[U-Boot-Users] Hush shell and simple calculations

[U-Boot-Users] Hush shell and simple calculations

[Antonio Di Bacco]

I don't manage to do some simple calculations like:

echo $((1+1))

Bye,
Antonio

[U-Boot-Users] Hush shell and simple calculations

[Wolfgang Denk]

In message <200605222214.38257.antonio.dibacco@aruba.it> you wrote:
> I don't manage to do some simple calculations like:
> 
> echo $((1+1))

That's true. This ain't no bash. Arithmetic expansion is not supported.

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
The computer can't tell you the emotional story. It can give you  the
exact mathematical design, but what's missing is the eyebrows.
- Frank Zappa

[U-Boot-Users] Hush shell and simple calculations

[Robin Gilks]

Antonio Di Bacco wrote:
> I don't manage to do some simple calculations like:
> 
> echo $((1+1))
> 
> Bye,
> Antonio

I've solved this with a new command 'eval' which is used to set a 
variable based on an expression. For example, I wanted to determine the 
start address of the kernel in flash for both 4 and 8meg parts but since 
its sits above U-Boot in the memory map (and U-Boot has to be 1M down 
from the top for high boot), it has to be calculated depending on the 
flash size. In this case, the new variable 'kb' contains the address of 
the beginning of the kernel of either 40340000 or 40740000 for either 4M 
or 8M devices.
     "eval kb $flash - c00c0000;"		\

This is work I did a couple of years ago and I'm no longer on the 
project so I'm not able to provide a 'formal' patch. To use it, put the 
file cmd_eval.c into ...uboot/common/ and make the following mods

in cmd_confdefs.h add
#define CFG_CMD_EVAL	0x0080000000000000U	/* Eval arithmetics             */

in your board config add
#define CONFIG_COMMANDS (   (    CONFIG_CMD_DFL \
                   ...............
                   | CFG_CMD_EVAL		\
		
in ..../uboot/common/Makefile
COBJS	= main.o ACEX1K.o altera.o bedbug.o \
           ............
	  cmd_eval.o

And that should be it.

I hope it helps...

-- 
Robin Gilks
Senior Design Engineer          Phone: (+64)(3) 357 1569
Tait Electronics                Fax  :  (+64)(3) 359 4632
PO Box 1645 Christchurch        Email : robin.gilks at tait.co.nz
New Zealand

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[U-Boot-Users] Hush shell and simple calculations

[Wolfgang Denk]

In message <44725285.1030006@tait.co.nz> you wrote:
> 
> I've solved this with a new command 'eval' which is used to set a 

I think that's a typo. An 'eval' command that does not behave exactly
as the standard shell 'eval' should have been named 'evil' ;-)


Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
The light at the end of the tunnel is usually a "No Exit" sign.

[U-Boot-Users] Hush shell and simple calculations

[Tolunay Orkun]

Wolfgang Denk wrote:
> In message <44725285.1030006@tait.co.nz> you wrote:
>> I've solved this with a new command 'eval' which is used to set a 
> 
> I think that's a typo. An 'eval' command that does not behave exactly
> as the standard shell 'eval' should have been named 'evil' ;-)

Maybe 'eval' is not the best name but lacking back tick capability it 
seems to me that you need to pass the name of (local?) environment 
variable to receive such assignment.

Perhaps we can add such functionality as another command (propose: iexpr)

I think I would really use this right now.

Best regards,
Tolunay

[U-Boot-Users] Hush shell and simple calculations

[Robin Gilks]

Wolfgang Denk wrote:
> In message <44725285.1030006@tait.co.nz> you wrote:
>> I've solved this with a new command 'eval' which is used to set a 
> 
> I think that's a typo. An 'eval' command that does not behave exactly
> as the standard shell 'eval' should have been named 'evil' ;-)

:-)

Since hush doesn't do many things that a ?standard? shell does I won't 
loose any sleep over it.

iexpr works for me...

-- 
Robin Gilks
Senior Design Engineer          Phone: (+64)(3) 357 1569
Tait Electronics                Fax  :  (+64)(3) 359 4632
PO Box 1645 Christchurch        Email : robin.gilks at tait.co.nz
New Zealand

=======================================================================
This email, including any attachments, is only for the intended
addressee.  It is subject to copyright, is confidential and may be
the subject of legal or other privilege, none of which is waived or
lost by reason of this transmission.
If the receiver is not the intended addressee, please accept our
apologies, notify us by return, delete all copies and perform no
other act on the email.
Unfortunately, we cannot warrant that the email has not been
 altered or corrupted during transmission.
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