In fact, even Windows XP SP2 and later had to enable PAE with physical address space limited to 4GB in order to enable NX.
32-bit GNU Mach is limited to 1 GB of memory, so NX and Xen support are the only uses for PAE on 32-bit GNU Mach. To actually address more than 1 GB GNU Mach will need to be ported to 64-bit (which can sttill run with a 32-bit userspace), or something similar to Linux's HIGHMEM will need to be added. Yuhong Bao ---------------------------------------- > Date: Sun, 15 Mar 2009 23:19:15 +0100 > From: samuel.thiba...@ens-lyon.org > To: yuhongbao_...@hotmail.com > CC: bug-hurd@gnu.org > Subject: Re: NX support in GNU Mach > > Hello, > > Yuhong Bao, le Fri 13 Mar 2009 12:14:56 -0700, a écrit : >> I heard that PAE support has been recently implemented in GNU Mach. > > Yep. > >> I think the next step is to add No-Execute (NX) support to GNU Mach. > > Oh, that could be useful indeed. The good news is that the user/kernel > interface already exists: VM_PROT_EXECUTE, it's just not implemented > yet within gnumach.. > > >> I'd also suggest adding support for more then 4 GB of RAM to GNU Mach, but >> considering that it does not even support more than 1 GB of RAM yet, I'd fix >> that before trying to support more than 4 GB of RAM. And it is IMO important >> to >> fix, because most of today's PCs have more than 1 GB of RAM, especially >> thanks >> to Vista. > > It'd be probably better to just support 64bit processors, which will > immediately bring support for more than 1GB of RAM. Support for more > than 1GB of RAM on a 32bit machine is really clumsy. Linux does it, but > it's really a pain. > >> Also important IMO is ACPI support, which will help when implementing >> SMP support. > > Well, the ACPI part for SMP shouldn't be so hard ; SMP itself will be. > > Samuel _________________________________________________________________ Lauren found her dream laptop. Find the PC that’s right for you. http://www.microsoft.com/windows/choosepc/?ocid=ftp_val_wl_290
