[PATCH V2 0/3] hw/riscv: virt: Enable booting S-mode firmware from pflash

[Sunil V L]

This series adds the support to boot S-mode FW like EDK2 from the flash. The
S-mode firmware should be kept in pflash unit 1.

When -kernel (and -initrd) option is also provided along with the flash,
the kernel (and initrd) will be loaded into fw_cfg table and opensbi will
branch to the flash address which will be the entry point of the S-mode
firmware. The S-mode FW then loads and launches the kernel.

When only -pflash option is provided in the command line, the kernel
will be located and loaded in the usual way by the S-mode firmware.

These patches are available in below branch.
https://github.com/vlsunil/qemu/tree/pflash_v2

The first two patches in this series are refactor patches.

These changes are tested with a WIP EDK2 port for virt machine. Below
are the instructions to build and test this feature.

1) Get EDK2 sources from below branches.
https://github.com/vlsunil/edk2/tree/virt_refactor_smode_v1
https://github.com/vlsunil/edk2-platforms/tree/virt_refactor_smode_v1

2) Build EDK2 for RISC-V
        export WORKSPACE=`pwd`
        export GCC5_RISCV64_PREFIX=riscv64-linux-gnu-
        export PACKAGES_PATH=$WORKSPACE/edk2:$WORKSPACE/edk2-platforms
        export EDK_TOOLS_PATH=$WORKSPACE/edk2/BaseTools
        source edk2/edksetup.sh
        make -C edk2/BaseTools clean
        make -C edk2/BaseTools
        make -C edk2/BaseTools/Source/C
        source edk2/edksetup.sh BaseTools
        build -a RISCV64  -p Platform/Qemu/RiscVVirt/RiscVVirt.dsc -t GCC5

3)Make the EDK2 image size to match with what qemu flash expects
truncate -s 32M Build/RiscVVirt/DEBUG_GCC5/FV/RISCV_VIRT.fd

4) Run
a) Boot to EFI shell (no -kernel / -initrd option)
qemu-system-riscv64  -nographic   -drive 
file=Build/RiscVVirt/DEBUG_GCC5/FV/RISCV_VIRT.fd,if=pflash,format=raw,unit=1  
-machine virt -M 2G

b) With -kernel, -initrd and -pflash
qemu-system-riscv64  -nographic   -drive 
file=Build/RiscVVirt/DEBUG_GCC5/FV/RISCV_VIRT.fd,if=pflash,format=raw,unit=1  
-machine virt -M 2G -kernel arch/riscv/boot/Image.gz -initrd rootfs.cpio 


Changes since V1:
        1) Modified code to support the use case when both -kernel and -pflash 
are configured.
        2) Refactor patches added to help (1) above.
        3) Cover letter added with test instructions.

Sunil V L (3):
  hw/arm,loongarch: Move load_image_to_fw_cfg() to common location
  hw/riscv: virt: Move create_fw_cfg() prior to loading kernel
  hw/riscv: virt: Enable booting S-mode firmware from pflash

 hw/arm/boot.c             | 49 ---------------------------------------
 hw/loongarch/virt.c       | 33 --------------------------
 hw/nvram/fw_cfg.c         | 49 +++++++++++++++++++++++++++++++++++++++
 hw/riscv/boot.c           | 28 ++++++++++++++++++++++
 hw/riscv/virt.c           | 31 ++++++++++++++++++-------
 include/hw/nvram/fw_cfg.h |  3 +++
 include/hw/riscv/boot.h   |  1 +
 7 files changed, 104 insertions(+), 90 deletions(-)

-- 
2.25.1