[U-Boot-Users] Re: Interrupt management under PPC4xx platform
wd at denx.de
Mon Apr 14 18:03:02 CEST 2003
In message <126.96.36.199.0.20030414164127.01cb42e0 at 192.168.2.1> you wrote:
> I found a first problem in the trap_init function. Here is the situation
> before the instruction
> rlwinm r9, r7, 0, 18, 31:
> r7 = 0x7fce100
> CFG_MONITOR_LEN = 200*1024
If you look at the code, you will see that r7 was loaded from
GOT(_start), so it contains the entry point address of your image.
0x7fce100 seems a bit unlikely to me.
Here a couple of questions:
How did you #define CFG_MONITOR_BASE?
What's your TEXT_BASE?
How much RAM do you have on your system?
Which output is printed from the debug code in "lib_ppc/board.c"
(especially the "Now running in RAM - U-Boot at: xxx" line is of
> So r9, that contains the target address, is set to 0x2100 and consequently
> the vectors are placed starting from there.
> If change CFG_MONITOR_LEN to 192*1024 they are copied to the right place
> (0x100, anybody corrects me if I'm wrong) and the PIT interrupt is ok.
As you can read from the comments, the "rlwinm" instruction performs
the equivalent of the C expression "_start & 0x3FFF".
> With Ethereal I monitor the LAN traffic and I can see that the PC correctly
> answers to the ARP request. The SDRAM controller should be ok because I
> imported the initialization code from OpenBIOS. I suspect there are some
> slight differences in the Ethernet controller across the 405xx processors
> (I use a 405EP). I think I should investigate the Ethernet code. Where do
> you suggest me to start?
Please don't jump around. Let's fix one problem at a time.
Software Engineering: Embedded and Realtime Systems, Embedded Linux
Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd at denx.de
The software required `Windows 95 or better', so I installed Linux.
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