Add qemu support for Lagarto Ox

The network is still not working automatically, but the eth0 device is
present in the host.

Reviewed-by: Rodrigo Arias Mallo <rodrigo.arias@bsc.es>

boot.sh

@@ -27,7 +27,7 @@ fi
 # Create a directory for exchanging data with the VM.
 mkdir -p "$TMPDIR/xchg"
 
-system="$NIXOS_SYSTEM_TOPLEVEL"
+system="$TOPLEVEL"
 echo "Booting $system"
 
 cd "$TMPDIR"
@@ -37,7 +37,7 @@ cd "$TMPDIR"
 #QEMU_KERNEL_PARAMS="boot.trace boot.debug1"
 
 # Trap the CPU on compressed instructions?
-TRAP_COMPRESSED="-cpu rv64,c=false"
+#TRAP_COMPRESSED="-cpu rv64,c=false"
 
 CUSTOM_BIOS="-bios $OPENSBI/share/opensbi/lp64/generic/firmware/fw_payload.bin"
 #CUSTOM_BIOS="-bios $OPENSBI/share/opensbi/lp64/generic/firmware/fw_jump.elf"
@@ -45,11 +45,10 @@ CUSTOM_BIOS="-bios $OPENSBI/share/opensbi/lp64/generic/firmware/fw_payload.bin"
 #CUSTOM_BIOS="-bios $CDIR/bios.bin"
 #CUSTOM_BIOS="-bios opensbi-1.4-rv-bin/share/opensbi/lp64/generic/firmware/fw_payload.bin"
 #DEBUG_GDB="-s -S"
-DEBUG_CPU="-d cpu_reset"
+#DEBUG_CPU="-d cpu_reset"
 #DEBUG_CPU="-d in_asm,cpu,cpu_reset"
 
 
-# Start QEMU.
 exec qemu-system-riscv64 \
     $DEBUG_GDB \
     $DEBUG_CPU \
@@ -60,18 +59,16 @@ exec qemu-system-riscv64 \
     -machine virt \
     -device virtio-rng-pci \
     $TRAP_COMPRESSED \
-    $CUSTOM_BIOS \
-    -netdev user,id=net0,hostfwd=tcp::60022-:22 -device virtio-net-device,netdev=net0 \
+    -netdev user,id=net0,hostfwd=tcp::60022-:22 \
+    -device virtio-net-device,netdev=net0 \
     -virtfs local,path=/nix/store,security_model=none,mount_tag=nix-store \
     -virtfs local,path="${SHARED_DIR:-$TMPDIR/xchg}",security_model=none,mount_tag=shared \
     -virtfs local,path="$TMPDIR"/xchg,security_model=none,mount_tag=xchg \
-    -device virtio-keyboard \
     -drive "file=$NIX_DISK_IMAGE,if=none,id=hd0" \
     -device virtio-blk-device,drive=hd0 \
-    -device loader,addr=0x84000000,file=$system/kernel \
     -kernel $system/kernel \
     -initrd $system/initrd \
-    -append "$(cat $system/kernel-params) init=$system/init console=ttyS0,115200n8 loglevel=7 $QEMU_KERNEL_PARAMS" 
+    -append "$(cat $system/kernel-params) init=$system/init console=ttyS0,115200n8 loglevel=7 $QEMU_KERNEL_PARAMS" \
     $QEMU_OPTS \
     "$@"