Ken Hornstein wrote:
u-boot has those features now, but not redboot.
Yeah, I think that unless Embedded ARM wants to switch to u-boot, that
doesn't
help us. Ah, well.
--Ken
We're not a big fan of either u-Boot or RedBoot out here. Seems like
overkill to write one OS to for the sole purpose of starting up another. I
personally prefer to minimize how many drivers I write or debug for the same
hardware. :-)
In our new products, we have written a 442 byte bootloader that loads
kernels from x86 MBR style partitions of either NAND flash or SD card and
can boot a small Linux kernel + ramdisk in about the same amount of time it
takes the RedBoot or u-boot bloatware to start up. Once up, we have written
a Linux program + kernel module that can start up other OS's, RTOS's, and
OS-less applications. In effect, we use Linux as our bootloader so that you
could load kernels via NFS over USB wifi dongle and configure pre-bootup
behavior in shell script, etc...
Here's some info on it:
http://www.embeddedarm.com/software/arm-linux-bootloader.php
I ported the bootload utility to NetBSD too-- it doesn't even need a kernel
module. I do what I need to do there via /dev/mem and /dev/kmem.
This application + kernel module should also work on the default TS-7200
Linux installation. You can place the NetBSD kernel on the Linux JFFS2
filesystem and then run our "bootload" command to soft-boot into another OS.
On the platforms we've standardized on this scheme we can go from power-on
to Linux to another OS in about 3 seconds or so. The TS-7200 Linux boots up
a little slower, but its still not too bad.
//Jesse Off