specific-options>"
+If you are using a uncompressed Image, then use following command

s/a/an

Post by Bharat Bhushan
+to load dump-capture kernel.
+
+ kexec -p <dump-capture-kernel-Image> \
+ --initrd=<initrd-for-dump-capture-kernel> \
+ --append="root=<root-dev> <arch-specific-options>"

For uncompressed Image, dtb is not necessary?

Yes dtb is not necessary, it works for me without giving dtb.

Thanks
-Bharat

Post by Bharat Bhushan
Please note, that --args-linux does not need to be specified for ia64.
It is planned to make this a no-op on that architecture, but for now
--
1.9.3

Thanks
Dave

AKASHI Takahiro

2017-05-19 03:45:15 UTC

Permalink

Post by Dave Young
Add Takahiro and Pratyush, they should be able to review the arm64 part.

s/a/an

Post by Bharat Bhushan
+to load dump-capture kernel.
+
+ kexec -p <dump-capture-kernel-Image> \
+ --initrd=<initrd-for-dump-capture-kernel> \
+ --append="root=<root-dev> <arch-specific-options>"

For uncompressed Image, dtb is not necessary?

Just for clarification, dtb is optional for both vmlinux and Image
on arm64. (This means you can specify it if you want.)
But this is also true for initrd and append(command line) to some extent.

More precisely, whether these parameters are optional or not will
depend on architectures, not formats, I believe.

Thanks,
-Takahiro AKASHI

Post by Dave Young

Post by Bharat Bhushan
Please note, that --args-linux does not need to be specified for ia64.
It is planned to make this a no-op on that architecture, but for now
--
1.9.3

Thanks
Dave

Pratyush Anand

2017-05-22 06:39:26 UTC

Permalink

Post by AKASHI Takahiro

Post by Dave Young

Post by Bharat Bhushan
+to load dump-capture kernel.
+
+ kexec -p <dump-capture-kernel-Image> \
+ --initrd=<initrd-for-dump-capture-kernel> \
+ --append="root=<root-dev> <arch-specific-options>"

For uncompressed Image, dtb is not necessary?

Just for clarification, dtb is optional for both vmlinux and Image
on arm64. (This means you can specify it if you want.)
But this is also true for initrd and append(command line) to some extent.

Yes, I agree.

Post by AKASHI Takahiro
More precisely, whether these parameters are optional or not will
depend on architectures, not formats, I believe.

May be not architecture, rather a distro environment.

For example, we should be able to work without --initrd for any arch if kernel
has been compiled by configuring CONFG_INITRAMFS_SOURCE.

~Pratyush

Bharat Bhushan

2017-05-22 06:49:13 UTC

Permalink

-----Original Message-----
Sent: Monday, May 22, 2017 12:09 PM
Subject: Re: [PATCH] kexec/kdump: Minor Documentation updates for
arm64 and Image

Post by Dave Young

Post by Bharat Bhushan
+to load dump-capture kernel.
+
+ kexec -p <dump-capture-kernel-Image> \
+ --initrd=<initrd-for-dump-capture-kernel> \
+ --append="root=<root-dev> <arch-specific-options>"

For uncompressed Image, dtb is not necessary?

Just for clarification, dtb is optional for both vmlinux and Image on
arm64. (This means you can specify it if you want.) But this is also
true for initrd and append(command line) to some extent.

Yes, I agree.

Should I mention "-dtb" also for "Image"?

Also do we need to mention that it is optional somewhere in this document? I do not see "optional" is mentioned for other parameters and architecture.

Does this looks ok:

" -dtb=<optional-dtb-for-dump-capture-kernel> \"

Thanks
-Bharat

More precisely, whether these parameters are optional or not will
depend on architectures, not formats, I believe.

May be not architecture, rather a distro environment.
For example, we should be able to work without --initrd for any arch if kernel
has been compiled by configuring CONFG_INITRAMFS_SOURCE.
~Pratyush

Pratyush Anand

2017-05-22 07:05:04 UTC

Permalink

Post by Bharat Bhushan

Post by Pratyush Anand

Post by Dave Young

Post by Bharat Bhushan
+to load dump-capture kernel.
+
+ kexec -p <dump-capture-kernel-Image> \
+ --initrd=<initrd-for-dump-capture-kernel> \
+ --append="root=<root-dev> <arch-specific-options>"

For uncompressed Image, dtb is not necessary?

Just for clarification, dtb is optional for both vmlinux and Image on
arm64. (This means you can specify it if you want.) But this is also
true for initrd and append(command line) to some extent.

Yes, I agree.

Should I mention "-dtb" also for "Image"?

No,I think it is fine.

This documentation is representing a typical use case and so above changes is
OK for me. I think,your v2 is fine.

~Pratyush

Post by Bharat Bhushan
Also do we need to mention that it is optional somewhere in this document? I do not see "optional" is mentioned for other parameters and architecture.
" -dtb=<optional-dtb-for-dump-capture-kernel> \"
Thanks
-Bharat

Post by Pratyush Anand

More precisely, whether these parameters are optional or not will
depend on architectures, not formats, I believe.

May be not architecture, rather a distro environment.
For example, we should be able to work without --initrd for any arch if kernel
has been compiled by configuring CONFG_INITRAMFS_SOURCE.
~Pratyush