From: Tom Rini <trini@konsulko.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCHv3 3/4] spl: Lightweight UBI and UBI fastmap support
Date: Tue, 12 Jan 2016 21:39:06 -0500 [thread overview]
Message-ID: <20160113023906.GZ3359@bill-the-cat> (raw)
In-Reply-To: <20160110231728.GC5338@localhost.localdomain>
On Mon, Jan 11, 2016 at 12:17:28AM +0100, Ladislav Michl wrote:
> From: Thomas Gleixner <tglx@linutronix.de>
>
> Booting a payload out of NAND FLASH from the SPL is a crux today, as
> it requires hard partioned FLASH. Not a brilliant idea with the
> reliability of todays NAND FLASH chips.
>
> The upstream UBI + UBI fastmap implementation which is about to
> brought to u-boot is too heavy weight for SPLs as it provides way more
> functionality than needed for a SPL and does not even fit into the
> restricted SPL areas which are loaded from the SoC boot ROM.
>
> So this provides a fast and lightweight implementation of UBI scanning
> and UBI fastmap attach. The scan and logical to physical block mapping
> code is developed from scratch, while the fastmap implementation is
> lifted from the linux kernel source and stripped down to fit the SPL
> needs.
>
> The text foot print on the board which I used for development is:
>
> 6854 0 0 6854 1abd
> drivers/mtd/ubispl/built-in.o
>
> Attaching a NAND chip with 4096 physical eraseblocks (4 blocks are
> reserved for the SPL) takes:
>
> In full scan mode: 1172ms
> In fastmap mode: 95ms
>
> The code requires quite some storage. The largest and unknown part of
> it is the number of fastmap blocks to read. Therefor the data
> structure is not put into the BSS. The code requires a pointer to free
> memory handed in which is initialized by the UBI attach code itself.
>
> See doc/README.ubispl for further information on how to use it.
>
> This shares the ubi-media.h and crc32 implementation of drivers/mtd/ubi
> There is no way to share the fastmap code, as UBISPL only utilizes the
> slightly modified functions ubi_attach_fastmap() and ubi_scan_fastmap()
> from the original kernel ubi fastmap implementation.
>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
--
Tom
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 836 bytes
Desc: Digital signature
URL: <http://lists.denx.de/pipermail/u-boot/attachments/20160112/39a9a5d7/attachment.sig>
next prev parent reply other threads:[~2016-01-13 2:39 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-10 23:14 [U-Boot] [PATCHv3 0/4] spl: Lightweight UBI and UBI fastmap support Ladislav Michl
2016-01-10 23:15 ` [U-Boot] [PATCHv3 1/4] mtd: Sort subsystem directories aplhabeticaly in Makefile Ladislav Michl
2016-01-13 2:38 ` Tom Rini
2016-01-10 23:16 ` [U-Boot] [PATCHv3 2/4] nand_spl_simple: Add a simple NAND read function Ladislav Michl
2016-01-13 2:39 ` Tom Rini
2016-01-10 23:17 ` [U-Boot] [PATCHv3 3/4] spl: Lightweight UBI and UBI fastmap support Ladislav Michl
2016-01-11 6:14 ` Heiko Schocher
2016-01-13 2:39 ` Tom Rini [this message]
2016-01-10 23:18 ` [U-Boot] [PATCHv3 4/4] igep00x0: UBIize Ladislav Michl
2016-01-11 6:20 ` Heiko Schocher
2016-01-11 12:58 ` Ladislav Michl
2016-01-12 9:08 ` Heiko Schocher
2016-01-12 22:17 ` Ladislav Michl
2016-01-13 5:09 ` Heiko Schocher
2016-01-12 23:24 ` Ladislav Michl
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20160113023906.GZ3359@bill-the-cat \
--to=trini@konsulko.com \
--cc=u-boot@lists.denx.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox