If I recall correctly, WinCE runs drivers and system services in User mode, so any memory-mapped I/O would need to be set-up explicitly in the virtual address space. As Geert has pointed out, so long as it's in that first 512MB, a Linux driver running in Kernel mode can access it directly via Kseg1 (or Kseg0, if you wanted to be able to cache the data). ----- Original Message ----- From: "Suresh. R" <suresh@mistralsoftware.com> To: <linux-mips@linux-mips.org> Sent: Friday, January 16, 2004 8:32 Subject: VR4131 - MQ1132 - UPD63335 > Hi, > This might be a very basic question, but I am very new to this field. > So please help me. > > I am writing a linux device driver for UPD63335 audio codec. Its > controlled through the MQ1132 co-processor. The VR4131 is the processor. > The memory of MQ1132 is mapped to the processor memory in Kseg1 (0xA000 > 0000 onwards) which the manual says is TLB Unmapped region. Now my > question is is it necessary to map this region before using it in Linux. > Actually I have WinCE code for my reference. In that code the programmer > is mapping the region using Virtual Cpoy and Virtual Alloc. Is it > necessary to do that or Can I directly address the memory locatoin. > > Please help > > Thanks in advance > > Regards > Suresh > > >
