From: Ruslan Ruslichenko <[email protected]> This patch series introduces a new ARM machine model, arm-generic-fdt, and the underlying infrastructure required to instantiate a QEMU machine entirely from a Device Tree.
Key Features in v2 This version add support for an sbsa-ref compatible platform. Major additions include: GICv3: via the FDTGenericIntc interface. GPEX PCI Host: Dynamic mapping of MMIO windows via aliases and irq routing via a new gsi-irqs property. Block Devices: New support for binding QEMU block backends to FDT nodes using blockdev. Testing: Added two new functional tests ensuring the machine can boot successfully similar sbsa-ref platform. Also addressed comments received in v1. Origin & Motivation This feature originates from the AMD QEMU repository (https://github.com/Xilinx/qemu). Currently, adding support for a new ARM board in QEMU requires writing a dedicated C source file to define the memory map, instantiate devices, and wire interrupts. Any modification to the board configuration requires a corresponding change in the source code and a rebuild of the QEMU binary. This series introduces an alternative approach: defining the board configuration via a Device Tree Blob (DTB) provided at the command line. The new arm-generic-fdt machine parses this DTB at runtime to dynamically construct the system topology. Beyond providing more flexible board creation, this infrastructure is a prerequisite for enabling Hardware Co-Simulation workflows (e.g., using the Remote-Port protocol: https://mail.gnu.org/archive/html/qemu-devel/2026-02/msg01760.html). In mixed simulation environments where QEMU emulates the CPU subsystem and an external simulator (such as SystemC) handles custom logic, the memory map and interrupt lines often need to change dynamically based on the external hardware configuration, making static C models impractical. Implementation Overview The series implements an FDT loading framework in hw/core/fdt_generic_util.c capable of: Parsing and creating device models from FDT nodes. Setting QOM properties based on FDT properties. Connecting IRQs for SysBus devices (via FDTGenericIntc). Mapping memory regions for IO devices or system RAM (via FDTGenericMMap). Attaching block devices specified via blockdev interface. NOTE: GPIO wiring for non-SysBus devices is not supported yet. Testing Testing can be performed by two scripts within patch series. Pre-compiled dtb binaries for tests are currently placed at tests/data/dtb/aarch64/arm-generic-fdt. The Device Trees sources used for testing can be found by following links: Hardware DTS (used with -hw-dtb): https://gist.github.com/ruslichenkor/82245d89fb2a64dc7f1b694504cb840e#file-arm64-sbsa-hw-dts Guest DTS (used with -dtb): https://gist.github.com/ruslichenkor/82245d89fb2a64dc7f1b694504cb840e#file-arm64-sbsa-guest-dts Also example command to launch VM is following: /qemu/build/qemu-system-aarch64 -machine arm-generic-fdt \ -hw-dtb arm64-sbsa-hw.dtb -dtb sbsa-ref.dtb -serial mon:stdio \ -netdev user,id=net0 -device e1000e,netdev=net0 \ -device bochs-display \ -blockdev driver=file,filename=./SBSA_FLASH0.fd,node-name=pflash0 \ -blockdev driver=file,filename=./SBSA_FLASH1.fd,node-name=pflash1 \ -device usb-kbd -device usb-tablet \ -drive file=./alpine-standard-3.23.3-aarch64.iso,if=none,id=cdrom0,readonly=on \ -device ide-cd,bus=ahci.0,unit=0,drive=cdrom0 Open Questions Location of Test Binaries: I have added the compiled Device Tree Blobs (DTB) required for the functional tests into tests/data/dtb. Question: Is this the preferred location for static test binaries, or should they be placed elsewhere? Patch Summary hw/core: Add Generic FDT parsing infrastructure and utility functions (fdt_generic_util) hw/arm: Add the arm-generic-fdt machine model hw/core/sysbus: Add IO memory mapping for standard SysBus devices system/memory: Allow MemoryRegions to be configured from FDT hw/intc: Add FDT support for ARM GICv3 (IRQ translation and default wiring) hw/pci-host: Add gsi-irqs property for INTx mapping target/arm: Add FDT support for CPU timers BR, Ruslan Ruslichenko Ruslan Ruslichenko (33): system/device_tree: update qemu_fdt_getprop_cell system/device_tree: add few parsing and traversal helpers util/log: add log entry for fdt generic utils hw/core: introduce generic FDT device model registry hw/core/fdt_generic: implement FDT machine creation helpers hw/core/fdt_generic: add cpu clusters management hw/core/fdt_generic_util: implement main fdt parse routine hw/core/fdt_generic_util: implement fdt_init_qdev qdev: Add qdev_prop_get_array_elem_type() helper hw/core/fdt_generic_util: initilize qdev properties from fdt hw/core/fdt_generic_util: actually realize device hw/core/fdt_generic_util: add TYPE_FDT_GENERIC_MMAP hw/core/fdt_generic_util: add TYPE_FDT_GENERIC_INTC hw/core/fdt_generic_util: implement fdt_get_irq/_info API hw/core/fdt_generic_util: map device memory hw/core/fdt_generic_util: Connect device irqs hw/core/fdt_generic_util: realize cpu clusters hw/core: add fdt_generic to the build hw/core/machine: add '-hw-dtb' option for machine hw/arm: add generic ARM machine initialized by FDT hw/core/sysbus: implement FDT_GENERIC_MMAP_CLASS interface hw/intc/arm_gic: implement FDT_GENERIC_INTC and fdt support target/arm/cpu: add fdt support for armv8-timer qom/object: export object_resolve_link() system/memory: add setters for MemoryRegion properties system/memory: implement FDT_GENERIC_MMAP interface hw/core/fdt_generic_util: initialize serial devices system/memory: add QOM aliases for fdt support hw/intc/arm_gicv3: Implement FDTGenericIntc interface hw/core/fdt_generic_util: Add deferred device initialization support hw/core/fdt_generic_util: Add blockdev binding support hw/pci-host: add gsi-irqs property array tests/functional: Add functional tests for arm-generic-fdt machine hw/arm/arm_generic_fdt.c | 180 +++ hw/arm/boot.c | 8 +- hw/arm/meson.build | 2 + hw/arm/raspi4b.c | 8 +- hw/arm/vexpress.c | 4 +- hw/core/fdt_generic.c | 286 ++++ hw/core/fdt_generic_util.c | 1414 +++++++++++++++++ hw/core/machine.c | 19 + hw/core/meson.build | 2 + hw/core/qdev-properties.c | 12 + hw/core/sysbus.c | 28 + hw/intc/arm_gic.c | 32 + hw/intc/arm_gic_common.c | 50 + hw/intc/arm_gicv3.c | 45 + hw/intc/arm_gicv3_common.c | 68 + hw/pci-host/gpex.c | 6 + include/hw/core/boards.h | 1 + include/hw/core/fdt_generic.h | 135 ++ include/hw/core/fdt_generic_util.h | 140 ++ include/hw/core/qdev-properties.h | 1 + include/hw/pci-host/gpex.h | 3 + include/qemu/log.h | 1 + include/qom/object.h | 12 + include/system/device_tree.h | 35 +- qemu-options.hx | 9 + qom/object.c | 2 +- system/device_tree.c | 237 ++- system/memory.c | 378 ++++- system/vl.c | 3 + target/arm/cpu.c | 115 ++ .../arm-generic-fdt/arm64-sbsa-guest.dtb | Bin 0 -> 673 bytes .../aarch64/arm-generic-fdt/arm64-sbsa-hw.dtb | Bin 0 -> 5414 bytes tests/functional/aarch64/meson.build | 2 + .../aarch64/test_arm_generic_fdt.py | 114 ++ .../aarch64/test_arm_generic_fdt_alpine.py | 61 + util/log.c | 1 + 36 files changed, 3386 insertions(+), 28 deletions(-) create mode 100644 hw/arm/arm_generic_fdt.c create mode 100644 hw/core/fdt_generic.c create mode 100644 hw/core/fdt_generic_util.c create mode 100644 include/hw/core/fdt_generic.h create mode 100644 include/hw/core/fdt_generic_util.h create mode 100644 tests/data/dtb/aarch64/arm-generic-fdt/arm64-sbsa-guest.dtb create mode 100644 tests/data/dtb/aarch64/arm-generic-fdt/arm64-sbsa-hw.dtb create mode 100755 tests/functional/aarch64/test_arm_generic_fdt.py create mode 100755 tests/functional/aarch64/test_arm_generic_fdt_alpine.py -- 2.43.0
