Thank you, Dan The problem is that it shares one global page table between kernel and application processes. Some of memory space that is allocated to each application process must be accessed by that application process. In other word, it must prevent an application process from accessing to memory space allocated to other an application process. For this protection, I need to use ASID. If memory space are marked as SHARED and suprevisor permission, kernel can access all of memory space because ASID checking is disabled. But it can't support memory protection for application processes.
I appreciate any your idea. Thank you so much. Okehee -----Original Message----- From: [EMAIL PROTECTED] [mailto:owner-linuxppc-embedded at lists.linuxppc.org]On Behalf Of Dan Malek Sent: Wednesday, October 24, 2001 9:01 PM To: Okehee Goh Cc: linuxppc-embedded at lists.linuxppc.org Subject: Re: MMU in MBX860 Okehee Goh wrote: > My question: > In MPC860, is there any way for supervisor mode's kernel to access all > memory space That's the purpose of the SHARED indicator in the TLB. It effectively disables ASID checking and if you mark pages SHARED but not user access the kernel can access all pages while the applications are still protected. -- Dan ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
