Hi wd, Thanks for the reply. Helped me a lot.
However see below On Thu, Jul 21, 2011 at 18:41:30, Wolfgang Denk wrote: > Dear "Hebbar, Gururaja", > > In message <c82ba3053cfd354aacbd25efbd2a4ec603f0193...@dbde02.ent.ti.com> you > wrote: > > > > > > The question here is mmc_args re-uses variable bootargs as > > $(bootargs) & nand_args re-uses it as ${bootargs}. Note the difference > > in curly & flower brackets. "run mmc_args" fails for me however > > nand_args runs properly. > > Does this not answer your question sufficiently? The point is mmc_args worked in one place & failed in other. After you reply, I found that the place where it worked was common shell environment & it was failing in Hush shell. > > > My question is > > 1. Which is correct? > > ${...} is correct. > > > 2. What is the difference between the two? > > ${...} is correct, and $(...) is not correct. > > > I have seen few boards using both methods. > > $(...) was used in very old versions of U-Boot, but this got changed for the > sake of compatibility with standard shell syntax. > > Note that the simple cmmand line parser still accepts the obsolete > $(...) format; the hush shell doesn't. > > 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: w...@denx.de A > morsel of genuine history is a thing so rare as to be always > valuable. - Thomas Jefferson > Regards, Gururaja _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot