debugging ppc4xx VM w/ abatron

debugging ppc4xx VM w/ abatron

[Mark Pilon]

I know this has been addressed before -- I've searched this list
for the solution, and have read the manual ...

I'm trying to debug mvista's 2.4.2 kernel w/ the bdi2000 (v.1.05) and
am having trouble once the mmu is turned on -- I can set a
breakpoint in start_kernel(), gdb shows me the correct line
of source, but if I step-into or next-over the first call (a printk)
gdb (hhl 5.0) hangs -- I then break and it looks like I've taken
a bad fault ...:

(gdb) 1   <connect-to-target macro>
gdb_spin () at serial.c:5857
5857                 i++ ) {
(gdb) set gdb_spin_exit = 1
(gdb) p $pc
$1 = 0xc009b158
(gdb) b start_kernel
Breakpoint 1 at 0xc012f660: file init/main.c, line 534.
(gdb) c
Continuing.

Breakpoint 1, start_kernel () at init/main.c:534
534             printk(linux_banner);
(gdb) n

Program received signal SIGSTOP, Stopped (signal).
panic (fmt=0x0) at panic.c:100
100             for(;;) {
(gdb) where
#0  panic (fmt=0x0) at panic.c:100
#1  0xc0016694 in do_exit (code=0xb) at exit.c:438
#2  0xc0002bb4 in _exception (signr=0xc00f16bc, regs=0x0) at traps.c:86
#3  0xc000ccc0 in bad_page_fault (regs=0xc011ef30, address=0x0, sig=0xb)
    at fault.c:235
#4  0xc000cb94 in do_page_fault (regs=0xc011ef30, address=0xc011ef30,
    error_code=0x1030) at fault.c:186
#5  0xc0002980 in ret_from_except () at init/main.c:801
#6  0xc000d7ac in ioremap (addr=0x9030, size=0x0) at ioremap.c:148
#7  0xc0002334 in start_here ()
(gdb)

all construction suggestions appreciated,

Mark
--
Mark Pilon

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Re: debugging ppc4xx VM w/ abatron

[Dan Malek]

Mark Pilon wrote:

> I'm trying to debug mvista's 2.4.2 kernel w/ the bdi2000 (v.1.05) and
> am having trouble once the mmu is turned on

We have unfortunately really screwed up the Abatron folks lately by
moving around bits in the Linux PTEs.  I've tried to coordinate this
the best I can, to ensure we understand what kernel version matches
the BDI2000 firmware version.  Unfortunately, I'm not the only one
making changes, so sometimes I miss things.  I apologize and continue
to work with Abatron to sort this out.  It's the fault of us that are
making kernel modifications....

Oh sorry, the short answer is you need to patiently ask Abatron to
get the version of firmware that matches the kernel you are debugging.
By the way, this is only a 4xx problem.

Thanks.


	-- Dan

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