Re: debugging ppc4xx VM, part 2

Wolfgang Denk wrote:

In message [ref] you wrote:

quoted

however, if I step or next, gdb never comes back; if I break out
and 'where' it looks like I've taken a fault ...

I think I've set everything up for mmu support in the bdi --
there was 1 statement in the user's manual to:
'If not automatically done by the kernel, setup the page table pointers
for the BDI.' -- I don't know from this what to check or what to do.

Well, did you (a) follow the description in the  BDI2000  manual  and
initialize  the  page  table  pointer  manually, or (b) did you use a
kernel which has the necessary extension to do it automagically?

Wolfgang Denk

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Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
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yes.

it looks like I've either got a gdb/bdi problem or a kernel build
problem:

in start_kernel() I've added a call gdb_spin() which simply spins,
waiting for a var to be set != 0 by gdb -- it gives me time to start
gdb and break in.  I can step / next in this function, returning to
start_kernel().

the next call is:
printk(linux_banner);

-- if I si twice, rc becomes set w/ a pointer to the format string
which looks reasonable.

the 3'rd si is the bl      0xc0012da4 <printk>
-- when I si to enter this func, and 'where' I get:
(gdb) where
#0  printk (fmt=0x32f050 <Address 0x32f050 out of bounds>) at printk.c:255
#1  0xc0002330 in start_here ()

-- no mention of the call from start_here() to start_kernel() -- and
printk's format ptr has become unreasonable.

tools & environment:
hhl-20 gdb for ppc405, ppc compiler which I've built; the target is
a custom mercury-based controller (405+FPU) and the abatron software
has been changed to work w/ this processor, but not heavily tested.
the rev of the 405-core used in the mercury is akin to a 405GP rev. C
which has some issues of its own.

the kernel is hhl-2.0 [2.4.2] for ppc405 which I'm attempting to get
running on this target.

["other than that, Mrs. Lincoln, how did you like the play?"]

has anyone seen anything like this kind of stack foulup w/
a simple bl?

I've used this debugger quite a bit w/o trouble debugging the boot/diags
package in real mode -- mmu off, no addr translation.

Mark


has anyone seen a probl
Mark





--
Mark Pilon

Minolta-QMS
P.O. Box 37
Fallon, MT.  59326-0037

1-406-853-0433

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