On Mon, 26 Sept 2022 at 20:39, Victor Martins <[email protected]> wrote: > And after I try use the dtb file and remove the virt board like this: > > $ qemu-system-riscv64 \ > -nographic \ > -dtb ./riscv64-virt.dtb \ > -kernel linux-5.19.1/arch/riscv/boot/Image \ > -append "root=/dev/vda ro console=ttyS0" \ > -drive file=busybox,format=raw,id=hd0 \ > -device virtio-blk-device,drive=hd0 \ > -netdev user,id=eth0 \ > -device virtio-net-device,netdev=eth0
This command doesn't specify a machine type. That means you get whatever the default machine type for riscv64 is, which happens to be "spike". A kernel built for the "virt" board won't run on "spike", especially if it's passed a DTB for the "virt" board. What are you trying to achieve by removing the "-machine virt" option? In general: (1) you should always specify a machine type (even if there is a default, it's clearer to say what you want rather than relying on the default) (2) the guest kernel you pass should be built with support for that machine type (3) for machine types that automatically generate a DTB file, you should just let QEMU autogenerate and pass the DTB file; don't use the "-dtb" option on these machines > But don't work as before and I get this error: > > $ qemu-system-riscv64: -device virtio-blk-device, > > drive=hd0: No `virtio-bus´ bus found for device `virtio-blk-device´ This is because "spike" doesn't support virtio. > I feel that the dump operation dont extract the full Device > Tree. My idea is to try to use only the dtb/dts. Is that possible? -dumpdtb is giving you the complete device tree, but you seem to be confused about what QEMU does with the -dtb option. All QEMU does with the dtb file you provide is give it to the kernel you boot. The dtb file does not cause QEMU in any way to change what kind of hardware it is emulating. (dumpdtb is intended largely for debugging, so you can see what the dtb passed to the guest kernel is; there are also some rare use cases where you might want to edit it and then pass it back to QEMU. 99% of users don't need it at all.) thanks -- PMM
