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 C82BA3053CFD354AACBD25EFBD2A4EC603F0193C2D@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
- Which is correct?
${...} is correct.
- 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: wd@denx.de A morsel of genuine history is a thing so rare as to be always valuable. - Thomas Jefferson
Regards, Gururaja