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Re: TS7200_INSTALL kernel problem solved - kernel too big!
"Patrick Collins" <normalbloke%gmail.com@localhost> writes:
: I think it would be great if we could have a very simple boot loader
: that could load a NetBSD kernel from CF. Do you think you could magic
: one of these please Jesse :)
It isn't terribly hard to write a smallish loader to do that. The
difficulty comes in generalizing it to run on a lot of different
platforms. Small size constraints limit how much you're able to write
good, modular code. The boot loader I wrote needed to know the memory
size so it could program the SDRAM controller with the right memory
geometry, which makes adaptation to other boards harder...
: Patrick Collins
: +61 419 712 581
: 2008/12/12 Jesse Off <joff%embeddedarm.com@localhost>:
: > 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
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