the blink-led does not random about(some gdb error)
xiangfu at openmoko.org
Fri Jun 13 09:09:21 CEST 2008
Werner Almesberger wrote:
> I would start with a tiny program that just blinks a LED. You boot
> this program from NAND (through Steppingstone), instead of u-boot.
> This will give you
> - a Makefile that you can understand completely
> - a good understanding of linking and compiler flags
> - knowledge how to access registers
> - experience with using u-boot (from NOR) to place your code into NAND
i add the code " turn off the watchdog ", then the led_on doesn't not
so i think i finish the first step.
> Then you can add full CPU initialization (start.S and friends) and
> gradually change this into the NAND loader, which loads a file from
> NAND to DRAM. I wouldn't try to use it to boot the kernel, but just a
> very simple program, such as that LED blinker (now running at a
> different address). This will give you
> - a good understanding of the CPU and DRAM bringup process
> - many opportunities to learn to use OpenOCD for debugging
> (you'll need this experience later to bring up the kernel)
on the other hand i try to add some code and follow the second step.
but when i use the
then following *GDB error* messages:
--arm-angstrom-linux-gnueabi-gdb: error while loading shared libraries:
libexpat.so.0: cannot open shared object file: No such file or directory
I google it but i can't find the answer.
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