[U-Boot] hush while confusion

[David Collier]

sorry - my fault - I failed to grasp the meaning of itest

This now works

while itest 1 == 1 ; do ; mmcinit && ext2load mmc 0:1 0x10400000
/boot/uImage && bootm 0x10400000 ; done

I could do with a literal "true" - I tried 'true' but that wasn't right -
is there a suitable constant value?

I'd still love to find some teaching stuff on this - I can't keep
bothering important people like you :-)

David

In article <memo.20091022142208.2092E at postmaster+dexdyne.com.cix.co.uk>,
from_denx_uboot at dexdyne.com (David Collier) wrote:

> *From:* "David Collier" <from_denx_uboot at dexdyne.com>
> *To:* u-boot at lists.denx.de
> *Date:* Thu, 22 Oct 2009 14:22 +0100 (BST)
> 
> OK I have changed it to
> 
> while 1==1 ; do ; mmcinit && ext2load mmc 0:1 0x10400000  
> /boot/uImage &&
> bootm 0x10400000 ; done
> 
> and if I do run bootcmd it simply says "unknown command 1==1"
> 
> so I'm still lost....
> 
> I know I have hush installed, cosz if I do your multi-line-version 
> I get
> the prompt.
> 
> ------------------------------------------------------------
> 
> All I saw about hush was "bourne-compatible", and "provides
> while...do..done" scripting.
> 
> I failed to find a proper manual... probably for lack of effort, 
> but I've
> just googled again and nothing springs up..
> 
> Could you possibly point me at any hush documentation ?
> 
> Many thanks
> 
> David 
> 
> 
> In article <20091022113139.DB6961A00B at gemini.denx.de>, wd at denx.de
> (Wolfgang Denk) wrote:
> 
> > *From:* Wolfgang Denk <wd at denx.de>
> > *To:* from_denx_uboot at dexdyne.com
> > *CC:* u-boot at lists.denx.de
> > *Date:* Thu, 22 Oct 2009 13:31:39 +0200
> > 
> > Dear "David Collier",
> > 
> > In message 
> > <memo.20091022093854.2092B at postmaster+dexdyne.com.cix.co.uk> you 
> > wrote:
> > > 
> > > what I'd like to do is put it in a while loop - this is an 
> > > embedded
> > > system and it has nothing better to do than to try again.
> > > 
> > > but if I set up 
> > > 
> > > bootcmd=while [ .... ]; do ; mmcinit && ext2load mmc 0:1 
> > > 0x10400000
> > > /boot/uImage && bootm 0x10400000 ; done
> > > 
> > > no matter what I have put in or around the [..] area, it barfs.
> > 
> > Did you understand why it barfs? The '[' is actually a command 
> > name,
> > which usually is a synonym for the 'test' command. U-Boot does not
> > provide such a coimmand, and the hush shell does not provide it as
> > shell builtin either, so this _must_ fail.
> > 
> > I am surprised that you did not find this out yourself - U-Boot 
> > should
> > issue a pretty clear error message, something like
> > 
> > 	Unknown command '[' - try 'help'
> > 
> > > Could anyone show me a working example of a hush while loop 
> > > please? Or
> > > tell me what I'm doing wrong :-)
> > 
> > Here is a (tested and working) example:
> > 
> > 	=> mw 200000 0
> > 	=> while itest *200000 == 0 ; do
> > 	> tftp 200000 tqm5200/uImage
> > 	> echo === done ====
> > 	> done
> > 	Using FEC ETHERNET device
> > 	TFTP from server 192.168.1.1; our IP address is 192.168.160.4
> > 	Filename 'tqm5200/uImage'.
> > 	Load address: 0x200000
> > 	Loading: 
> > #################################################################
> > 	         
> > ############################################################
> > 	done
> > 	Bytes transferred = 1830503 (1bee67 hex)
> > 	=== done ====
> > 	=> 
> > 
> > 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
> > "Where shall I begin, please your Majesty?" he asked. "Begin  at  
> > the
> > beginning,"  the  King said, gravely, "and go on till you come to 
> > the
> > end: then stop."    - Alice's Adventures in Wonderland, Lewis 
> > Carroll
> > 
> 
> 
> Collier
> 
> www.dexdyne.com
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> 


Collier

www.dexdyne.com