On Thu, Oct 1, 2015 at 9:06 PM, Peter Crosthwaite <crosthwaitepe...@gmail.com> wrote: > On Wed, Sep 30, 2015 at 3:42 PM, Max Filippov <jcmvb...@gmail.com> wrote: >> On Thu, Oct 1, 2015 at 1:23 AM, Peter Crosthwaite >> <crosthwaitepe...@gmail.com> wrote: >>> On Wed, Sep 30, 2015 at 3:07 PM, Max Filippov <jcmvb...@gmail.com> wrote: >>>> On Thu, Oct 1, 2015 at 12:02 AM, Peter Crosthwaite >>>> <crosthwaitepe...@gmail.com> wrote: >>>>> Which makes MMU vs noMMU a board level property, not a CPU property. >>>>> It should appear in QEMU as such. >>>> >>>> Ok, one last try: can this property be queried from the selected CPU >>>> and passed to SoC initialization code? >>> >>> No, what I am trying to say is go the other way round. The property is >>> on the SoC, and it is used to select the CPU type. >> >> This is not what happens in reality. In reality the MMU type is the >> CPU property. >> A set of CPU properties comes from the outside along with the CPU name, and >> that's the only possible set of properties for this name. >> XTFPGA bitstream build scripts lay out its address space based on MMU >> type of the selected CPU. >> >> So let's make XTFPGA an SoC with a property that selects its address space >> layout. The machine (lx60/lx200/ml605/kc705) is configured with a CPU, > > So lx60/lx200 sound like isolated FPGA chips (Virtex 4 lx60?) while > ml605/kc705 are commonly available fully-featured FPGA dev boards.
Actually they're all fully-featured FPGA dev boards, from different times. lx60 and lx200 boards were produced by Avnet (yes, Virtex 4 based), ml605 and kc705 are from Xilinx. > Is lx60 short for a particular board featuring this part or is it more > abstract? Less memory, smaller onboard FLASH, different audio subsystem (not currently modeled). >> it >> queries MMU type from it and instantiates XTFPGA SoC with proper address >> space. That seems to be closest to what happens in reality. > > What is your intended user command lines? E.g. how do I boot with > ml605 no-mmu and then with mmu. '-M ml605 -cpu de108' will boot noMMU variant (de108 is not in the mainline yet, can be seen in the https://github.com/OSLL/qemu-xtensa/commits/xtensa-cores), '-M ml605 -cpu dc233c' will boot full MMU variant, as de108 doesn't have full MMU and dc233c does. -- Thanks. -- Max
