I've built a simple hello for RISC-V. It runs in Spike as expected. In QEMU it doesn't run. It stops at loading the kernel in elfloader/src/common.c at the lines below: 199 printf("ELF-loading 199\n"); 200 /* Copy the data. */ 201 unpack_elf_to_paddr(elf, dest_paddr); I'd really like to use QEMU/GDB to debug my kernel. Can anyone shed some light on what's happening here? The failed output from QEMU looks like this: user@user-KVM:/mnt/data/femur/build$ qemu-system-riscv64 --machine spike --nographic --bios images/hello-image-riscv-spike bbl loader ELF-loader started on paddr=[80200000..802fb90f] ELF-loading image 'kernel' paddr=[c0000000..c0026fff] vaddr=[ffffffff80000000..ffffffff80026fff] virt_entry=ffffffff80000000 ELF-loading 187 ELF-loading 195 ELF-loading 199 The output from spike is the same but complete: ser@user-KVM:/mnt/data/femur/build$ /mnt/data/rocket-tools/bin/spike images/hello-image-riscv-spike bbl loader ELF-loader started on paddr=[80200000..802fb90f] ELF-loading image 'kernel' paddr=[c0000000..c0026fff] vaddr=[ffffffff80000000..ffffffff80026fff] virt_entry=ffffffff80000000 ELF-loading 187 ELF-loading 195 ELF-loading 199 ELF-loading 203 ELF-loading 211 ELF-loading image 'hello' paddr=[c0027000..c013afff] vaddr=[10000..123fff] virt_entry=10216 ELF-loading 187 ELF-loading 195 ELF-loading 199 ELF-loading 203 ELF-loading 211 Jumping to kernel-image entry point... Booting all finished, dropped to user space hello, world! Warning: using printf before serial is set up. This only works as your printf is backed by seL4_Debug_PutChar() hrintf is bac seL4 root server abort()ed Debug halt syscall from user thread 0xffffffc0bffd8a00 "rootserver" halting...Power off