From: Wolfgang Denk <wd@denx.de>
To: u-boot@lists.denx.de
Subject: [U-Boot-Users] [patch] add support for "eeprom info"
Date: Thu, 24 Jan 2008 12:31:36 +0100 [thread overview]
Message-ID: <20080124113136.8DADF24788@gemini.denx.de> (raw)
In-Reply-To: Your message of "Thu, 24 Jan 2008 04:13:03 EST." <200801240413.04318.vapier@gentoo.org>
In message <200801240413.04318.vapier@gentoo.org> you wrote:
>
> > I think you are doing something wrong when you try to use "eeprom" to
> > access "SPI flash" - these are differnt entities...
>
> let's make sure we're talking about the same thing. SPI flashes are eeproms
> that have a SPI interface. so Spansion's S25FLxxxx, ST's m25pxtmels
> AT45DBxxxx, Winbond's W25Xxx/W25Pxx, and such. they need to be erased before
> writing, are split up into some unit size, etc... all SPI flashes nowadays
> conform to the JEDEC standard (JEP106) which allows for querying of
> manufacturer/device ids so that they can be dynamically detected. sounds to
> me like "eeprom" is the correct interface for utilizing these devices.
Sounds to me as if you were talking about flash devices with a SPI bus
interface.
The original SPI eeprom support was implemented som 7+ years ago for
the Siemens CCM board; this is where the "CONFIG_SPI" stuff in
common/cmd_eeprom.c comes from, and this was supported by the
cpu/mpc8xx/spi.c SPI driver. Note that this was a real EEPROM device,
i. e. we just needed spi_read() and spi_write() functions to access
it. No erase, no sectors or any such stuff.
That was an EEPROM - what you have looks like a flash device to me.
Best regards,
Wolfgang Denk
--
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
In the pitiful, multipage, connection-boxed form to which the flow-
chart has today been elaborated, it has proved to be useless as a
design tool -- programmers draw flowcharts after, not before, writing
the programs they describe. - Fred Brooks, Jr.
next prev parent reply other threads:[~2008-01-24 11:31 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-01-23 16:13 [U-Boot-Users] [patch] add support for "eeprom info" Mike Frysinger
2008-01-23 21:06 ` Wolfgang Denk
2008-01-23 21:15 ` Mike Frysinger
2008-01-23 21:23 ` Wolfgang Denk
2008-01-23 22:29 ` Mike Frysinger
2008-01-24 0:44 ` Wolfgang Denk
2008-01-24 3:39 ` Mike Frysinger
2008-01-24 4:24 ` Ben Warren
2008-01-24 5:17 ` Mike Frysinger
2008-01-24 11:13 ` Wolfgang Denk
2008-01-25 13:31 ` Mike Frysinger
2008-01-24 9:13 ` Mike Frysinger
2008-01-24 11:31 ` Wolfgang Denk [this message]
2008-01-25 13:33 ` Mike Frysinger
2008-01-25 15:09 ` Wolfgang Denk
2008-01-25 16:02 ` Mike Frysinger
2008-01-25 16:54 ` J. William Campbell
2008-01-25 17:21 ` Mike Frysinger
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=20080124113136.8DADF24788@gemini.denx.de \
--to=wd@denx.de \
--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 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.