[U-Boot-Users] u-boot debugging using gdb and BDI2000

[Demke, Torsten]

Thanks for the hint Carolyn, I made some progress but...

When I map my flash using MMAP I can now debug code 
in flash using BDI/gdb. But I cannot access the SDRAM - 
bdi returns "#invalid argumet" for any SDRAM address.
If I also MMAP may SDRAM region I can access/run/debug code from
flash and SDRAM but only using BDI. When attaching gdb I loose
access to flash and SDRAM, like without any MMAP command.

(The same behaviour occurs after BDI start, when I access some
SDRAM addresses in BDI. Because SDRAM access is not yet initialized
it is an error(somehow), but also flash is not accessible 
after that (return all "0")).

I guess that the gdb (when attaching to BDI/target) is accessing
some invalid memory region -> access to all memory/flash is lost.
I only flash is MMAPed the invalid access is hidden and I can debug
code in flash.
Question: What memory is accessed by gdb (when connecting to BDI) that
is not yet initialized?

Thanks,
Torsten





> -----Original Message-----
> From: carolyn.j.smith at exgate.tek.com
> [mailto:carolyn.j.smith at exgate.tek.com]
> Sent: Mittwoch, 2. Juli 2003 21:56
> To: Torsten.Demke at fci.com
> Cc: u-boot-users at lists.sourceforge.net
> Subject: RE: [U-Boot-Users] u-boot debugging using gdb and BDI2000
> 
> 
> I have recently been going through this same problem. I also 
> have a working
> U-Boot so I didn't bother with any DRAM initialization in my 
> BDI2000 config
> file but found I couldn't see my boot ROM code or get the 
> target started
> properly from the BDI2000.
> 
> The key for me ended up being the MMAP command to get access 
> to the boot ROM
> address range. For example
> 
> MMAP 0xFFF00000 0xFFF7FFFF
> 
> Once I had that I could see the U-Boot code again using 'md 
> 0xfff00100' and
> start the target running using 'go'.
> 
> Hope this helps.
> 
> Carolyn
> 
> >-----Original Message-----
> >From: Demke, Torsten [mailto:Torsten.Demke at fci.com] 
> >Sent: Tuesday, July 01, 2003 10:06 AM
> >To: U-Boot Mailing List (E-mail)
> >Subject: [U-Boot-Users] u-boot debugging using gdb and BDI2000
> >
> >
> >Hallo all,
> >
> >we recently purchased a BDI2000 to debug some of our products.
> >I have u-boot-0.4.0 running on our board with a MPC8245. For
> >a first test I connected the BDI2000 and at the telnet window a can
> >see the u-boot code (md 0xfff00100) and can single-step through it.
> >1) general question:
> >I removed DRAM etc initialization from the config. file because 
> >it will be initialized from the u-boot code. Will it work that 
> >way or is
> >DRAM
> >access needed for proper work of BDI2000/gdb?
> >2) Problem:
> >Now I start the gdb and attach it to the BDI2000 
> >((gdb) target remote bdi:2001)
> >After that I cannot see the code in flash anymore - md command in 
> >telnet window returns all "0". Disassemble in gdb also 
> returns all "0".
> >What did I make wrong?
> >
> >Thanks for your help.
> >Torsten
> >
> >
> >
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