PoC : How to build and test ACPI enabled kernel

Prerequisites:

1) You will need to install a RISC-V toolchain. It is recommended to install a toolchain from your distro. This can be done by using your distro’s installed (apt, dnf, pacman or something similar) and searching for riscv64 and installing gcc.

2) https://risc-v-getting-started-guide.readthedocs.io/en/latest/linux-qemu.html#prerequisites

Getting the sources

First, create a working directory, where we’ll download and build all the sources.

WORK_DIR=$PWD/riscv64-acpi
mkdir -p $WORK_DIR
cd $WORK_DIR

Then download all the required sources, which are:

qemu

linux

edk2

git clone --branch riscv_acpi https://github.com/ventanamicro/qemu.git qemu
git clone --branch riscv_acpi https://github.com/ventanamicro/linux.git linux
git clone --recurse-submodule [email protected]:tianocore/edk2.git edk2

Building

Build QEMU with the RISC-V target:

cd $WORK_DIR/qemu
./configure --target-list=riscv64-softmmu
make -j $(nproc)

Build EDK2 firmware for the RISC-V target as per instructions here.

Resize the EDK2 firmware image to 32M (Modify the path to RISCV_VIRT_CODE.fd and RISCV_VIRT_VARS.fd accordingly)

truncate -s 32M Build/RiscVVirtQemu/RELEASE_GCC5/FV/RISCV_VIRT_CODE.fd

truncate -s 32M Build/RiscVVirtQemu/RELEASE_GCC5/FV/RISCV_VIRT_VARS.fd

Build Linux for the RISC-V target.

cd $WORK_DIR/linux
make ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- defconfig
make ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- -j $(nproc)

Rootfs

You can use any rootfs of your choice. This example uses buildroot.

Running

ACPI is supported on system with 3 different interrupt controllers. Just change the -machine option as below while running qemu.

1) With APLIC and IMSIC: -machine virt,aia=aplic-imsic

2) With APLIC only: -machine virt,aia=aplic

3) With PLIC: -machine virt

Example with APLIC-IMSIC

$WORK_DIR/qemu/build/qemu-system-riscv64 -nographic \
 -M virt,pflash0=pflash0,pflash1=pflash1,aia=aplic-imsic \
 -m 4G -smp 8 \
 -serial mon:stdio \
 -device virtio-gpu-pci -full-screen \
 -device qemu-xhci \
 -device usb-kbd \
 -numa node,mem=2G \
 -numa node,mem=2G \
 -blockdev node-name=pflash0,driver=file,read-only=on,filename=Build/RiscVVirtQemu/RELEASE_GCC5/FV/RISCV_VIRT_CODE.fd \
 -blockdev node-name=pflash1,driver=file,filename=Build/RiscVVirtQemu/RELEASE_GCC5/FV/RISCV_VIRT_VARS.fd \
 -netdev user,id=net0 -device virtio-net-pci,netdev=net0 \
 -kernel linux/arch/riscv/boot/Image \
 -initrd rootfs.cpio \
 -append "root=/dev/ram ro console=ttyS0 rootwait earlycon=uart8250,mmio,0x10000000"