[U-Boot] setting u-boot params based on serial number
This may be bloody obvious to most of you, but I'm still learning.
I have a batch of boards in production.
say serial numbers 1 to 50
I want to set the 2 mac address, and the ip address so that the last few digits match the serial number.
can I do this easily with some sort of u-boot script? Or can I run an app I write myself in C or whatever, and get it to do setenv commands?
AVR32, if it matters
TVM
David Collier
www.dexdyne.com
David Collier wrote:
This may be bloody obvious to most of you, but I'm still learning.
I have a batch of boards in production.
say serial numbers 1 to 50
I want to set the 2 mac address, and the ip address so that the last few digits match the serial number.
can I do this easily with some sort of u-boot script? Or can I run an app I write myself in C or whatever, and get it to do setenv commands?
Yes
AVR32, if it matters
It shouldn't. You can do this any number of ways, but if it was me I'd script it off-target. I'm a big fan of Python, so tend to use pexpect for this sort of thing.
TVM
David Collier
regards, Ben
Dear "David Collier",
In message <memo.20091023175206.2092W@postmaster+dexdyne.com.cix.co.uk> you wrote:
I have a batch of boards in production.
say serial numbers 1 to 50
I want to set the 2 mac address, and the ip address so that the last few digits match the serial number.
can I do this easily with some sort of u-boot script? Or can I run an app I write myself in C or whatever, and get it to do setenv commands?
You can do this using the "setexpr" command, with the restriction that you cannot easily get leading zeros in the strings to fill tem up for the requested length, but for the usage you mention it does not matter. Also, you cannot easily convert to hex number, if that would be needed.
Example:
=> print serial# serial#=12851192
Extract last 2 digits into vatiable "tmp" (note: serial# must consist of digits only):
=> setex tmp ${serial#} % 100 => print tmp tmp=92
Set MAC and IP address as requested:
=> setenv ip_base 192.168.3. => setenv mac_base ce:94:6b:3a:db:
=> setenv ipaddr ${ip_base}${tmp} => print ipaddr ipxxx=192.168.3.92 => setenv ethaddr ${mac_base}${tmp} => print ethaddr ethaddr=ce:94:6b:3a:db:92
AVR32, if it matters
It does not matter. This works on all boards / architectures. You just have to enable CONFIG_CMD_SETEXPR in your board configuration.
Best regards,
Wolfgang Denk
Well I have got it working - but it seems to do exactly what you say it doesn't
for instance
LPNC U-Boot> printenv serialnumber serialnumber=410 LPNC U-Boot> setexpr sn34 ${serialnumber} / 2 LPNC U-Boot> printenv sn34 sn34=208
so it looks like it works ONLY in hex -
yup
a = simple_strtoul(argv[2], NULL, 16); b = simple_strtoul(argv[4], NULL, 16);
I'd like the decimal version like you described :-)
so I've defined setexprd to do that
David
wow
serialnumber=1234 set_mac_IP=setexprd sn34 ${serialnumber} % 100 ;setexprd sn12 ${serialnumber} / 100; setenv ipaddr 10.212.${sn12}.${sn34}; setenv ethaddr 00:90:46:20:${sn12}:${sn34}; setenv eth1addr 00:90:46:21:${sn12}:${sn34}; setenv sn12 ; setenv sn34
that's seriously useful!
TVM
David Collier
www.dexdyne.com
Dear "David Collier",
In message <memo.20091023213810.2092d@postmaster+dexdyne.com.cix.co.uk> you wrote:
serialnumber=1234 set_mac_IP=setexprd sn34 ${serialnumber} % 100 ;setexprd sn12 ${serialnumber} / 100; setenv ipaddr 10.212.${sn12}.${sn34}; setenv ethaddr 00:90:46:20:${sn12}:${sn34}; setenv eth1addr 00:90:46:21:${sn12}:${sn34}; setenv sn12 ; setenv sn34
that's seriously useful!
And it works the same when using "setexpr" ...
Best regards,
Wolfgang Denk
Dear "David Collier",
In message <memo.20091023211352.2092c@postmaster+dexdyne.com.cix.co.uk> you wrote:
Well I have got it working - but it seems to do exactly what you say it doesn't
Well, I'm not always right :-)
so it looks like it works ONLY in hex -
Makes sense. That's what semi-all commands do in U-Boot.
I'd like the decimal version like you described :-)
so I've defined setexprd to do that
I did not only describe it, I tested it. I just "tricked" a bit. You asked to extract the last two digits, and I used "% 100" to do this. Note that this works correctly in any number base - may it be 10 or 16 or whatever :-)
Hey, that was clever, wasn't it? :-)
Best regards,
Wolfgang Denk
I did not only describe it, I tested it. I just "tricked" a bit. You asked to extract the last two digits, and I used "% 100" to do this. Note that this works correctly in any number base - may it be 10 or 16 or whatever :-)
Hey, that was clever, wasn't it? :-)
yeah it was - but of course I really wanted the next 2 digits as well.... I'm hoping to make more than 100 units really! pardon me for over-simplifying my question.
I wonder if it would be useful/helpful to allow the user to optionally over-ride the number base for reading and separately for writing by setexpr.
That would extend it's usefulness without requiring an extra command or breaking any existing code
say
setenv setexpr_in 10 setenv setexpr_out 16
If I wrote a patch would you look favourably on it?
David
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@denx.de "Love is an ideal thing, marriage a real thing; a confusion of the real with the ideal never goes unpunished." - Goethe
David Collier
www.dexdyne.com
Dear "David Collier",
In message <memo.20091026103604.2092e@postmaster+dexdyne.com.cix.co.uk> you wrote:
I did not only describe it, I tested it. I just "tricked" a bit. You asked to extract the last two digits, and I used "% 100" to do this. Note that this works correctly in any number base - may it be 10 or 16 or whatever :-)
Hey, that was clever, wasn't it? :-)
yeah it was - but of course I really wanted the next 2 digits as well.... I'm hoping to make more than 100 units really! pardon me for over-simplifying my question.
Then do the same with "% 10000" and "/ 100" ?
I wonder if it would be useful/helpful to allow the user to optionally over-ride the number base for reading and separately for writing by setexpr.
I don't see a need for it; certainly not here.
That would extend it's usefulness without requiring an extra command or breaking any existing code
No extra command is needed here.
setenv setexpr_in 10 setenv setexpr_out 16
If I wrote a patch would you look favourably on it?
I don't think so. If we did something like that, it should be generic and not restricted to one command. And it would break a LOT of existing scripts. And it is not needed at all, at least not for the use case you have in mind here. [If anything is worth implementing at all, then maybe the regexp handling present in standard expr command.]
Best regards,
Wolfgang Denk
OK,
I concede I can indeed do the one thing I need here by using decimal values with hex arithmetic, and it will give the right answer.
though it is truly horrible coding :-)
I can see situations where I'd want to do something like "add one to the last serial number I used" where decimal arithmetic would be needed.
For myself, I don't see any reason why an arithmetic command shouldn't be a special case ( in having the option to work in various bases ), it's doing a special job.
Sorry it took me a while to catch onto your clever trick, and thanks for your help.
David
In article 20091026120130.9538128B9B@gemini.denx.de, wd@denx.de (Wolfgang Denk) wrote:
*From:* Wolfgang Denk wd@denx.de *To:* from_denx_uboot@dexdyne.com *CC:* u-boot@lists.denx.de *Date:* Mon, 26 Oct 2009 13:01:30 +0100
Dear "David Collier",
In message <memo.20091026103604.2092e@postmaster+dexdyne.com.cix.co.uk> you wrote:
I did not only describe it, I tested it. I just "tricked" a bit. You asked to extract the last two digits, and I used "% 100" to
do
this. Note that this works correctly in any number base - may
it be > 10 or 16 or whatever :-)
Hey, that was clever, wasn't it? :-)
yeah it was - but of course I really wanted the next 2 digits as well.... I'm hoping to make more than 100 units really! pardon me for over-simplifying my question.
Then do the same with "% 10000" and "/ 100" ?
I wonder if it would be useful/helpful to allow the user to optionally over-ride the number base for reading and separately for writing by setexpr.
I don't see a need for it; certainly not here.
That would extend it's usefulness without requiring an extra command or breaking any existing code
No extra command is needed here.
setenv setexpr_in 10 setenv setexpr_out 16
If I wrote a patch would you look favourably on it?
I don't think so. If we did something like that, it should be generic and not restricted to one command. And it would break a LOT of existing scripts. And it is not needed at all, at least not for the use case you have in mind here. [If anything is worth implementing at all, then maybe the regexp handling present in standard expr command.]
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@denx.de Testing can show the presense of bugs, but not their absence. -- Edsger Dijkstra
David Collier
www.dexdyne.com
Dear "David Collier",
In message <memo.20091026132928.2092l@postmaster+dexdyne.com.cix.co.uk> you wrote:
I concede I can indeed do the one thing I need here by using decimal values with hex arithmetic, and it will give the right answer.
though it is truly horrible coding :-)
You misunderstand. You misunderstand completly.
Exstracting the last N digits from a number using '%' is independent of the number base.
I can see situations where I'd want to do something like "add one to the last serial number I used" where decimal arithmetic would be needed.
Not for the addition itself :-)
For myself, I don't see any reason why an arithmetic command shouldn't be a special case ( in having the option to work in various bases ), it's doing a special job.
What probably would make sense and could be helpful for more advanced scripting is something like a sprintf command that would allow you to output (and store the result in a new environment variable) the content of one or more environment variables in a specific format, plus regexp support for setexpr.
Volunteers wellcome.
Best regards,
Wolfgang Denk
participants (3)
-
Ben Warren -
David Collier -
Wolfgang Denk