[U-Boot] [PATCH 5/5] New implementation for internal handling of environment variables.

[Kim Phillips]

On Tue, 20 Jul 2010 11:40:23 +0200
Wolfgang Denk <wd at denx.de> wrote:

> Dear Kim Phillips,
> 
> In message <20100719193825.120ebf29.kim.phillips at freescale.com> you wrote:
> >
> > > - It would be nice if we could add wildcard support for environment
> > >   variables; this is needed for variable name auto-completion,
> > >   but it would also be nice to be able to say "printenv ip*" or
> > >   "printenv *addr*"
> > 
> > you were right - a grepenv/findenv/'env search' substring
> > implementation on top of this looks to be at least as expensive as a
> > full export operation :/
> 
> Expensive in terms of what?  Code size? Probably not. It all boils
> down to running strstr() over all entries...

time I thought, but ok, I'll look into it when I have time.

> As you can see, there are stages where the new code is a bit slower
> (20...40 milliseconds, which is close to the resolution of the
> measurement), but in this specific test we win some 280 milliseconds;
> if you exclude the 5 seconds boot delay that's some 2.7%. I don't
> think it's worth mentioning, but at least it's not worse than the old
> code.

excellent, thank you.

> I haven't tested many boards, especially not for timing. If you have
> additional input it will be welcome.

I would, however u-boot-testing.git/hashtable currently fails to boot
on an 8572:

U-Boot 2010.06-02552-g9895ea5 (Jul 19 2010 - 18:39:19)

CPU0:  8572E, Version: 1.1, (0x80e80011)
Core:  E500, Version: 3.0, (0x80210030)
Clock Configuration:
       CPU0:1499.985 MHz, CPU1:1499.985 MHz, 
       CCB:599.994 MHz,
       DDR:399.996 MHz (799.992 MT/s data rate) (Asynchronous), LBC:37.500 MHz
L1:    D-cache 32 kB enabled
       I-cache 32 kB enabled
Board: MPC8572DS Sys ID: 0x14, Sys Ver: 0x30, FPGA Ver: 0x10, vBank: 0
I2C:   ready
DRAM:  Initializing....

I presume it's related to the issue brought up in this thread?:

http://lists.denx.de/pipermail/u-boot/2010-July/074151.html

Cheers,

Kim