[U-Boot-Users] Linux kernel startup

[Harald Welte]

On Mon, Apr 07, 2008 at 02:31:10PM +0530, Tiju wrote:
> Hi Harald,
> 
> The serial issues were solved. As u said, the problem was with the
> RTS/CTS. I disabled all the hardware control signals and some
> modifications with the relocation section in the start.S and it
> started working.

great.

> Now the issue is with the kernel CRC32 check. I compiled a kernel with
> the smdk2440 architecture and I do the following.

Please see my other e-mail response about this.  I still believe there
might be some wrong memory / bus / core clock timing and or voltage
issues.  please try to use u-boot's built-in memory verification code to
veryify your memory before trying to boot a kernel on it.

What basically happens is that u-boot copies your kernel image from
storage medium to SDRAM, and then tries to checksum it.  If the original
image is correct, and the copy in SDRAM isn't, this means that you
somehow have memory corruption.

Is the hardware a prototype of a new board, or is it proven, verified
hardware?  If it's a new board, there can be dozens of different reasons
why the PLL might run instable, the power lines have too much noise,
etc.

Even if it's verified hardware, the particular PLL speed for memory or
CPU clock used by your u-boot image might not be within whatever your
hardware configuration supports.

So I would reconfigure all memory timings to their most conservative
(slowest) setting, and run the bus at 25 or 50MHz, the CPU core at
100MHz and re-try.  If the memory check and/or system boot works this
way, you can try to increase the timings incrementally up to your
desired configuration.

-- 
- Harald Welte <laforge at gnumonks.org>           http://laforge.gnumonks.org/
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