2018-05-06 18:50:59

by Randy Dunlap

[permalink] [raw]
Subject: [PATCH] Documentation: block: cmdline-partition.txt fixes and additions

From: Randy Dunlap <[email protected]>

Make the description of the kernel command line option "blkdevparts"
a bit more flowing and readable.

Fix a few typos.
Add the optional <size> and <offset> suffixes.
Note that size can be "-" to indicate all of the remaining space.

Signed-off-by: Randy Dunlap <[email protected]>
Cc: Cai Zhiyong <[email protected]>
---
Should the "ro" and "lk" flags options be described?

Documentation/block/cmdline-partition.txt | 21 +++++++++++++-------
1 file changed, 14 insertions(+), 7 deletions(-)

--- linux-next-20180504.orig/Documentation/block/cmdline-partition.txt
+++ linux-next-20180504/Documentation/block/cmdline-partition.txt
@@ -1,7 +1,9 @@
Embedded device command line partition parsing
=====================================================================

-Support for reading the block device partition table from the command line.
+The "blkdevparts" command line option adds support for reading the
+block device partition table from the kernel command line.
+
It is typically used for fixed block (eMMC) embedded devices.
It has no MBR, so saves storage space. Bootloader can be easily accessed
by absolute address of data on the block device.
@@ -14,22 +16,27 @@ blkdevparts=<blkdev-def>[;<blkdev-def>]
<partdef> := <size>[@<offset>](part-name)

<blkdev-id>
- block device disk name, embedded device used fixed block device,
- it's disk name also fixed. such as: mmcblk0, mmcblk1, mmcblk0boot0.
+ block device disk name. Embedded device uses fixed block device.
+ Its disk name is also fixed, such as: mmcblk0, mmcblk1, mmcblk0boot0.

<size>
partition size, in bytes, such as: 512, 1m, 1G.
+ size may contain an optional suffix of (upper or lower case):
+ K, M, G, T, P, E.
+ "-" is used to denote all remaining space.

<offset>
partition start address, in bytes.
+ offset may contain an optional suffix of (upper or lower case):
+ K, M, G, T, P, E.

(part-name)
- partition name, kernel send uevent with "PARTNAME". application can create
- a link to block device partition with the name "PARTNAME".
- user space application can access partition by partition name.
+ partition name. Kernel sends uevent with "PARTNAME". Application can
+ create a link to block device partition with the name "PARTNAME".
+ User space application can access partition by partition name.

Example:
- eMMC disk name is "mmcblk0" and "mmcblk0boot0"
+ eMMC disk names are "mmcblk0" and "mmcblk0boot0".

bootargs:
'blkdevparts=mmcblk0:1G(data0),1G(data1),-;mmcblk0boot0:1m(boot),-(kernel)'



2018-05-07 02:46:08

by Caizhiyong

[permalink] [raw]
Subject: RE: [PATCH] Documentation: block: cmdline-partition.txt fixes and additions

> -----Original Message-----
> From: Randy Dunlap [mailto:[email protected]]
> Sent: Monday, May 07, 2018 2:50 AM
> To: [email protected]; axboe <[email protected]>
> Cc: LKML <[email protected]>; Caizhiyong
> <[email protected]>; Andrew Morton <[email protected]>;
> [email protected]; Jonathan Corbet <[email protected]>
> Subject: [PATCH] Documentation: block: cmdline-partition.txt fixes and
> additions
>
> From: Randy Dunlap <[email protected]>
>
> Make the description of the kernel command line option "blkdevparts"
> a bit more flowing and readable.
>
> Fix a few typos.
> Add the optional <size> and <offset> suffixes.
> Note that size can be "-" to indicate all of the remaining space.
>
> Signed-off-by: Randy Dunlap <[email protected]>
> Cc: Cai Zhiyong <[email protected]>
> ---
> Should the "ro" and "lk" flags options be described?

thank you for fix typos.
The "ro" and "lk" feature are not implemented in block devices. could you implement them?

> Documentation/block/cmdline-partition.txt | 21 +++++++++++++-------
> 1 file changed, 14 insertions(+), 7 deletions(-)
>
> --- linux-next-20180504.orig/Documentation/block/cmdline-partition.txt
> +++ linux-next-20180504/Documentation/block/cmdline-partition.txt
> @@ -1,7 +1,9 @@
> Embedded device command line partition parsing
>
> ==========================================================
> ===========
>
> -Support for reading the block device partition table from the command line.
> +The "blkdevparts" command line option adds support for reading the
> +block device partition table from the kernel command line.
> +
> It is typically used for fixed block (eMMC) embedded devices.
> It has no MBR, so saves storage space. Bootloader can be easily accessed
> by absolute address of data on the block device.
> @@ -14,22 +16,27 @@ blkdevparts=<blkdev-def>[;<blkdev-def>]
> <partdef> := <size>[@<offset>](part-name)
>
> <blkdev-id>
> - block device disk name, embedded device used fixed block device,
> - it's disk name also fixed. such as: mmcblk0, mmcblk1, mmcblk0boot0.
> + block device disk name. Embedded device uses fixed block device.
> + Its disk name is also fixed, such as: mmcblk0, mmcblk1, mmcblk0boot0.
>
> <size>
> partition size, in bytes, such as: 512, 1m, 1G.
> + size may contain an optional suffix of (upper or lower case):
> + K, M, G, T, P, E.
> + "-" is used to denote all remaining space.
>
> <offset>
> partition start address, in bytes.
> + offset may contain an optional suffix of (upper or lower case):
> + K, M, G, T, P, E.
>
> (part-name)
> - partition name, kernel send uevent with "PARTNAME". application can
> create
> - a link to block device partition with the name "PARTNAME".
> - user space application can access partition by partition name.
> + partition name. Kernel sends uevent with "PARTNAME". Application can
> + create a link to block device partition with the name "PARTNAME".
> + User space application can access partition by partition name.
>
> Example:
> - eMMC disk name is "mmcblk0" and "mmcblk0boot0"
> + eMMC disk names are "mmcblk0" and "mmcblk0boot0".
>
> bootargs:
> 'blkdevparts=mmcblk0:1G(data0),1G(data1),-;mmcblk0boot0:1m(boot),-
> (kernel)'

2018-05-08 15:34:57

by Jonathan Corbet

[permalink] [raw]
Subject: Re: [PATCH] Documentation: block: cmdline-partition.txt fixes and additions

On Sun, 6 May 2018 11:50:29 -0700
Randy Dunlap <[email protected]> wrote:

> Make the description of the kernel command line option "blkdevparts"
> a bit more flowing and readable.
>
> Fix a few typos.
> Add the optional <size> and <offset> suffixes.
> Note that size can be "-" to indicate all of the remaining space.
>
> Signed-off-by: Randy Dunlap <[email protected]>

Applied, thanks.

jon