Giuseppe Sacco wrote: > Hi Florian, > > Il giorno lun, 29/10/2007 alle 15.39 +0100, Florian Lohoff ha scritto: > [...] > > I guess xfsdump/restore use some interesting ioctl's which might > > need compat wrappers for the 32/64 bit case. But this is how its > > supposed to work. > > Thanks for this clarification, should this wrapper be in the userland > packages?
Compat ioctls would be implemented on the kernel side. IIRC they are just not implemented in the MIPS kernels, this is a feature missing upstream. > Should I bug the Debian xfsdump? Anyway, I still would like to > understand which are the reasons for providing a 64 bit kernel: is there > any ip32 system with more than 4Gb of memory? Is 64 bit required for > accessing some hardware stuff? Are there any other reason? On MIPS, the physical RAM limit of 32bit Kernels is the size of KSEG0 (512 MB), which typically hosts also some I/O devices. More than that need highmem. IP32 systems can have up to 2 GB RAM. The real killer, however, is the need to access 64bit wide registers atomically, implied by the hardware design. A 32bit kernel needs to disable/enable interrupts around each register access. The IP32 kernel used to be optionally 32bit or 64 bit, when it became too painful to maintain the 32bit support was dropped. Thiemo -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
