[U-Boot-Users] RTC for MPC5200
vwren at timension.com
Fri Jan 9 01:23:14 CET 2004
On Thu, Jan 08, 2004 at 11:56:52PM +0100, Wolfgang Denk wrote:
> What exactly is the problem? The procedure is fairly well documented
> in the DULG, and a ready-to-run image is supplied with the ELDK. Just
> boot it...
Oh, it boots, no problem. What I'm having trouble with (inexperience) is
changing the root filesystem after and cutting all ties to busybox so that
I can unmount the ramdisk. The closest I've gotten to booting is with
mount /dev/hda2 /mnt
pivot_root . /mnt/initrd
chroot . /etc/rc.sysinit <dev/console >dev/console 2>&1
But after that, I'm still running busybox, and when the "application" process
expires, it starts berating me. Of course, I can't umount /initrd because
it's still occupied. I've read up all I can find on the boot
process using initrd, and haven't found much specifics about handing over
control from one init process to another.
> A ramdisk image (loaded from flash) is one way to provide an embedded
> system that is 100% bullet-proof agains unexpected reboots or
Well, this does have a hard drive attached, so there will still be some
issues with filesystem recovery in case of accidents. I'm using this
more like a mini-server than an embedded system.
> Also, a more leaner setup like the busybox-based SELF used for our
> defualt ramdisk images boots much, much faster than the full-blown
> SysV init stuff.
It certainly does. My cable box should start so fast.
> You will not be judged by years of experience, or by any
> certificates. It's just the quality of the code that matters :-)
That's what worries me. :-) In my case, the years of experience were too
many years ago. Last time I did much low-level code munching was on my Atari
ST. MMUs were after my time.
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