[U-Boot-Users] U-Boot version string in kernel/userspace

[U-Boot-Users] U-Boot version string in kernel/userspace

[Gregoire Banderet]

Hi,

Waht's the best way to get the U-Boot version string (the one returned 
by U-Boot cmd "version") from userspace?
Arg passed to the kernel?
U-Boot env variables and use fw_getenv?
...?

-- Greg

[U-Boot-Users] U-Boot version string in kernel/userspace

[Timur Tabi]

Gregoire Banderet wrote:
> Hi,
> 
> Waht's the best way to get the U-Boot version string (the one returned 
> by U-Boot cmd "version") from userspace?
> Arg passed to the kernel?
> U-Boot env variables and use fw_getenv?

U-Boot disappears when the kernel loads, so the only cross-platform option is to 
pass a command-line parameter to the kernel.  Such a change would probably not 
be accepted into the mainline, however.

-- 
Timur Tabi
Linux kernel developer at Freescale

[U-Boot-Users] U-Boot version string in kernel/userspace

[Wolfgang Denk]

In message <479515A4.3080103@freescale.com> you wrote:
>
> > Waht's the best way to get the U-Boot version string (the one returned 
> > by U-Boot cmd "version") from userspace?
> > Arg passed to the kernel?
> > U-Boot env variables and use fw_getenv?
> 
> U-Boot disappears when the kernel loads, so the only cross-platform option is to 
> pass a command-line parameter to the kernel.  Such a change would probably not 
> be accepted into the mainline, however.

First, reading the kernel command line can be done in user space - no
need to change the kernel to do that.

Second, using the  command  line  is  not  the  only  way  to  access
envrionment  data.  Assuming  the  environment is stored in flash (or
similar), you can of course read (and write) it from Linux, too.

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
...when fits of creativity run strong, more than  one  programmer  or
writer  has  been  known to abandon the desktop for the more spacious
floor.                                             - Fred Brooks, Jr.

[U-Boot-Users] U-Boot version string in kernel/userspace

[Ben Warren]

Hi Gregoire,

On Jan 21, 2008 11:21 AM, Gregoire Banderet <Gregoire.Banderet@ge.com> wrote:
> Hi,
>
> Waht's the best way to get the U-Boot version string (the one returned
> by U-Boot cmd "version") from userspace?
> Arg passed to the kernel?
> U-Boot env variables and use fw_getenv?
> ...?
>
Yeah, I'd get it via the fw_getenv utility.  There's an environment
variable called 'ver', that should be accessible.  I say 'should',
because I've never looked at it before and don't currently have access
to a Linux-booted board to verify.  I have used fw_getenv/fw_setenv
extensively to read and write other variables and have never had any
problems.

regards,
Ben

[U-Boot-Users] U-Boot version string in kernel/userspace

[Andreas Schweigstill]

Hello!

Gregoire Banderet schrieb:
> Waht's the best way to get the U-Boot version string (the one returned 
> by U-Boot cmd "version") from userspace?
> Arg passed to the kernel?
> U-Boot env variables and use fw_getenv?

fw_getenv works fine for userspace programs. But I find it quite usefull
to forward U-Boot configuration parameters to Linux kernel space via
ATAGs, especially regarding different hardware versions and vice versa.
Accessing the data which has been provided by ATAGs can be very fast
because the ATAG data can be copied to global structures which can be
accessed by the kernel and also be kernel modules. Typical applications
are information about slightly different hardware versions, like GPIO
mapping or polarity.

With best regards
Andreas

-- 
Dipl.-Phys. Andreas Schweigstill
Schweigstill IT | Embedded Systems
Schauenburgerstra?e 116, D-24118 Kiel, Germany
Phone: (+49) 431 5606-435, Fax: (+49) 431 5606-436
Mobile: (+49) 171 6921973, Web: http://www.schweigstill.de/

[U-Boot-Users] U-Boot version string in kernel/userspace

[Wolfgang Denk]

In message <4795D957.1070305@schweigstill.de> you wrote:
> 
> fw_getenv works fine for userspace programs. But I find it quite usefull
> to forward U-Boot configuration parameters to Linux kernel space via
> ATAGs, especially regarding different hardware versions and vice versa.
> Accessing the data which has been provided by ATAGs can be very fast
> because the ATAG data can be copied to global structures which can be
> accessed by the kernel and also be kernel modules. Typical applications
> are information about slightly different hardware versions, like GPIO
> mapping or polarity.

I agree that this may make sense on ARM systems - to me it would also
make sense to pass the MAC address as an ATAG. The  problem  is  that
you  will  probably  run  into problems if youy try pushing such code
into the mainline kernel. RMK will likely block it.

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
"It ain't so much the things we don't know that get  us  in  trouble.
It's  the  things  we know that ain't so." - Artemus Ward aka Charles
Farrar Brown

[U-Boot-Users] U-Boot version string in kernel/userspace

[Robert Schwebel]

On Tue, Jan 22, 2008 at 02:47:48PM +0100, Wolfgang Denk wrote:
> I agree that this may make sense on ARM systems - to me it would also
> make sense to pass the MAC address as an ATAG. The  problem  is  that
> you  will  probably  run  into problems if youy try pushing such code
> into the mainline kernel. RMK will likely block it.

And for good reasons. He has explained it many times on alkml.

Robert
-- 
 Dipl.-Ing. Robert Schwebel | http://www.pengutronix.de
 Pengutronix - Linux Solutions for Science and Industry
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     Hannoversche Str. 2, 31134 Hildesheim, Germany
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