From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: chrp mmu and booting. From: Benjamin Herrenschmidt To: Peter Bergner Cc: Sven Luther , linuxppc-dev list In-Reply-To: <1074890984.2840.25.camel@otta.rchland.ibm.com> References: <20040123111725.GB23537@iliana> <1074883450.2842.9.camel@otta.rchland.ibm.com> <20040123185433.GB5125@iliana> <1074890984.2840.25.camel@otta.rchland.ibm.com> Content-Type: text/plain Message-Id: <1074906380.814.49.camel@gaston> Mime-Version: 1.0 Date: Sat, 24 Jan 2004 12:06:21 +1100 Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: On Sat, 2004-01-24 at 07:49, Peter Bergner wrote: > In real mode, there is no address mapping done. When the kernel starts > executing, we are not loaded where we were linked at, so we must be very > careful about what we touch. You'll see in arch/ppc64/kernel/prom.c, > that we use the RELOC() macro to access global data. It essentially > maps the virtual/effective address the kernel expects things to be at > to the physical address it's actually loaded at. The ppc32 kernel was > able to remove the RELOC() macro, but for various reasons, the PPC64 > kernel is still stuck using it. Yup :( Anton, Paulus and I have been scratching our heads to find a way to kill it, not as simple as ppc32 but we'll eventually do it :) Ben. ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/