From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [RFC:PATCH 00/03] powerpc: Expose BookE debug registers through extended ptrace interface Mime-Version: 1.0 (Apple Message framework v1077) Content-Type: text/plain; charset=us-ascii From: Kumar Gala In-Reply-To: <20091210155709.6697.4635.sendpatchset@norville.austin.ibm.com> Date: Thu, 10 Dec 2009 20:45:02 -0600 Message-Id: References: <20091210155709.6697.4635.sendpatchset@norville.austin.ibm.com> To: Dave Kleikamp Cc: linuxppc-dev list , Sergio Durigan Junior , Torez Smith , Thiago Jung Bauermann , David Gibson List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Dec 10, 2009, at 9:57 AM, Dave Kleikamp wrote: > These patches implement an extention to the ptrace interface proposed = by > Thiago Bauermann and the the PowerPC gdb team. >=20 > GDB intends to support the following hardware debug features of BookE > processors: >=20 > 4 hardware breakpoints (IAC) > 2 hardware watchpoints (read, write and read-write) (DAC) > 2 value conditions for the hardware watchpoints (DVC) >=20 > For that, we need to extend ptrace so that GDB can query and set these > resources. Since we're extending, we're trying to create an interface > that's extendable and that covers both BookE and server processors, so > that GDB doesn't need to special-case each of them. We propose the > following 3 new ptrace requests described below. >=20 > There have been discussions of a generic hardware debug interface for = the > kernel which would hopefully contemplate all the functionality below = and > supersede it. But we need something that works now, and which enables = GDB > to be simpler and work with both Server and Embedded processors = without > special cases. What do we do in EDM mode? We need a flag somewhere to determine if HW = supports conveying DBCR0[EDM] and if it does which of the ptrace calls = fails? - k=