RE: BDI2000 PTEs

Thanks for reply, Dan

Rudolf Ladyzhenskii wrote:

quoted

..... At the moment I have memory translation enabled in BDI2000.
PTBASE is set to 0xf0 and this entry is cleared.

That's not correct.

quoted

.... This works for kernel
debugging, but memory translation fails when I try to do

dynamically loaded

quoted

module debugging.

All I need for kernel debugging is BAT only translation. I cleared it
according to BDI2000 manual.

quoted

I guess I have to set PTE pointers for BDI2000.

No, you don't.  Just use a newer kernel that has this feature
available for
all processors.  You could also copy the couple of lines of
code from a
newer kernel into your 2.4.4 if you insist.

I looked at 2.4.14 kernel. It only has BDI2000 support in file
/arch/ppc/kernel/head_8xx.S
8260 uses different file. I searched that for traces of Abatron or BDI2000
without success.
I also downloaded ppc patch for 2.4.14. Same: no trace of "abatron" or
BDI2000 there.

Which lines do I have to add?

Thanks,
Rudolf

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Rudolf Ladyzhenskii wrote:

All I need for kernel debugging is BAT only translation. I cleared it
according to BDI2000 manual.

Ummm....I think you need more than that for debugging loadable modules.
The BAT translation won't work for loadable modules, you have to find
all of their code and data through page tables.

I looked at 2.4.14 kernel. It only has BDI2000 support in file
/arch/ppc/kernel/head_8xx.S

Well hell....I wonder why they were never updated in 2.4.14.  Take
a look at the PowerPC development kernels, then.

Which lines do I have to add?

Add this right after the 'bl load_up_mmu':


        /* Add helper information for the Abatron bdiGDB debugger.
         * We do this here because we know the mmu is disabled, and
         * will be enabled for real in just a few instructions.
         */
        lis     r5, abatron_pteptrs@h
        ori     r5, r5, abatron_pteptrs@l
        stw     r5, 0xf0(r0)    /* This much match your Abatron config */
        lis     r6, swapper_pg_dir@h
        ori     r6, r6, swapper_pg_dir@l
        tophys(r5, r5)
        stw     r6, 0(r5)


Good Luck.


	-- Dan


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/