On Sat, Oct 03, 2015 at 02:31:08PM -0700, Peter Crosthwaite wrote: > QEMU cubieboard has no usable storage media, but the real hardware > does have AHCI sata. I added sysbus-ahci at the right place but turns > out the SATA controller has some custom power/clock (not really > sure??) registers specific to this SoC. It sets/clears bits then polls > them back expecting them to change to the other value asynchronously. > The kernel device probe then times-out. So I subclassed sysbus-ahci > and added the missing registers and forced the polled registers to the > "I'm done" state. It works.
Cool, are you going to submit patches for this? > I am using meta-sunxi Yocto-layer to build out the allwinner custom > kernel/rootfs etc, and with the clock and Sata changes I get a boot. > But when I change to the unedited kernel+dtb+rootfs I get stuck. RTC > messages are around the point of failure which is not modelled in > QEMU, so that is suspect. I don't know, this needs some investigation; on my side a recent multi_v7_defconfig kernel, unmodified sun4i-a10-cubieboard.dtb and a rootfs built with buildroot mounted through NFS work just fine, with the mentioned warnings regarding clk registers and also these: Ignoring attempt to switch CPSR_A flag from non-secure world with SCR.AW bit clear Ignoring attempt to switch CPSR_F flag from non-secure world with SCR.FW bit clear which probably would be solved by setting the property 'has_el3' of the CPU to false before realization. Beniamino
