redboot based boot loader for kernels?

[John Hay]

> : > Hi,
> : > 
> : > Does anyone have or is busy with an app that one can load in the
> : > redboot flash, that will load the kernel from the active partition
> : > of a compact flash? I know one can load the kernel in the redboot
> : > flash, but that makes remote upgrading more difficult. The way I
> : > have done with our wrap and soekris boards, is to create 2 slices
> : > on the CF. When upgrading, you just format and install on the
> : > non-active slice, change the active bit and reboot.
> : 
> : A certain someone promised to add read/write support for the flash.
> 
> That would be me...  My day job has been crazy and my new son isn't
> yet sleeping through the night.
> 
> : When that happens another option is to write the new kernel to flash
> : before rebooting.  Otherwise we need a redboot image that grok's ufs or
> : a secondary bootstrap that can be written to flash that knows how to
> : boot from cf (I recall the latter might be in the obsd thecus work).
> 
> The at91 boot2 groks ufs and only needs a function that can read the
> sectors from the underlying media to grok new media.  Of course, it
> inherited most of that from the i386 boot2.

Ok, I have it somewhat working for my Avila Gateworks board. I have
a bug somewhere in the code that do 16 bit reads from the CF, so for
now I have switched to 8 bit accesses. :-/ I'll search for that a
little later.

One thing that I would like to do is to pass the disk/slice info to
the kernel. The reason being that I have 2 FreeBSD slices and would
like the kernel to mount the one the boot loader tells it to. From
looking at how some of the other archs do it, it looks like I will
need some arm assembler foo. :-/ Anybody got ideas/code? I even
thought of compiling the kernel with "options ROOTDEVNAME" and then
the loader can load the kernel in ram and then search for the
ufs:ad0s1a string and twiddle it as appropriate, but that would not
work well with .gz.tramp kernels. :-)

John
-- 
John Hay -- John.Hay at meraka.csir.co.za / jhay at FreeBSD.org