Re: deciphering powerpc registers
Re: deciphering powerpc registers
- Subject: Re: deciphering powerpc registers
- From: Justin Walker <email@hidden>
- Date: Thu, 13 Mar 2003 11:32:05 -0800
On Thursday, Mar 13, 2003, at 10:42 US/Pacific, Brian Bergstrand wrote:
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
On Thursday, March 13, 2003, at 12:03 PM, Brian Daugherty wrote:
PC = Program Counter. This is actually r2 (I think) since the PPC does
not actually have a PC register.
Whereever the PC may be, it's not r2, which is a general-purpose
register, available for any use (ignoring the ABI, of course). The PC
is not accessible, but it's there in some form, internally.
DAR = Data register, this is usually r3, or the first arg to a function
call.
No, again, r3 is a general-purpose register. This one (DAR) is the
Data Address Register (kernel-accessible) that contains the address
that caused a Data Access fault.
LR = Link Register which should be the previous function in the call
stack.
It contains the address to return to after a procedure call (bl, ==
'branch and link'); or contains the target of one of the
"branch-to-link-register" instructions.
I forget what MSR and DSISR are.
Machine State Register and Data Storage/Instruction Storage Register.
Regards,
Justin
--
Justin C. Walker, Curmudgeon-At-Large *
Institute for General Semantics | If you're not confused,
| You're not paying attention
*--------------------------------------*-------------------------------*
_______________________________________________
darwin-kernel mailing list | email@hidden
Help/Unsubscribe/Archives:
http://www.lists.apple.com/mailman/listinfo/darwin-kernel
Do not post admin requests to the list. They will be ignored.