Problem about running hello world example

[kaichieh0524]

I am trying to run the hello world example on the qemu platform. The followings steps I tried

• Build the qemu binary by the instruction as this READ.ME https://github.com/lowRISC/qemu/blob/ot-9.2.0/docs/opentitan/index.md

Next, I clone the github repo from OpenTitan github https://github.com/lowRISC/opentitan
Then I build the example by command

bazel build //sw/device/exmpales/hello_world

Finally,

qemu-system-riscv32 -M ot-earlgrey,no_epmp_cfg=true -display none -serial mon:stdio -kernel hello_world_fpga_cw310.elf

But there is no any string like "hello world" show on my console... Is there any more detail about how to build the hello.elf mentioned in https://github.com/lowRISC/qemu/blob/ot-9.2.0/docs/opentitan/earlgrey.md? Or there is somethin I missing?