[U-Boot-Users] Debugging U-Boot on 440GP
bpadalino at perigee.com
Thu Nov 27 01:02:45 CET 2003
I removed basically everything from the INIT section and have found (through
single stepping still .. I am not sure why later breakpoints still don't
work yet) where my system's red light comes on.
init_baudrate() calls getenv_r() -- since I do not have a valid environment
table, it uses the default. I modified my default environment to load the
baudrate first and it's during the envmatch() function that I end up getting
Even with baudrate at the beginning of the env table, it still falls through
everything to return(-1). I find that confusing, but the strange part is
that it returns to some place around 0x05?????? which is too high for my
32MB of DDR on the board.
I am guessing I have to look at the stack placement, but I ran out of time
today to look at that, so tomorrow I think I will look at the stack pointer
placement and if I am, for some reason or another, blowing it up.
I am still upset I can't set hardware breakpoints farther in code that I
know I can reach and use the 'c' command instead of single stepping through
it all. I am not setting too many breakpoints -- I keep it to the 2 that
the BDI supports.
So I suppose any extra help or pointers on the breakpoint situation would be
You know, I just realized -- why don't I just try to recompile u-boot to run
from RAM instead of trying to compile it and debug it to XIP?
Thanks for the help folks.
From: u-boot-users-admin at lists.sourceforge.net
[mailto:u-boot-users-admin at lists.sourceforge.net]On Behalf Of Wolfgang
Sent: Wednesday, November 26, 2003 9:51 AM
To: Brian Padalino
Cc: U-Boot Mailing List
Subject: Re: [U-Boot-Users] Debugging U-Boot on 440GP
in message <AKELKEJDICNMBGAOOBLAGEPACHAA.bpadalino at perigee.com> you wrote:
> Lastly, I was thinking about this last night -- is the BDI too invasive in
> trying to figure out if U-Boot will boot properly? It sets up the MMU and
> TLB by itself through it's init sequence, and I _think_ I am setting them
> properly in U-Boot, but I am not sure. From what I saw in the code in
I have often recommended to use just a MINIMAL inti script for the
BDI. Don't touch the memory controller. Just configure the absolute
necessary minimum (things like disabling a watchdog etc.).
> I guess I am just at a loss as to what these exception vectors mean
Then you will have to dig through a few books about the PowerPC
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