[U-Boot-Users] Debugging u-boot with BDI2000
jbeisert at eurodsn.de
Fri Jul 18 13:21:29 CEST 2003
>>I'm trying to debug my u-boot with BDI. It's a 405GP based system.
>> In the telnet sessoin I can insert "reset run" and u-boot starts. When I
>> enter "reset halt" and then "go" it won't do anything. I have tried with
>What do you mean with "it won't do anything"? Who won't do anything?
>The BDI2000? The CPU? What makes you think the CPU does not do
At first I thought the 405GP cpu does not start. On my card is a LED display,
so I can output some numbers very early in the startup process. With "reset
halt", "go" the display never change its contents, with "reset run" it does.
>Are you sure your BDI2000 config file is OK for your board?
Good question. What should happen, to be shure? I have debugged a running
Linux kernel with this configuration. So I think(!) the major settings are
> How did you configure "RESET type" and "STARTUP mode"? Is your
> "START address" ok?
RESET is not set, defaults to "SYSTEM"
STARTUP is set to RESET
START is set to 0x0000'0000 (readed from a default file)
With "reset halt", "info" I see the CPU waiting at address 0xFFFF'FFFC, after
one single step ("ti") it waits at address 0xFFFF'C0100. Seems ok.
>> When I step the mtmsr instruction ddd shows address 0x700, and the esr
>> register has 0x8800'0000 (illegal instruction occured?????).
>> Same when I place a breakpoint behind the mtmsr instruction und use "cont"
>> instead of "stepi".
>You are aware that you cannot single step through certain
>instructions, aren't you?
If the mtmsr instruction is not "single step able", it should run, if I place
a breakpoint behind this instruction (for example later in the C routines)
and use "go" to run up the breakpoint. Or not?
>> What is the difference between "reset run" and "reset halt", "go"?
>"reset run" and "reset halt" change the startup mode to "run" and
>"halt", respectively. "go" sets the PC and starts the target system.
>Ummm.. is there any specific part where the BDI2000 manual is unclear
Perhaps my english is very bad. Question was: Why the cpu is running normal
with "reset run", and did not run, when I enter "reset halt", enter a
breakpoint and than "go" (it never reaches the breakpoint).
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